TY - JOUR A1 - Christl, Manfred A1 - Braun, Martin A1 - Müller, Germar T1 - 1,2,4-Cyclohexatriene, an Isobenzene, and Bicyclo[4.4.0)deca-1,3,5,7,8-pentaene, an Isonaphthalene: Generation and Trapping Reactions N2 - No abstract available KW - Organische Chemie Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58639 ER - TY - JOUR A1 - Christl, Manfred A1 - Kemmer, P. A1 - Mattauch, B. T1 - 1-Methylbenzvalen. Synthese und einige Reaktionen N2 - No abstract available KW - Organische Chemie Y1 - 1986 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58270 ER - TY - JOUR A1 - Christl, Manfred A1 - Herzog, C. T1 - 3-(Phenylsulfonyl)tricyclo[4.1.0.0\(^{2,7}\)]hept-4-en-3-yllithium N2 - Phenyl(tricyclo[4.1.0.0\^(^{2,7}\)] hept-4-en-3-yl)sulfone 8 has been prepared in two steps from 4,S-dlbromohomobenzvalene (6) and deprotonated to give the title compound 9. The carbon-13 NMR spectrum of 9 reveals a considerable interaction between the allyl anion moiety and the bicyclobutane system. KW - Organische Chemie Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58340 ER - TY - JOUR A1 - Christl, Manfred A1 - Nusser, R. A1 - Herzog, C. T1 - 4-Bromoctavalen und zwei (Brommethylen)homobenzvalene anstelle eines erwarteten Bromoctabisvalens N2 - No abstract available. KW - Organische Chemie Y1 - 1988 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58409 ER - TY - JOUR A1 - Christl, Manfred A1 - Schreck, M. T1 - 7-Arylbicyclo[4.2.0]oct-1-ene - Synthese durch [2+2]-Cycloadditionen von 1,2-Cyclohexadien sowie 1-Methyl-1,2-cyclohexadien und thermische Äquilibrierung der exo/endo-Isomeren T1 - 7-Arylbicyclo[4.2.0]oct-1-eaes - Synthesis by [2+2]Cycloadditions of 1,2-Cyclohexadiene and 1-Methyl-l,l-cyclohexadiene and Thermal Equilibration of the exo/endo Isomers N2 - Das exo/endo--lsomerenverhältnis Ja: Jb bei der bekannten [2 + 2]-Cycloaddition von Styrol an 1,2-Cyclohexadien (2) wurde als tempcraturabhingiaaefunden. Der Einsatz von (Z)-Dcutcriostyrollicfene den Beweis der Zweistufiakeit dieser Reaktion, und das Diradikal 4 wird als wahrscheinlichste Zwischenstufe anaesehen. Erhitzen von Jb auf 140-170°C führte zur Binstellung des thermodynamischen Gleichgewichts mit Ja (Ja:3b = 93:7), wobei wieder das Diradikal4 als Zwischenstufe fungieren dürfte. Mit Hilfe kinetischer Messungen ermittelte man die Aktivierungsparameter für das System Ja~ 3b. - Aus 2 und den Abfangreagenzien p-Methoxystyrol, 1,1-Diphenylethylen sowie 1-Phenylpropen gingen mit bescheidenen Ausbeuten die Titelverbindungen 6a, b, 7 bzw. 8 hervor. Analoa zu 2 wurde sein l-Methylderivat 13 aus 6,6-Dibrom-1-methylbicyclo[3.1.0]hexan (9) durch Methyllithium freigesetzt. In Gegenwart von Styrol entstand neben den Abfanaprodukten 14a, b auch das Dimere 12 von lJ. - Die 1H-NMR-Spektren der Titelverbindungen belegen eine starre Halbsesselkonformation des Cyclohexentcils mit äquatorial anellienem Cyclobutanring. N2 - The exofendo ratio of tbe isomers 3a, b formed in the kuown [2 + 2] cycloaddition of styrene to 1 ,2-cyclohexadiene (2) has been found to depend on the tempcrature. The utilization of (Z)deuteriostyrene provided the proof of the stepwise nature of this reaction with thc diradical 4 as the most probable intennediatc. Heating of 3b at l40-170°C established the thermodynamic equilibrium between Ja and Jb (3a:3b = 93:7) and again 4 is assumed to be the intermediatc. By means of kinetic measurements the activation parameten ofthe system 3a ~ Jb have been detcrmined. - From 2 and the trapping reagents p-metboxystyrene, 1,1-diphenylethylene, and 1-phenylpropene the title compounds 6a, b, 7, and 8, respectively, were formed in low yields. In analogy to 2 its 1-methyl derivative 13 has been generated from 6,6-dibromo-l-methylbicyclo[3.t.O]hexane (9) with methyUithium. From the reaction in the presence of styrcne the trappina products 14a, b were isolated in addition to the dimer ll of 13. - The 1H NMR spectra of the title compounds support a rigid halfchair conformation of the cyclohexene moiety with the cyclobutane ring ancllatcd equatorially. KW - Organische Chemie Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58352 ER - TY - JOUR A1 - Christl, Manfred A1 - Brunn, E. A1 - Roth, W. R. A1 - Lennartz, H.-W. T1 - 7-Methyl- and 7-Phenylcyclohepta-1,3,5-trienes from Benzvalene Via 3,3a,4,5,6,6a-Hexahydro-4,5,6-methenocyclopentapyrazoles and Tetracyclo[4.1.0.0\(^{2,4}\).0\(^{3,5}\)]heptanes N2 - No abstract available KW - Organische Chemie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58471 ER - TY - JOUR A1 - Leininger, H. A1 - Kemmer, P. A1 - Beck, K. A1 - Christl, M. T1 - 7-Thiatetracyclo[4.1.0.0\(^{2,4}\).0\(^{3,5}\)]heptan (Benzvalensulfid) - Synthese und Reaktionen N2 - No abstract available KW - Organische Chemie Y1 - 1982 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58113 ER - TY - JOUR A1 - Christl, Manfred T1 - \(^{13}\)-NMR-Spektren von Bicyclo[n.1.0]kohlenwasserstoffen N2 - No abstract available KW - Organische Chemie Y1 - 1975 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-57977 ER - TY - JOUR A1 - Christl, Manfred A1 - Warren, J. D. A1 - Hawkins, B. L. A1 - Roberts, J. D. T1 - \(^{13}\)C and \(^{15}\)N Nuclear Magnetic Resonance Spectroscopy of Nitrile Oxides and Related Reaction Products : Unexpected \(^{13}\)C and \(^{15}\)N Nuclear Magnetic Resonance Parameters of 2,4,6-Trimethylbenzonitrile Oxide N2 - No abstract available KW - Organische Chemie Y1 - 1973 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-57894 ER - TY - JOUR A1 - Christl, Manfred A1 - Herzog, C. T1 - \(^{13}\)C-NMR-Spektroskopie: Besondere Hochfeldeffekte in Bicyclo[4.1.1]- und Tricyclo[5.1.0.0\(^{2,8}\)]octan-Systemen (1,3-Cycloheptadien-Effekt) und besondere Tieffeldeffekte in Dihalogenbicyclo[2.1.1]hex-2-enen (Cyclopenten-Effekt) N2 - No abstract available KW - Organische Chemie Y1 - 1986 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58334 ER - TY - JOUR A1 - Froudakis, G. A1 - Zdetsis, A. A1 - Mühlhäuser, M. A1 - Engels, Bernd A1 - Peyerimhoff, S. D. T1 - A comparative ab initio study of the Si\(_2\)C\(_4\), Si\(_3\)C\(_3\), Si\(_4\)C\(_2\) clusters N2 - Various structural possibilities for the Si\(_2\)C\(_4\) and Si\(_4\)C\(_2\) clusters are investigated by employing a basis set of triple-zeta plus polarization quality; electron correlation is generally accounted for by second-order M0ller-Plesset and, in certain instances, by higher-order perturbation (CASPT2) approaches. The building-up principle recently suggested from an analysis of Si\(_3\)C\(_3\) clusters is found to be fully operative for Si\(_2\)C\(_4\) and Si\(_4\)C\(_2\) clusters. A comparison of the structure and stability of various geometrical arrangements in the series C\(_6\) , Si\(_2\)C\(_4\) , Si\(_3\)C\(_3\) , Si\(_4\)C\(_2\), and Si\(_6\) shows that linear and planar structures become rapidly less stable if carbons are replaced by silicons and that the three-dimensional bipyramidal forms become less favorable as soon as silicons are exchanged by carbons in the parent Si\(_6\) structure. The effects can be rationalized in qualitative terms based on differences in silicon and carbon bonding. KW - Organische Chemie Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59097 ER - TY - JOUR A1 - Suter, H. U. A1 - Huang, M.-B. A1 - Engels, Bernd T1 - A Multireference Configuration Interaction Study of the Hyperfine Structure of the Molecules CCO, CNN and NCN in their triplet ground states N2 - The hyperfine structures of the isoelectronic molecules CCO. CNN, and NCN in their triplet ground states (X\(^3 \sum ^-\)) are investigated by means of ab initio methods. The infrared frequencies and geometries are detennined and compared with experiment. Configuration selected multireference configuration interaction calculations in combination with perturbation theory to correct the wave function (MRD-CI/B\(_K\)) employing extended atomic orbital (AO) basis sets yielded very accurate hyperfine properties. The theoretical values for CCO are in excellent agreement with the experimental values determined by Smith and Weltner [J. Chem. Phys. 62,4592 (1975)]. For CNN, the first assignment of Smith and Weltner for the two nitrogen atoms has to be changed. A qualitative discussion of the electronic structure discloses no simple relation between the structure of the singly occupied orbitals and the measured hyperfine coupling constants. Vibrational effects were found to be of little importance. KW - Organische Chemie Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59108 ER - TY - JOUR A1 - Peric, M. A1 - Engels, Bernd T1 - Ab initio calculation of the vibronically averaged hyperfine coupling constants in the 1\(^2\)Π\(_u\) electronic state of CH\(_2 ^+\) N2 - The results of pure ab initio calculations of the hyperfine coupling constants for the 1 \(^2 \pi _u\) electronic state for various isotopomers of CHi in the energy range between 0 and 20 000 cm\(^{-1}\) are presented. Effects of vibronic and spin-orbit coupling are discussed. KW - Organische Chemie Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58951 ER - TY - JOUR A1 - Staikova, M. A1 - Engels, Bernd A1 - Peric, M. A1 - Peyerimhoff, S. D. T1 - Ab initio calculation of the vibronically averaged hyperfine coupling constants in the two lowest electronic states of H\(_2\)O\(^+\) N2 - No abstract available T2 - Ab initio calculations of the vibronically averaged hyperfine coupling constants in the 1\(^2\)Π\(_u\)(X\(^2\)B\(_1\),A\(^2\)A\(_1\)) state of the water cation KW - Organische Chemie Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58998 ER - TY - JOUR A1 - Peric, M. A1 - Engels, Bernd T1 - Ab initio calculations of the vibronically averaged values for the hyperfine coupling constants in NH\(_2\), NHD and ND\(_2\) N2 - Vibronically averaged values for K =0 and K = 1 bending levels in the energy range between 0 and 25 000 cm\(^{-1}\) are computed for the \(^{14}\)N, H, and D atoms in NH\(_2\), NHD, and ND\(_2\) The pure ab initio electronic potentials, as well as those derived by fitting of experimentally observed band positions are employed. Effects of vibronic coupling and local perturbations of close-lying levels belanging to different electronic states are discussed. KW - Organische Chemie Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58941 ER - TY - JOUR A1 - Karna, S.P. A1 - Grein, F. A1 - Engels, Bernd A1 - Peyerimhoff, S.D. T1 - Ab initio configuration-interaction studies of the ground state potential energy and hyperfine coupling constants of \(^{35}\)Cl\(_2^-\) N2 - Potential energy and spectroscopic constants for the X\(^2 \sum^+ _\mu\) ground state of a;, were calculated by configuration-interaction (Cl) methods, using large basis sets with polarization and diffuse functions. From these CI wavefunctions, the isotropic (a\(_{iso}\)) and dipolar (A\(_{dip}\)) components of the hyperfine coupling constant were obtained. The effects of various s, p basis sets, polarization and diffuse functions, as well as the influence of reference configurations and configuration selection thresholds were investigated. The best values obtained are 35·31 G for a\(_{iso}\) and 29·440 for A\(_{dip}\)• tobe compared with experimental values of 37 ± 1 G and 32 ± 1 G, respectively. It is shown that the contributions to a1so of the K and L shells are opposite in sign, differing by about 4 G. Upon vibrational averaging, both a\(_{iso}\) and A\(_{dip}\) move towards smaller values as v increases. An adiabatic electron affinity of 2·46eV was obtained for CL\(_2\) , and a vertical electron detachment energy of 3·71 eV for Cl;. KW - Organische Chemie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58869 ER - TY - JOUR A1 - Staikova, M. A1 - Engels, Bernd A1 - Peric, M. T1 - Ab initio investigation of the hyperfine structure in the 1\(^2\)Π\(_u\)(X\(^2\)A\(_1\), A\(^2\)B\(_1\) system of BH\(_2\)) N2 - No abstract available KW - Organische Chemie Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59000 ER - TY - JOUR A1 - Mühlhäuser, M. A1 - Froudakis, G. A1 - Zdetsis, A. A1 - Engels, Bernd A1 - Flytzanis, N. A1 - Peyerimhoff, S. D. T1 - Ab initio investigation of the stability of Si\(_3\)C<\(_3\) clusters and their structural and bonding features N2 - Various structural possibilities for Si\(_3\)C\(_3\) clusters are investigated by ab initio calculations employing basis sets of double- and triple-zeta quality augmented by d polarization functions. Correlation effects are included by a second-order Moeller Piesset perturbation treatment. For the two lowest-lying structures higher-order correlation corrections and multi-reference effects are also included. Bonding features are investigated by two different types of population analyses to obtain insight into the nature of chemical bonding. A total of 17 stationary points were investigated, 14 of which correspond to local minima and three being transition states. The energetically lowest-lying structures are: A "pyramidlike" structure with various multicenter bonds, followed by a es symmetric isomer closely related to the ground state Si6 structure. Planar structures, favoured in small carbon clusters, lie higher in energy and are transition states. The lowest-lying triplet system is found to be the linear nonsymmetric Si - C-C-C-Si -Si structure, which is calculated to lie about 38 kcalfmole above the singlet ground state. A building-up principle based on bonding criteria is suggested for the occurence of the various structural possibilities. KW - Organische Chemie Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59060 ER - TY - JOUR A1 - Staikova, M. A1 - Peric, M. A1 - Engels, Bernd A1 - Peyerimhoff, S. D. T1 - Ab initio Investigation of the Structure of the X\(^2\)A', A\(^2\)A'' (1\(^2\)Π) Spectral System of HCO: Investigation of the Magnetic Hyperfine Effects N2 - Results ofan ab initio study ofthe hyperfine structure of the X\(^2\)A', A\(^2\) A" ( 1\(^2 \Pi\)) system ofthe formyl radical are presented. Special attention is paid to the analysis of the interplay between the vibronic and magnetic hyperfine etfects. The results of computations are in very good agreement with the available experimental findings. The values for the hyperfine coupling constants in lower bending Ievels of both electronic species are predicted. KW - Organische Chemie Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59089 ER - TY - JOUR A1 - Peric, M. A1 - Engels, Bernd A1 - Peyerimhoff, S.D. T1 - Ab initio investigation of the vibronic structure of the C\(_2\)H spectrum Calculation of the hyperfine coupling constants for the three lowest lying electronic states N2 - The hyperfine coupling constants (isotropic hfcc and four Cartesian components of the ani~ tropic tensor) are calculated for all three atoms of C\(_2\)H in its three lowest-lying electronic states at various molecu)ar geometries by means of the ab initio configuration interaction ( MRO.CI) method. The off-diagonal electronic matrix elements involving the two species ofthe A' symmetry are also computed. A diabatic transforrnation is perforrned Jeading to simple geometrical depen· dences of the hyperline coupling constants. KW - Organische Chemie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58901 ER - TY - JOUR A1 - Peric, M. A1 - Engels, Bernd A1 - Peyerimhoff, S.D. T1 - Ab initio investigation of the vibronic structure of the C\(_2\)H spectrum Computation of the vibronically-averaged values for the Hyperfine Coupling Constants N2 - The vibronically averaged values for tbe hyperfine coupling constants in the X\(^2 \sum\)-A\(^2 \Pi\) system of the ethynyl radical are computed by means of tbe ab initio metbod calculations. The results point at tbe importance of taking into account the coupling of a1l tbree electronic states in question ( I\(^2\)A', 2\(^2\)A', and 1\(^2\)A") for a reliable explanation of the available experimental findings. The mean values of the hfcc's for K = 0 and 1 levels in \(^{13}\)C\(_2\)H and \(^{13}\)C\(_2\)D in the energy range up to 6000 cm\(^{-1}\) are predicted. KW - Organische Chemie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58915 ER - TY - JOUR A1 - Pleß, V. A1 - Suter, H. U. A1 - Engels, Bernd T1 - Ab initio study of the energy difference between the benzene and the cumulene form of the C\(_6\) molecule N2 - The energy difference between the three lowest-lying isomers of C\(_6\) the linear \(^3 \sum ^-\) state and the two ring forms,the benzene structure (\(^1\)A\(_{18}\)) possessing D\(_{6h}\) symmetry and a distorted cyclic form ( \(^1\)A'\(_1\), D\(_{3h}\) symmetry) have been calculated using various ab initio methods. Variational methods such as multireference configuration interaction (MR-CI) and complete active space second order perturbatiOn treatment (CASPT2) have been applied, as weil as perturbational treatments and coupled cluster calculations (CCD). The correlation of all valence shell electrons is found to be important for a balanced description of the isomers of C\(_6\) . Methods which do not account for higher-order effects appropriately proved to be unsuitable for calculating the energy difference correctly. The results from multireference configuration interaction methods show that the isomers are close in energy with the cyclic forms somewhat lower than the linear form. The ring form possessing D\(_{3h}\) symmetry (\(^1\)A'\(_1\)} is found tobe the lowest-lying structure. KW - Organische Chemie Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59059 ER - TY - JOUR A1 - Bast, K. A1 - Christl, Manfred A1 - Huisgen, R. A1 - Mack, W. T1 - Additionen der Nitriloxide an CN-Mehrfachbindungen N2 - No abstract available KW - Organische Chemie Y1 - 1972 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-57879 ER - TY - JOUR A1 - Bast, K. A1 - Christl, Manfred A1 - Huisgen, R. A1 - Mack, W. A1 - Sustmann, R. T1 - Additionen des Benzonitriloxids an olefinische und acetylenische Dipolarophile N2 - No abstract available KW - Organische Chemie Y1 - 1973 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-57905 ER - TY - JOUR A1 - Christl, Manfred A1 - Mattauch, B. A1 - Irngartinger, H. A1 - Goldmann, A. T1 - Additionen von Benzvalen an Nitriloxide. Eine Synthese für Benzvalen-3-carbonitril N2 - No abstract available KW - Organische Chemie Y1 - 1986 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58269 ER - TY - JOUR A1 - Bündgen, P. A1 - Engels, Bernd A1 - Peyerimhoff, S.D. T1 - An MRD-CI study of low-lying electronic states in CaF N2 - Dipole moments and various spectroscopic constants of some low-lying electronic states of the CaF molecule have been calculated using the multireference single· and double-excitation configuration-interaction (MRD-CI) method. The electronic structure of the highly ionic molecule in various excited states can be explained in tenns of different polarisations of the mainly Cacentered valence electron in the field of the F\(^-\) anion. Plots of natural orbitals occupied by the valence electron in the different states give a qualitative picture of the charge distribution and provide a visualisation of the different polarisations of the valence electron in the various states. Comparisons with the electrostatic polarisation model ofTörring, Ernstand Kändler (TEK model) are made. The unknown A' \(^2 \Delta\) state is predicted to lie about 21200 cm\(^{-1}\) above the ground state. KW - Organische Chemie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58880 ER - TY - JOUR A1 - Gittins, C. M. A1 - Harris, N. A. A1 - Field, R. W. A1 - Verges, J. A1 - Ernst, W. E. A1 - Bündgen, P. A1 - Engels, Bernd T1 - Analysis and Depertubation of the C\(^2\)Π and D\(^2\)Σ\(^+\) states of CaF N2 - No abstract available KW - Organische Chemie Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58980 ER - TY - JOUR A1 - Herbert, R. A1 - Christl, Manfred T1 - Bicyclo[2.1.1]hexane aus Tricyclo[3.1.0.0\(^{2,6}\)]hexanen N2 - No abstract available KW - Organische Chemie Y1 - 1979 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58042 ER - TY - JOUR A1 - Christl, Manfred A1 - Herzog, C. A1 - Nusser, R. T1 - Bicyclo[4.1.1]octa-2,4-dien, -oct-2-en, -oct-3-en und -octan aus Norpinen N2 - No abstract available KW - Organische Chemie Y1 - 1986 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58326 ER - TY - JOUR A1 - Homann, Arne A1 - Qamar, Riaz-ul A1 - Serim, Sevnur A1 - Dersch, Petra A1 - Seibel, Juergen T1 - Bioorthogonal metabolic glycoengineering of human larynx carcinoma (HEp-2) cells targeting sialic acid N2 - Sialic acids are located at the termini of mammalian cell-surface glycostructures, which participate in essential interaction processes including adhesion of pathogens prior to infection and immunogenicity. Here we present the synthesis and bioorthogonal metabolic incorporation of the sialic acid analogue N-(1-oxohex-5-ynyl)neuraminic acid (Neu5Hex) into the cell-surface glycocalyx of a human larynx carcinoma cell line (HEp-2) and its fluorescence labelling by click chemistry. KW - Organische Chemie KW - bioorthogonal metabolic glycoengineering; click chemistry; sialic acid Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-67806 ER - TY - THES A1 - Peethambaran Nair Syamala, Pradeep T1 - Bolaamphiphilic Rylene Bisimides: Thermodynamics of Self-assembly and Stimuli-responsive Properties in Water T1 - Bolaamphiphile Rylenebisimide: Thermodynamik der Selbstorganisation und Stimuli-responsiven Merkmale in Wasser N2 - The present thesis demonstrates how different thermodynamic aspects of self-assembly and stimuli-responsive properties in water can be encoded on the structure of π-amphiphiles, consisting of perylene or naphthalene bisimide cores. Initially, quantitative thermodynamic insights into the entropically-driven self-assembly was studied for a series of naphthalene bisimides with UV/Vis and ITC measurements, which demonstrated that their thermodynamic profile of aggregation is heavily influenced by the OEG side chains. Subsequently, a control over the bifurcated thermal response of entropically driven and commonly observed enthalpically driven self-assembly was achieved by the modulation of glycol chain orientation. Finally, Lower Critical Solution Temperature (LCST) phenomenon observed for these dyes was investigated as a precise control of this behavior is quintessential for self-assembly studies as well as to generate ‘smart’ materials. It could be shown that the onset of phase separation for these molecules can be encoded in their imide substituents, and they are primarily determined by the supramolecular packing, rather than the hydrophobicity of individual monomers. N2 - Die vorliegende Arbeit zeigt, wie verschiedene thermodynamische Aspekte der Selbstorganisation sowie die Stimuli-responsiven Merkmale in Wasser mittels der Struktur von π-Amphiphilen mit Perylen- oder Naphthalinbisimidkernen programmiert werden können. Zunächst wurden quantitative thermodynamische Einblicke in die entropisch getriebene Selbstorganisation für eine Reihe von Naphthalinbisimiden mit UV / Vis- und ITC-Messungen untersucht. Diese zeigten, dass ihr thermodynamisches Aggregationsprofil stark von den Oligoethylenglykol-Seitenketten beeinflusst wird. Anschließend wurde durch gezielte Modulation der Glykolketten und der daraus resultierenden Neuorientierung der Ketten, eine Kontrolle über die Thermodynamik der Selbstassemblierung zwischen der häufiger beobachtbaren enthalpisch getriebenen und der entropisch getriebenen Selbstorganisation erreicht. Schließlich wurde das für diese Farbstoffe beobachtete Phänomen der niedrigeren kritischen Lösungstemperatur (LCST) untersucht, da eine genaue Kontrolle dieses Verhaltens für Selbstorganisationsstudien sowie für die Erzeugung „intelligenter“ Materialien von entscheidender Bedeutung ist. Es konnte gezeigt werden, dass der Beginn der Phasentrennung für diese Moleküle von ihren Imidsubstituenten und hauptsächlich durch die supramolekulare Packung bestimmt werden und nicht durch die Hydrophobie einzelner Monomere. KW - Supramolekulare Chemie KW - Aggregation KW - Selbstorganisation KW - Wasser KW - Supramolecular Chemistry KW - Thermodynamics KW - Self-assembly KW - Lower Critical Solution Temperature (LCST) KW - Water KW - Organische Chemie Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-213424 ER - TY - JOUR A1 - Engels, Bernd A1 - Peyerimhoff, S.D. A1 - Davidson, E.R. T1 - Calculation of hyperfine coupling constants : An ab initio MRD-CI study for nitrogen to analyse the effects of the basis sets and CI parameter N2 - The hyperfine coupling constant for the nitrogen atom is evaluated by large-scale MRD-CI calculations. A detailed analysis of the charge density at the nucleus and the spin polarization in the ls and 2s shell as a function of various technical parameters is undertaken. Various (s, p) AO basis sets and the inftuence of correlation orbitals is investigated as weil as selection threshold and other properlies in CI calculations. The best value, obtained for the isotropic hyperfine coupling constant in an s, p, d basis, based on theoretical judgment of' best' quantities, is 9·9 MHz compared to 10·4509 MHz. KW - Organische Chemie Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58784 ER - TY - JOUR A1 - Kim, E. A1 - Christl, Manfred A1 - Kochl, J. K. T1 - Charge-Transfer Cycloaddition of Homobenzvalene with Tetracyanoethylene N2 - The transient yellow color observed in the cycloaddition of homobenzvalene (HB) with tetracyanoethylene (TCNE) is associated with the charge-transfer complex [HB, TCNE). The deliberate photoexcitation of [HB,TCNE) affords a mixture of charge-transfer cycloadducts (1, 2, and 3) that differs from that obtained in thermal cycloaddition. The relationship of {HB t TCNE•) radical-ion pair (as the critical reactive intermediate in charge-transfer cycloaddition) to the activation process for thermal cycloaddition is discussed. KW - Organische Chemie KW - Electron transfer KW - photochemical KW - Radical-ion pair KW - Photochemistry Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58537 ER - TY - JOUR A1 - Christl, Manfred A1 - Lanzendörfer, U. A1 - Grötsch, M. M. A1 - Ditterich, E. A1 - Hegmann, J. T1 - Cycloadditionen von 1,3,4-0xadiazin-6-onen (4,5-Diaza-alpha-pyronen), 9 - 6-Oxo-5-phenyl-1,3,4-oxadiazin-2-carbonsäure-methylester - Synthese und Reaktionen mit Norbornen, Norbornadien, Cyclopropenen, Cyclobuten und Benzvalen N2 - No abstract available KW - Organische Chemie KW - 1 KW - 3 KW - 4-0xadiazin-6-ones KW - Diels-Alder reactions KW - y-Oxoketenes KW - ß-Lactones KW - bicyclic KW - Enol Iactones KW - alpha KW - ß-unsaturated Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58569 ER - TY - JOUR A1 - Christl, Manfred A1 - Lanzendörfer, F. A1 - Hegmann, J. A1 - Peters, K. A1 - Peters, E.-M. A1 - Schnering, H. G. von T1 - Cycloadditionen von 6-0xo-l,3,4-oxadiazinen (4,5-Diaza-α-pyronen), 3 : Reaktionen von 6-Oxo-2,5-diaryl-1,3,4-oxadiazinen mit Alkenen T1 - Cycloadditions of 6-0xo-l,3,4-oxadiazines (4,5-Diaza-α-pyrones), 3 : Reactions of 6-0xo-2,5--diaryl-l,3,4-oxadiazines with Alkenes N2 - Das bekannte 6-0xo-2,5-diphenyl-6H-l,3,4-oxadiazin (1 a) und die neuen 2,5-Diarylderivate 1 b - g lagern Alkene an, und es entstehen stickstofIfreie Produkte. Im Falle von Cyclopropenen und Cyclobuten bilden sich die a,p-ungesättigten Siebenring-Enollactone 42 -45 bzw. das a,ß-ungesättigte Achtring-Enollacton 47. 42a und d erleiden an basischem Aluminiumoxid die H-Verschiebung zu den ß,y-ungesättigten Siebenring-Enollactonen 46a bzw. d. Bei weiteren Olefinen wurden die 'Y-Ketoketene des Typs 33 als Zwischenprodukte nachgewiesen oder sind aufgrund der Konstitution der Endprodukte wahrscheinlich. Aus 1 a werden mit Norbomen, Norbornadien, Cyc1openten, trans-Cycloocten und Styrol die Sechsring-Enollactone 10, 13, 15, 19 bzw. 21 und 22 erhalten. 10 isomerisiert mit Kalium-tert-butoxid zu 34, und die Methanolyse dieser Enollactone erbringt die diastereomeren Methy]ester 12 bzw. 35. Das y-Ketoketen 16 aus trans-Cycloocten nimmt schneller Wasser und Methanol zu 17 bzw. 18 auf als es zum Enollacton 19 cyclisiert. cis,trans-l,5-Cyc1ooctadien erbringt über die Stufe des nachgewiesenen y-Ketoketens 40 in einer intramolekularen [2 + 2J-Cyc1oaddition den Tricyclus 41. Tetracyclische Verbindungen des Typs 4 gehen aus der Umsetzung von Benzvalen (2) mit 1 hervor. Durch Röntgenstrukturanalysen wurden Konstitution und Konfiguration von 10, 19 und 41 aufgeklärt N2 - Cycloaddition of the known 6-oxo-2,5-diphenyl-6H-1,3,4-oxadiazine (1 a) and the new 2,5- diaryl derivatives 1 b - g with various alkenes yield nitrogen free products. Using cyclopropenes and cyclobutene, a,~-unsaturated seven-membered enollactones 42-45 and the C't,ßunsaturated eight-membered enollactone 47 are formed, respectively. In the presenee of basic aluminium oxide 42a and d undergo a hydrogen migration to form the ß.y-unsaturated enollactones 46a and d, respectively. With other alkenes, y-ketoketenes 33 have been observed, or are assumed to be intennediates, based on the structure of the isolated products. Tbe six-mernbered enollactones 10, 13, 15, 19, and 21 and 22 have been obtained with norbomene, norbornadiene, cyclopentene, trans-cyclooctene, and styrene. Cornpound 10 isomerizes to 34 on treatment with potassium tert-butoxide. The rnethanolyses of these enollactones result in the formation of the diastereomeric methyl esters 12 and 35. The yketoketene 16 forrned from trans-cyc1ooctene gives acid 17 and ester 18 with water and methanol, respectively. These reactions are faster than the cyc1ization to enollactone 19. From cis,trans-l,5-cyclooctadiene the more short-lived y-ketoketene 40 is formed. which undergoes intramolecular [2 + 2] cycloaddition, giving rise to the tricyclic cyclobutanone derivative 41. Tetracyclic products of type 4 are generated from benzvalene (2) and 1. The structures and configurations of compounds 10, 19, and 41 have been determined by means of X -ray analyses. KW - Organische Chemie Y1 - 1985 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58191 ER - TY - JOUR A1 - Christl, Manfred A1 - Lanzendörfer, U. A1 - Grötsch, M. M. A1 - Hegmann, J. A1 - Ditterich, E. A1 - Hüttner, G. A1 - Peters, K. A1 - Peters, E.-M. A1 - Schnering, H. G. von T1 - Cycloadditionen von 6H-1,3,4-0xadiazin-6-onen (4,5-Diaza-α-pyronen), 12 - Dieckmann-Kondensationen ohne Basen T1 - Cycloadditions of 6H-1,3,4-0xadiazin-6-ones (4,5-Diaza-α-pyrones), 12 - Dieckmann Condensations without Bases N2 - No abstract available KW - Organische Chemie KW - 1 KW - 3 KW - 4-0xadiazine-2-carboxylate KW - methyl 6-oxo-5-phenyl- KW - Diels-Alder reactions KW - Ketenes KW - y-oxo- KW - 1 KW - 2-Cyclopentanedione derivatives KW - Adipic acid KW - substituted 2-oxo- dimethyl esters Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58665 ER - TY - JOUR A1 - Feineis, E. A1 - Schwarz, H. A1 - Hegmann, J. A1 - Christl, Manfred A1 - Peters, K. A1 - Peters, E.-M. A1 - Schnering, H. G. von T1 - Cycloadditionen von 6H-1,3,4-0xadiazin-6-onen (4,5-Diaza-α-pyronen), 13 - Diels-Alder-Reaktionen mit 6H-1,3,4-Oxadiazin-6-onen als Dienophil T1 - Cycloaddltions of 6H-1,3,4-0xadiazin-6-ones (4,5-Diaza-α-pyrones), 13 - Diels-Alder Reactions wtth 6H-1,3,4-0xadiazin-6-ones as Dienophile N2 - No abstract available KW - Organische Chemie KW - 6H-1 KW - 3 KW - 4-0xadiazin-6-ones KW - 1 KW - 2-Bismethylenecyclohexane KW - Diels-Alder reactions KW - [1 KW - 3 KW - 4]0xadiazino[4 KW - 5-b]isoquinolin-1-one derivatives KW - Bicyclo[2.1.l]hexan-5-one KW - highly substituted Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58673 ER - TY - JOUR A1 - Jelinek-Fink, H. A1 - Christl, Manfred A1 - Peters, K. A1 - Peters, E.-M. A1 - Schnering, H. G. von T1 - Cycloallene, 7 : Ein Siebenringallen-Dimer: Darstellung aus einem 7,7-Dibromnorcaran-Derivat und Thermolyse T1 - Cycloallenes, 7 : A Seven-Membered-Ring Allene Dimer: Preparation from a 7,7-Dibromonorcarane Derivative and Thermolysis N2 - No abstract available KW - Organische Chemie KW - Bisbenzo[ 4 KW - 5]cyclohepta[ 1 KW - 2-α:2' KW - 1' -c]naphthalene KW - hexahydro- KW - 7-Norcaranylidene carbenoid KW - substituted KW - Cycloallene dimerization KW - Tetrakis(arylmethylene)ethane diradical KW - 1 KW - 2-Bismethylenecyclobutanes Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58603 ER - TY - JOUR A1 - Christl, Manfred A1 - Braun, Martin A1 - Wolz, E. A1 - Wagner, W. T1 - Cycloallene, 9 - 1-Phenyl-1-aza-3,4-cyclohexadien, das erste Isodihydropyridin: Erzeugung und Abfangreaktionen T1 - Cycloallenes, 9 - 1-Phenyl-1-aza-3,4-cyclohexadiene, the First Isodihydropyridine: Generation and Interception N2 - No abstract available KW - Organische Chemie KW - Isoquinolines KW - hexahydro- KW - Cyclobuta[c}pyridines KW - hexahydro- KW - Cycloadditions KW - [2 + 2]- and [4 + 2]- KW - 3-Azabicyclo{3 KW - 1 KW - 0]hexane KW - 6 KW - 6-dibromo-3-phenyl- KW - 2 KW - 4-Pentadienylamine KW - 3-n-butyl-N-phenyl- Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58714 ER - TY - JOUR A1 - Stangl, R. A1 - Jelinek-Fink, H. A1 - Christl, Manfred T1 - Darstellung phenylsubstituierter Derivate des Tricyclo[4.1.0.0\(^{2,7}\)]heptans und des 1,2,3,4-Tetrahydro-1,2,3-methenonaphthalins N2 - No abstract available KW - Organische Chemie KW - Bicyclo[3.2.0.02 KW - 7]heptane derivatives KW - Norcaranes KW - 7 KW - 7-dibromo KW - lH-Cyclopropa[a]naphthalenes KW - 1 KW - 1-dibromo-1a KW - 2 KW - 3 KW - 7b-tetrahydro- KW - Carbene insertion KW - Bicyclo[1.1.0]butane derivatives Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58610 ER - TY - JOUR A1 - Christl, Manfred A1 - Lang, R. A1 - Reimann, W. A1 - Irngartinger, H. T1 - Darstellung und Röntgenstrukturanalyse des Diels-Alder-Addukts von 4-Phenyl-4H-1,2,4-triazol-3,5-dion an Octavalen N2 - No abstract available KW - Organische Chemie Y1 - 1984 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58162 ER - TY - JOUR A1 - Christl, Manfred A1 - Freitag, G. T1 - Das Tricyclo[4.1.0.0\(^{2,7}\)]heptenyl-Kation, ein neues Isomer des Tropylium-Ions N2 - No abstract available KW - Organische Chemie Y1 - 1976 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-57985 ER - TY - JOUR A1 - Christl, Manfred A1 - Freitag, G. A1 - Brüntrup, G. T1 - Der Aufbau des Tetracyclo[4.1.0.0\(^{2,4}\).0\(^{3,5}\)]heptan-Systems durch Addition halogensubstituierter Carbene an Benzvalen N2 - No abstract available KW - Organische Chemie Y1 - 1978 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58019 ER - TY - JOUR A1 - Christl, Manfred A1 - Herbert, R. T1 - Der Einfluß anellierter Ringe auf die \(^{13}\)C-NMR-chemischen Verschiebungen von Tricyclo[3.1.0.0\(^{2,6}\)]hexan- und Bicyclo[2.1.1]hexan-Derivaten N2 - No abstract available KW - Organische Chemie Y1 - 1979 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58058 ER - TY - JOUR A1 - Christl, Manfred A1 - Brückner, D. T1 - Der Einfluß von Phenylgruppen auf die Homokonjugation im Bicyclo[3.2.1]octa-3,6-dien-2-yl-Anion. Eine \(^{13}\)C-NMR-Studie N2 - No abstract available KW - Organische Chemie Y1 - 1986 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58288 ER - TY - JOUR A1 - Engels, Bernd T1 - Detailed study of the configuration selected multi-reference configuration interaction method combined with perturbation theory to correct the wave function N2 - A reliable prediction of the isotropic hyperfine coupling constant A\(_{iso}\) is still a difficult task for ab initio calculations. In previous studies, the configuration selected multireference configuration interaction method in combination with perturbation theory to correct the wave function (MRCI/ B\(_K\)) yielded accurate isotropic hyperfine coupling constants very economically. The present study gives a detailed analysis of the MRCI/ B\(_K\) method based on the X\(^2 \pi\) state of CH as a test case. Furthermore, a comparison to various other methods such as Maller-Ptesset perturbation theory and the coupled cluster approach is made. The success of the MRCI/ B\(_K\) method in predicting isotropic hyperfine coupling constants is explained in terms of the inßuence of higher than double excitations. KW - Organische Chemie Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59019 ER - TY - JOUR A1 - Christl, Manfred A1 - Lanzendörfer, F. A1 - Peters, K. A1 - Peters, E.-M. A1 - Schnering, H. G. von T1 - Die Reaktionen von 2,5-Diaryl-1,3,4-oxadiazin-6-onen mit trans-Cycloocten, cis,trans-Cyclooctadien und Cyclopropenen N2 - The transient [4+2]-cycloadducts from the title components eliminate nitrogen to form a 3,4-dihydro-2-pyrone derivative, a tricyclic cyclobutanone derivative and 2,5-dihydrooxepin-2-one derivatives, respectively. KW - Organische Chemie Y1 - 1983 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58156 ER - TY - JOUR A1 - Hegmann, Joachim A1 - Christl, Manfred A1 - Peters, Karl A1 - Peters, Eva-Maria A1 - Schnering, Hans Georg von T1 - Die Reaktionskaskade von 6-Oxo-5-phenyl-1,3,4-oxadiazin-2-carbonsäure-methylester und 1,3-Butadienen zu konjugierten und nichtkonjugierten Cyclopentenonen N2 - Fünfgliedrige Carbocyclen sind Bauelemente zahlreicher NaturstofTe und daher attraktive Syntheseziele. Da bisher kein Syntheseverfahren mit großer Anwendungsbreite bekannt ist, sind neue Methoden willkommen. Wir berichten hier über Umsetzungen des Titelheterocyclus 1 mit l,3-Butadienen 1; diese Reaktionen, obwohl vielstufig, liefern im Eintopfverfahren konjugierte und nichtkonjugierte Cyclopentenone und gestatten auch die Fünfringanellierung. KW - Organische Chemie Y1 - 1988 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58421 ER - TY - JOUR A1 - Suter, H. U. A1 - Pleß, V. A1 - Ernzerhof, M. A1 - Engels, Bernd T1 - Difficulties in the Calculation of Electron Spin Resonance Parameters using Density Functional Methods N2 - Density functional theory is applied to the calculation ofthe isotropic byperfine coupJing constants in some small molecules. Various functionals are tested. The agreement of the calculated values to experimental data and values obtained from sophisticated ab initio methods depends on the functionals used and the system under consideration. With respect to spin density calculations the functional of Lee, Yang and Parr with Becke's excbange functional (BLYP) is found to give good results for tbe heavier center of the CH and the NH molecule, while the spin densities of other molecules such as OH, H\(_2\)CN, H\(_2\)CO\(^+\), NO and O\(_2\) deviate considerably from experimental and/or other theoretical results (30%-60%). In cases where the singly occupied orbital can contribute to the isotropic hyperfine coupling constants, accurate results are obtained. The reason fortbis is analyzed. KW - Organische Chemie Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59113 ER - TY - JOUR A1 - Christl, Manfred A1 - Brüntrup, Gisela T1 - Diimine Reduction and Ozonolysis of Benzvalene N2 - Via reduction of benzvalene (1) with diirnine tricyclo[3.1.0.02•6]hexane is obtained in good yield. The procedure renders 3, which has already been synthesized by Lemal and Shim, accessible much easier and in larger quantities. IH and 13C n.m.r. spectroscopic data are discussed. Both the thermal and the AgBF4-catalyzed rearrangernent of 3 yield 1,3-cyclohexadiene (8). - The ozonolysis of 1 with subsequent LiAIH4-reduction results in cis-I,3- bis(hydroxyrnethyl)cyclobutane (13a). N2 - Durch Reduktion von Benzvalen (1) mit Diimin wird das Tricyc1o[3.1.0.02•6]hexan (3) in guter Ausbeute erhalten. Das Verfahren macht das bereits von Lemal und Shim dargestellte 3 erheblich leichter und in größeren Mengen zugänglich. IH- und 13C-NMR-spektroskopische Daten werden diskutiert. Sowohl die thermische als auch die AgBF4-katalysierte Umlagerung von 3 führt zu 1,3-Cyclohexadien (8). - Die Ozonolyse von 1 mit anschließender LiAlH4-Reduktion ergibt das cis-l,3-Bis(hydroxymethyl)cyclobutan (13a). KW - Organische Chemie Y1 - 1974 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-57953 ER - TY - JOUR A1 - Mühlhäuser, M. A1 - Engels, Bernd A1 - Marian, C. M. A1 - Peyerimhoff, S. D. A1 - Bruna, P. J. A1 - Jansen, M. T1 - Einfluß der Ladungsverteilung auf die Bindungslängen im P\(_4\)O\(_6\) Gerüst bei Verbindungen des Typs P\(_4\)O\(_6\)X N2 - No abstract available KW - Organische Chemie Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59034 ER - TY - JOUR A1 - Christl, Manfred A1 - Lüddecke, H.-J. A1 - Nagyrevi-Neppel, A. A1 - Freitag, G. T1 - Einige Diels-Alder-Additionen des Benzvalens N2 - No abstract available KW - Organische Chemie Y1 - 1977 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-57992 ER - TY - JOUR A1 - Christl, Manfred A1 - Lechner, M. T1 - Einige Reaktionen des 8,8-Dibromtetracyclo[5.1.0.0\(^{2,4}\).0\(^{3,5}\)]octans N2 - No abstract available KW - Organische Chemie Y1 - 1982 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58108 ER - TY - JOUR A1 - Christl, Manfred A1 - Gerstner, E. A1 - Kemmer, R. A1 - Llewellyn, G. A1 - Bentley, T. W. T1 - Elektrophile Additionen an das Bicyclo[1.1.0]butan-System von 1-Phenyl- und 1-(4-Anisyl)tricyclo[4.1.0.0\(^{2,7}\)]heptan: Säure-katalysierte Reaktionen mit Wasser und Methanol, Anlagerung von Essigsäure und Oxymercurierung N2 - No abstract available KW - Organische Chemie KW - 6-Norpinanols KW - 6-aryl- KW - preparation KW - 6-Norpinyl 3 KW - 5-dinitrobenzoates KW - hydrolysis KW - Carbocations KW - generation and rearrangement KW - 2-Norcaranols KW - 1-aryl- KW - Cyclohept-3-en-1-ols KW - 3-aryl- KW - conformation Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58696 ER - TY - JOUR A1 - Gerstner, E. A1 - Kemmer, R. A1 - Christl, Manfred T1 - Elektrophile Additionen an das Bicyclo[1.1.0]butan-System von Tricyclo[4.1.0.0\(^{2,7}\)]-heptan-Derivaten: Halogen-Elektrophile T1 - Electrophilic Additions to the Bicyclo[l.l.O)butane System of Tricyclo[4.1.0.0\(^{2,7}\)]heptane Derivatives: Halogen Electrophiles N2 - No abstract available KW - Organische Chemie KW - Norpinanes KW - preparation KW - Carbocations KW - classical and nonclassical KW - Neighbouring group participation KW - Halonium ions KW - Migratory aptitudes in carbocations Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58700 ER - TY - JOUR A1 - Engels, Bernd T1 - Estimation of the influence of the configurations neglected within truncated MR-CI wavefunctions on molecular properties N2 - Reliable prediction of the isotropic hyperfine coupling constant, a\(_{iso}\), is still a difficult task for ab initio calculations. Strong dependence on the method used for its calculation is found. Within a truncated multi-referencc ansatz a\(_{iso}\) is strongly affected by the size ofthe reference space and the nurober of terms in the truncated Cl expansion. In the present paperdifferent effects of the neglected Cl space are discussed. Modified B\(_K\) and A\(_K\) methods are used to estimate the contributions ofthe neglected configurations. lt can be shown that a combination of both methods is able to recover about 90-9 S% of the total error in a\(_{iso}\)· Furthermore, it was found that to obtain about 90% of the B\(_K\) correction only about I 0-20% ofthe configurations within H0 have to be corrected. KW - Organische Chemie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58890 ER - TY - JOUR A1 - Christl, Manfred A1 - Braun, Martin T1 - Freisetzung und Abfangreaktionen von 1-Oxa-2,3-cyclohexadien T1 - Generation and Interception of 1-0xa-2,3-cyclohexadiene N2 - Umsetzung von 6,6-Dichlor-2-oxabicyclo[3.1.0)hexan (4a) in Styrol mit n-Butyllithium lieferte neben Polystyrol und t-Chlor-1- pbenylhexan (6) in geringer Ausbeute die Tet~hydrocyclobutapyrane 5, die Abfangprodukte des aus 4a generierten t-Oxa-2,3- cyclobexadiens (3). Das unbeständige 6,6-Dibrom-2-oxabicyclo( J.l.O]hexan (4b) wurde bei -60°C erzeugt un~ bei -30°C mit Methyllithium in Gegenwart von Styrol umgesetzt, woraus die Produkte 5 mit 24% Ausbeute hervorgingen. Als bei 20°C beständige Quelle für 3 erwies sich exo-6-Brom-e~o-6-fluor-2-oxabicyclo[ J.t.O]bexan (9), das aus 2,3-Dihydrofuran und Bromßuorcarben mit 25% Ausbeute bereitet wurde. Behandlung von 9 in Styrol, 95:5). Als Hauptprodukte werden für die offenkettigen Allylalkohole IIa,e,f die threo-konfigurierten Epoxyalkohole III erhalten, während die cyclischen Allylakohole IIb-d die entsprechenden cis-Epoxyalkohole III lieferen. 1,1-Dimethyl-1,2-dihydro-2-naphthol (IIc) ist hierbei eine Ausnahme, da die CH-Oxidation dieses Substrats eine beachtliche Nebenreaktion darstellt. Der Hauptunterschied zwischen den Fe- und Mn-Katalysatoren liegt in der Enantioselektivität: Während mit dem Fe(porph*)-Komplex Ia nur Selektivitäten von maximal 43 Prozent ee (krel = 2.7) erzielt werden, erwiesen sich die Mn(salen*)-Komplexe Ib,c als geeignete Katalysatoren, mit denen ee-Werte von bis zu 80 Prozent (krel = 12.9) erreicht werden. Die in der kinetischen Racematspaltung erzielten Selektivitäten können durch ein synergistisches Zusammenwirken von hydroxy-dirigierendem Effekt einerseits und sterischen Wechselwirkungen zwischen Substrat und Eisen-Komplex oder, im Falle des Mangan-Komplexes, Angriff des Olefins entlang der so genannten Katsuki-Trajektorie andererseits erklärt werden. Fazit: Die chiralen Mn(salen*)-Komplexe Ib,c sind wirkungsvolle Katalysatoren für die asymmetrische Epoxidierung racemischer sekundärer Allylalkohole II. In exzellenten Chemo- und Diastereoselektivitäten entstehen die entsprechenden Epoxyalkohole III mit ee-Werten bis zu 80 Prozent. Die zurückbleibenden Allylalkohole werden dabei bis zu 53 Prozent ee angereichert. Im Vergleich dazu weist der Eisenkomplex Ia eine ungleich geringere Enantioselektivität auf. Mechanistische Untersuchungen mit Vinylcyclopropan Va ergeben, dass die Jacobsen-Katsuki-Epoxidierung nicht über ein kationisches, sondern über ein radikalisches Intermediat abläuft. Dies wird anhand von Produktstudien durch reversed phase-HPLC-Analytik belegt. In weitergehenden Untersuchungen mit cis-Stilben (Vb) und cis--Methylstyrol (Vc) als Sonden zur cis/trans-Isomerisierung wurde festgestellt, dass die Diastereoselektivität der Epoxidierung nicht nur vom Gegenion des Mangankatalysators Ib, sondern auch von der eingesetzten Sauerstoffquelle [OxD] abhängt. Daher musste der Katalysezyklus (Schema A) um eine diastereoselektivitäts-bestimmende Gabelung erweitert werden: Das primär entstehende MnIII(OxD)-Addukt kann entweder unter Abspaltung der Fluchtgruppe zum etablierten MnV(oxo)-Komplex reagieren (Weg 1) oder direkt das Olefin epoxidieren (Weg 2). Während die Sauerstoffübertragung durch die Oxo-Spezies stufenweise über ein Radikalintermediat verläuft und damit zu einer Mischung aus cis- und trans-Epoxid führt, erfolgt der Lewisäure-aktivierte Sauerstofftransfer konzertiert. Der Gegenion-Effekt auf die cis/trans-Isomerisierung erklärt sich dahingehend, dass die Natur des Anions (koordinierend oder nicht-koordinierend) die Lebensdauer des Radikalintermediats und/oder die Lage und Selektivität der Energiehyperflächen der verschiedenen Spinzustände des MnV(oxo)-Oxidans beeinflusst. Fazit: In der Jacobsen-Katsuki-Epoxidierung existiert neben dem etablierten MnV(oxo)-Oxidans zumindest noch ein weiteres; dabei handelt es sich um das MnIII(OxD)-Addukt, dessen Sauerstoff Lewissäure-aktiviert übertragen wird. Ein unterschiedlicher Anteil der beiden Reaktionskanäle erklärt die Unterschiede im Ausmaß der cis/trans-Isomerisierung. Auch das Gegenion des Mangan-Komplexes Ib beeinflusst die cis/trans-Diastereoselektivität. Mit koordinierenden Gegenionen dominiert Isomerisierung zum trans-Epoxid, während nicht-koordinierende Gegenionen bevorzugt zum cis-Epoxid führen. N2 - The aim of the present work was to explore the potential of chiral iron(porphyrin) and manganese(salen) complexes for the kinetic resolution of secondary allylic alcohols by asymmetric epoxidation. Furthermore, the mechanism of the Jacobsen-Katsuki epoxidation was investigated by elucidating the factors that determine the cis/trans diastereoselectivity in the epoxidation of cis olefins. A set of aryl-substituted racemic allylic alcohols IIa-f has been oxidized by the catalysts Ia and Ib,c with 0.8 or 0.6 equiv. of iodosyl benzene as oxygen source (eq. I) to effect kinetic resolution. For both catalysts, the oxidation is chemoselective (predominantly epoxidation) as well as diastereoselective (dr up to > 95:5), to afford the threo- or cis-configured epoxy alcohols III as main products. In this kinetic resolution, one enantiomer of the allylic alcohol II is preferentially epoxidized to give the corresponding epoxy alcohol III in ee values up to 80 per cent, the other enantiomer remains unreacted and is enriched (up to 53 per cent ee). Quite exceptional is 1,1-dimethyl-1,2-dihydro-2-naphthol (IIc), for which the CH oxidation dominates. The main difference between the iron and the manganese catalysts concerns their enantioselectivity: Whereas the Fe(porph*) complex Ia exhibits only moderate ee values of up to 43 per cent (krel up to 2.7), the Mn(salen*) complexes Ib,c provide enantioselectivities of up to 80 per cent ee (krel up to 12.9), which makes them useful catalysts for the kinetic resolution of the allylic alcohols II. The appreciable selectivities displayed for the manganese complexes Ib,c in these asymmetric epoxidations may be rationalized in terms of the synergistic interplay between the hydroxy-directing effect and the interactions of the catalyst and the substrate in the attack of the olefin along the Katsuki trajectory. Conclusion: The chiral Mn(salen*) complexes Ib,c are highly effective catalysts for the asymmetric epoxidation of the racemic allylic alcohols II. The respective epoxy alcohols III are formed in excellent chemo- and diastereoselectivitites with ee values up to 80 per cent, while the unreacted allylic alcohols are enriched up to 53 per cent ee. In comparison, the enantioselectivity for the iron catalyst Ia is much lower. The manganese-catalyzed oxidation of vinylcyclopropane Va reveals that radical intermediates are formed in the Jacobsen-Katsuki epoxidation rather than cationic ones, as has been confirmed through product studies by reversed-phase HPLC analysis. With cis-stilbene (Vb) and cis--methyl styrene (Vc) as mechanistic probes, it has been shown that the cis/trans diastereoselectivity of the Mn(salen)-catalyzed epoxidation depends not only on the counterion of the catalyst Ib, but also on the oxygen donor [OxD]. A diastereoselectivity-controlling bifurcation step needs to be added to the catalytic cycle (Scheme A), in which the initial MnIII(OxD) adduct may either split off its leaving group to form the established MnV(oxo) species (path 1) or epoxidize the olefin directly (path 2). The oxygen transfer by the oxo complex occurs stepwise through a radical intermediate and results in a mixture of the cis and trans epoxides; in contrast, the Lewis-acid-activated epoxidation is concerted. The effect of the counterion on the cis/trans diastereoselectivity may be explained in terms of whether the anion ligates to the metal. This affects the lifetime of the radical intermediate and/or the reaction profiles of the singlet, triplet and quintet spin states of the MnV(oxo) species, which in turn control the stereoselectivity. Conclusion: In addition to the established MnV(oxo) oxidant, at least one other oxidant has to be involved in the Jacobsen-Katsuki epoxidation; this species is proposed to be the MnIII(OxD) adduct that transfers its oxygen atom in a Lewis-acid activation. Varying proportions of the two oxygen-transfer pathways account for the cis/trans diastereoselectivities observed with the various oxygen donors. The cis/trans ratio also depends on the counterion of the manganese catalyst Ib: Whereas ligating counterions result in extensive cis/trans isomerization, with non-ligating counterions the formation of cis epoxides is strongly favored. KW - Mangan KW - Eisen KW - Epoxidation KW - Enantioselektivität KW - Katalyse KW - Allylalkohol KW - Organische Chemie KW - Katalyse KW - Epoxidierung KW - Mangan KW - Eisen KW - Allylalkohole KW - organic chemistry KW - catalysis KW - epoxidation KW - manganese KW - iron KW - allylic alcohols Y1 - 2002 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-1182584 ER - TY - JOUR A1 - Christl, Manfred A1 - Herzog, C. A1 - Brückner, D. A1 - Lang, R. T1 - Neue Homobenzvalen-Derivate (Tricylo[4.1.0.0\(^{2,7}\)]hept-3-ene) N2 - No abstract available KW - Organische Chemie Y1 - 1986 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58241 ER - TY - JOUR A1 - Christl, Manfred A1 - Brunn, E. A1 - Kraft, A. A1 - Irngartinger, H. A1 - Huber-Patz, U. T1 - Nichtbindende Wechselwirkungen in zwei 7-Spirotetracyclo[4.1.0.0\(^{2,4}\).0\(^{3,5}\)]heptanen T1 - Nonbonded Interactions in two 7-Spirotetracyclo[4.1.0.0\(^{2,4}\).0\(^{3,5}\)]beptanes N2 - Die Reaktion von Tetrachlordiazocyclopentadien mit Be.nzvalen (2) ergab das Fulven-Derivat 3. Dagegen führten die Umsetzungen von Diazoßuoren und 5-Diazo-10,1 1-dihydro-SH-dibenzo[ a.d]cyclohepten mit 2 zu den erwarteten Spiro-1-pyrazolinen 4 bzw. 5. Die photolytische Abspaltung von Stickstoff aus 4 und 5 lieferte die Spirotetracycloheptane 6 bzw. 7. Die Röntgenstrukturanalyse von 6 beweist einen engen Kontakt zwischen je eineßl Wasserstoffatom der Tetracycloheptan- und der Fluoren-Einheit. Dieser kurze Abstand (2.15 A) ruft Winkelaufweitungen hervor und wird auch als Grund für starke Entschirmungen der betreffenden Protonen und eine formal über sieben Bindungen reichende 0.6-Hz-Kopplung zwischen ihnen angesehen. 7 ist das erste chiralc Tetracyclohcptan. Ursache dafür ist eine nichtebene Konformation des Siebenrings, der bei Raumtemperatur nicht invertiert. Auf der Basis von NOE-Messungen gelang die Zuordnung der tH-NMR-Signale von 6 und 7. N2 - The reaction or tctrachlorodiazocyclopentadiene with benzvalene (2) gavc, the fulvene derivative 3. In contrast, treatment of diazoßuorene and 5-diazo-1 0,1 1-dihydro·SH -dibenzo[ a,d]cycloheptene with l:afl'orded the expected spiro-1-pyrazolines 4 and 5, respectively. Photolytic extrusion of nitrogen from 4 and S led to the corresponding spirotetracyclobeptanes 6 and 7. The X-ray structure analysis of 6 revealed a close contact between one hydrogen atom cach of the tetracycloheptane and the ßuorene subunits. This short distance (2.15 A) causes an increase in bond angles and is believed to produce strong deshielding of the respective protons and a 0.6-Hz coupling between them, which is formally a long-range coupling across seven bonds. Compound 7 is the first chirat tetracycloheptane. This is due to a nonplanar confonnation of the seven-membered ring, which does not invert at room temperature. On tbe basis of NOE measurements the 1H-NMR signals of 6 and 7 are assigned. KW - Organische Chemie KW - 5H-Dibenzo[a KW - d]cycloheptene KW - 10 KW - 11-dihydro- / 1-Pyrazoline KW - Nonbonded Interactions KW - Spirotetracyclo[4.1.0.02 KW - 4.03 KW - 5]beptanes KW - Long-range coupling constants KW - mtrogen extruston Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58489 ER - TY - JOUR A1 - Herzog, C. A1 - Lang, R. A1 - Brückner, D. A1 - Kemmer, P. A1 - Christl, Manfred T1 - Norpinene (Bicyclo[3.1.1]hept-2-ene) aus Homobenzvalenen (Tricyclo[4.1.0.0\(^{2,7}\)]hept-3-enen) N2 - No abstract available KW - Organische Chemie Y1 - 1986 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58302 ER - TY - JOUR A1 - Christl, Manfred A1 - Roberts, J. D. T1 - Nuclear Magnetic Resonance Spectroscopy : Carbon-13 Chemical Shifts of Small Peptides as a Function of pH N2 - No abstract available KW - Organische Chemie Y1 - 1972 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-57885 ER - TY - JOUR A1 - Christl, Manfred A1 - Reich, H. J. A1 - Roberts, J. D. T1 - Nuclear Magnetic Resonance Spectroscopy. Carbon-13 Chemical Shifts of Methylcyclopentanes, Cyclopentanols, and Cyclopentyl Acetates N2 - No abstract available KW - Organische Chemie Y1 - 1971 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-57862 ER - TY - JOUR A1 - Christl, Manfred A1 - Türk, M. A1 - Peters, K. A1 - Peters, E.-M. A1 - Schnering, H. G. von T1 - Octahydro-1,2,3:4,5,6-dimethenopentalen-2-carbonitril, das erste Derivat eines noch unbekannten (CH)\(_{10}\)-Kohlenwasserstoffs N2 - No abstract available KW - Organische Chemie Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58728 ER - TY - JOUR A1 - Christl, Manfred A1 - Türk, M. A1 - Peters, K. A1 - Peters, E.-M. A1 - Schnering, H. G. von T1 - Octahydro-1,2,3:4,5,6-dimethenopentalene-2-carbonitrile, the First Derivative of a Yet-Unknown (CH)\(_{10}\)-Hydrocarbon N2 - No abstract available KW - Organische Chemie Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58731 ER - TY - JOUR A1 - Metropoulos, B. A1 - Engels, Bernd A1 - Peyerimhoff, S.D. T1 - On the chemi-ionization reaction O + CH ----> HCO\(^+\)+ e\(^-\). Coollinear O-CH Approach N2 - We have investigated theoretically the importance of the O(\(^3\)P)+CH(a\(^4\sum^-\)) and the O(\(^3\)P)+CH(X\(^2\Pi\)) channels in the collinear chemi-ionization reaction O+CH->HCO\(^+\) +e\(^-\). We have found that both channels may lead to chemi-ionization via favorable Franck-Condon overlaps with the states ofthe ionic species. KW - Organische Chemie Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58963 ER - TY - THES A1 - Gsänger, Marcel T1 - Organic Thin-Film Transistors Based on Dipolar Squaraine Dyes T1 - Organische Dünnschichttransistoren von dipolaren Squarainfarbstoffen N2 - In summary, it can be stated that the herein studied set of acceptor-substituted squaraine dyes can be seen as potent candidates for OTFTs. Furthermore, their transistor performance can be easily tuned to obtain hole mobilities up to 0.45 cm2/Vs from solution and 1.3 cm2/Vs from sublimation by choosing adequate deposition techniques. In the end, a probable structural model derived from studies of the thin-film morphology by methods such as optical spectroscopy, AFM and X-ray even facilitated the clarification of the observed charge transport behavior. N2 - Zusammenfassend lässt sich sagen, dass die in dieser Arbeit untersuchten akzeptorsubstituierten Squarainfarbstoffe durchaus als leistungsfähige Kandidaten für den Einsatz in OTFT-Bauteilen angesehen werden können. Ihre Transistorleistung lässt sich durch geeignete Wahl der Abscheidungsmethode dahingehend einstellen, als dass sich Lochmobilitäten von bis zu 0.45 cm2/Vs mittels Lösungsprozessierung und von bis zu 1.3 cm2/Vs mittels Sublimation realisieren lassen. Schließlich ermöglichte die Untersuchung der Dünnfilmmorphologie mit Methoden wie der optischen Spektroskopie, Rasterkraftmikroskopie und Röntgenbeugung die Schlussfolgerung auf ein mutmaßliches Strukturmodell. KW - Organische Chemie KW - Squaraine KW - Organischer Feldeffekttransistor KW - Organic Chemistry KW - Squaraine KW - Organic Field-Effect Transistor KW - Organischer Halbleiter Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-80588 ER - TY - JOUR A1 - Christl, Manfred A1 - Huisgen, R. T1 - Orientierungsphänomene bei der Cycloaddition aliphatischer und aromatischer Nitriloxide an α,β-ungesättigte Carbonester N2 - No abstract available KW - Organische Chemie Y1 - 1973 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-57942 ER - TY - JOUR A1 - Leininger, H. A1 - Christl, Manfred T1 - Oxidationsreaktionen am Benzvalen: Ozonolyse, cis-Hydroxylierung, Epoxidation und Singulettsauerstoff-Addition N2 - No abstract available KW - Organische Chemie Y1 - 1980 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58088 ER - TY - THES A1 - Sapotta, Meike T1 - Perylene Bisimide Cyclophanes: Recognition of Alkaloids, Aggregation Behavior in Aqueous Environment and Guest-Mediated Chirality Transfer T1 - Perylenbisimidcyclophane: Alkaloiderkennung, Aggregationsverhalten in wässriger Umgebung und gastvermittelter Chiralitätstransfer N2 - Inspired by the fact that sufficient solubility in aqueous media can be achieved by functional substitution of perylene bisimides (PBIs) with polar groups, one of the essential aims of this thesis was the design and successful synthesis of the new water-soluble PBI cyclophanes [2PBI]-1m and [2PBI]-1p, which are appended with branched, hydrophilic oligoethylene glycol (OEG) chains. Subsequently, the focus was set on the elucidation of properties of PBI cyclophane hosts which are also of relevance for recognition processes in biological systems. The performance of the new amphiphilic PBI cyclophane [2PBI]-1p as synthetic receptors for various natural aromatic alkaloids in aqueous media was thoroughly investigated. Alkaloids represent a prominent class of ubiquitous nitrogen containing natural compounds with a great structural variety and diverse biological activity. As of yet, no chromophore host acting as a molecular probe for a range of alkaloids such as harmine or harmaline is known. In addition, the self-association behavior of cyclophane host [2PBI]-1m and its reference monomer in water was studied in order to gain insights into the thermodynamic driving forces affecting the self-assembly process of these two PBI systems in aqueous environment. Moreover, the chirality transfer upon guest binding previously observed for a PBI cyclophane was investigated further. The assignment of the underlying mechanism of guest recognition to either the induced fit or conformational selection model was of particular interest. N2 - Diese Arbeit befasste sich mit der Erforschung neuer Eigenschaften von Perylenbisimid-cyclophanwirten, zum Beispiel der Gast-Komplexierung in wässriger Umgebung (Kapitel 3.2) oder dem Einfluss von Wasser beim Selbstassemblierungsprozess einer dieser Wirte in Wasser (Kapitel 3.3). Weiterhin wurden der Chiralitätstransfer durch Gasterkennung und das der Wirt-Gast-Komplexbildung zugrunde liegende mechanistische Modell untersucht (Kapitel 3.4). ... KW - Supramolekulare Chemie KW - Perylenderivate KW - Wirt-Gast-Beziehung KW - Host-Guest-Chemistry KW - Self-Assembly in Water KW - Chirality Transfer KW - Chiralität KW - Selbstorganisation KW - Organische Chemie Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200028 ER - TY - JOUR A1 - Christl, Manfred A1 - Braun, Max T1 - Photocycloadditionen des Benzvalens N2 - No abstract available KW - Organische Chemie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58492 ER - TY - JOUR A1 - Christl, Manfred A1 - Braun, Max T1 - Photocycloadditions of Benzvalene N2 - No abstract available KW - Organische Chemie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58506 ER - TY - THES A1 - Mahl, Magnus T1 - Polycyclic Aromatic Dicarboximides as NIR Chromophores, Solid-State Emitters and Supramolecular Host Platforms T1 - Polyzyklische aromatische Dicarboximide als NIR-Chromophore, Festkörperemitter und supramolekulare Wirtsplattformen N2 - The present thesis introduce different synthetic strategies towards a variety of polycyclic aromatic dicarboximides (PADIs) with highly interesting and diverse properties. This included tetrachlorinated, tetraaryloxy- and tetraaryl-substituted dicarboximides, fused acceptor‒donor(‒acceptor) structures as well as sterically shielded rylene and nanographene dicarboximides. The properties and thus the disclosure of structure‒property relationships of the resulting dyes were investigated in detail among others with UV‒vis absorption spectroscopy, fluorescence spectroscopy, cyclic voltammetry and single crystal X-ray analysis. For instance, some of the fused and substituted PADIs offer strong absorption of visible and near infrared (NIR) light, NIR emission and low-lying LUMO levels. On the contrary, intriguing optical features in the solid-state characterize the rylene dicarboximides with their bulky N-substituents, while the devised sterically enwrapped nanographene host offered remarkable complexation capabilities in solution. N2 - Die vorliegende Arbeit stellt verschiedene Synthesestrategien für eine Vielfalt an polyzyklischen aromatischen Dicarboximiden (PADIs) mit hochinteressanten und vielfältigen Eigenschaften vor. Dies beinhaltete tetrachlorierte, tetraryloxy- und tetraaryl-substituierte Dicarboximide, fusionierte Akzeptor‒Donor(‒Akzeptor)-Strukturen wie auch sterisch abgeschirmte Rylen- und Nanographen-Dicarboximide. Die Eigenschaften und damit die Offenlegung von Struktur‒Eigenschaftsbeziehungen der resultierenden Farbstoffe wurden unter anderem mittels UV‒vis Absorptionsspektroskopie, Fluoreszenzspektroskopie, Zyklovoltammetrie und Einkristallstrukturanalyse detalliert untersucht. Zum Beispiel bieten einige der fusionierten und substituierten PADIs eine starke Absorption von sichtbaren und nahen Infrarot-Licht (NIR), NIR-Emission und niedrigliegende LUMO-Niveaus. Im Gegensatz dazu sind die Rylendicarboximide mit ihren voluminösen N-Substituenten durch faszinierende optische Eigenschaften im Festkörper charakterisiert, wohingegen der konzipierte sterisch eingehüllte Nanographen-Wirt bemerkenswerte Komplexierungs-Fähigkeiten in Lösung zeigte. KW - Organische Chemie KW - Perylenbisdicarboximide KW - Farbstoff KW - Fluoreszenz KW - Supramolekulare Chemie KW - C-C coupling KW - dicarboximide KW - NIR chromophore KW - solid-state emitter KW - host-guest chemistry Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-234623 ER - TY - JOUR A1 - Christl, Manfred A1 - Lanzendörfer, U. A1 - Grötsch, M. M. A1 - Hegmann, J. T1 - Primäraddukt, γ-Ketoketen und einige Folgeprodukte der Reaktion von 6-Oxo-5-phenyl-1,3,4-oxadiazin-2-carbonsäure-methylester mit Norbornen N2 - No abstract available KW - Organische Chemie Y1 - 1985 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58220 ER - TY - JOUR A1 - Huisgen, R. A1 - Christl, Manfred T1 - Reaktionen der Knallsäure mit ungesättigten Verbindungen N2 - No abstract available KW - Organische Chemie Y1 - 1973 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-57927 ER - TY - JOUR A1 - Reuchlein, H. A1 - Kraft, A. A1 - Christl, Manfred A1 - Peters, K. A1 - Peters, E.-M. A1 - Schnering, H. G. von T1 - Reaktionen von Bicyclo[2.1.1]hexenen mit 1,3,4-Oxadiazin-6-onen und dynamische Effekte einem in neungliedrigen, überbrückten, α,β-ungesättigten Enollacton N2 - No abstract available KW - Organische Chemie KW - 1 KW - 3 KW - 4-0xadiazin-6-ones KW - Diels-Alder reactions KW - Enol Iactones KW - Lactone conformations KW - Line-shape analysis Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58577 ER - TY - JOUR A1 - Lang, R. A1 - Herzog, C. A1 - Stangl, R. A1 - Brunn, E. A1 - Braun, M. A1 - Christl, Manfred A1 - Peters, K. A1 - Peters, E.-M. A1 - Schnering, H. G. von T1 - Reaktionen von Homobenzvalenen mit 4-Phenyl-3H-1,2,4-triazol-3,5(4H)-dion, Tetracyanethylen, Chlorsulfonylisocyanat und Schwefeldioxid. Einige konzertierte 1,4-Additionen an eine Vinylcyclopropan-Einheit T1 - Reactions of Homobenzvalenes wlth 4-Phenyl-3H-1,2,4-trlazole-3,5(4H)-dione, Tetracyanoethylene, Chlorosulfonyl Isocyanate, and Sulfur Dioxide. Several Concerted 1,4-Additions to a Vinylcyclopropane Subunit N2 - No abstract available KW - Organische Chemie KW - 6-Thiatricyclo[3.2.1.o 2.7 ]oct-3-ene 6 KW - 6-dioxide KW - Homo Diels-Alder reactions KW - Cyclopropanetetracarbonitrile derivatives KW - Barbaralane derivatives KW - Urazoles KW - polycyclic Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58527 ER - TY - JOUR A1 - Korth, H.-G. A1 - Müller, W. A1 - Sustmann, R. A1 - Christl, Manfred T1 - Rearrangement of Free Radicals, XII. ESR Spectroscopic Study of the Ring Opening of the Homobenzvalenyl Radical N2 - Abstraction of an allylic hydrogen atom in homobenzvalene (4) either in solurion by photolyticaßy generated tert-butoxyl radicals or in an adamantane matrix by X-rays produces the homobcnzvalenyl radical (5). which tbennally rearranps · to tbe tropylium ndical (1). In solution tbe activation cnergy for the rate determined step of the reaction sequence was detennined· to be 13.4 ± O.S kcal/mol. KW - Organische Chemie Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58376 ER - TY - JOUR A1 - Bast, K. A1 - Christl, Manfred A1 - Huisgen, R. A1 - Mack, W. T1 - Relative Dipolarophilen-Aktivitäten bei Cycloadditionen des Benzonitriloxids N2 - No abstract available KW - Organische Chemie Y1 - 1973 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-57935 ER - TY - JOUR A1 - Pratihar, Pampa A1 - Ghosh, Suhrit A1 - Stepanenko, Vladimir A1 - Patwardhan, Sameer A1 - Grozema, Ferdinand C. A1 - Siebbeles, Laurens D. A. A1 - Würthner, Frank T1 - Self-assembly and semiconductivity of an oligothiophene supergelator N2 - A bis(trialkoxybenzamide)-functionalized quaterthiophene derivative was synthesized and its self-assembly properties in solution were studied. In non-polar solvents such as cyclohexane, this quaterthiophene π-system formed fibril aggregates with an H-type molecular arrangement due to synergistic effect of hydrogen bonding and π-stacking. The self-assembled fibres were found to gelate numerous organic solvents of diverse polarity. The charge transport ability of such elongated fibres of quaterthiophene π-system was explored by the pulse radiolysis time resolved microwave conductivity (PR-TRMC) technique and moderate mobility values were obtained. Furthermore, initial AFM and UV-vis spectroscopic studies of a mixture of our electron-rich quaterthiophene derivative with the electron acceptor [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) revealed a nanoscale segregated assembly of the individual building blocks in the blend. KW - Organische Chemie KW - charge transport; hydrogen bonding; oligothiophene; organogel; self-assembly Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-67817 ER - TY - JOUR A1 - Christl, Manfred A1 - Freund, S. A1 - Henneberger, H. A1 - Kraft, A. A1 - Hauck, J. A1 - Irngartinger, H. T1 - Several Polycyclic Valence Isomers of Dimethyl [14]Annulene-1,8-dicarboxylate. Reactivity of a "Nonconjugated" Bis(bicyclo[1.1.0]butane) N2 - Diels-Alder reaction of dimethyl 1,2,4,5-tetrazine-3,6-dicarboxylate (5) with benzvalene (4), norbornene, and norbornadiene afforded the azo compounds 7 and 8. Theseare derivatives of 2,3-diazabicyclo[2.2.2]oct-2-ene as is azo compound 3, which had been obtained previously from 5 and 2 equiv of benzvalene (4). The photochemical extrusion of nitrogen from 3, 7, and 8 has been studied. Whereas 7 and 8 on direct irradiation in benzene gave rise exclusively to the bicyclo[2.2.0]hexane derivatives 9 and 10, respectively, from 3 in addition to the bicyclo[2.2.0]hexane 11, the diolefin 1l was formed. Diolefin 12 has cisdouble bonds in the nine-membered ring and is fixed in a boat conformation in a manner so that the two bicyclobutane systems approach each other very closely. This geometry suggests the unusual ring opening of the intermediate 1,4-cyclohexanediyl diradical from a boat conformation, which arises by inversion of the primarily generated boat conformation. Sensitized photolysis of 3 as weilasthat of ll produced the saturated isomer 13 of 11 and 12. The proximity of the bicyclobutane systems in 1l causes unprecedented reactions leading to cage compounds. When ll was heated at 90 °C, a rearrangement to the pentacyclic product 10 took place. Utilization of tetradeuteriated substrate ll-d4 supported a pathway with two diradical intermediates. Behaving in a convcntional manncr, bicyclobutane 9 and bis(bicyclobutane) 11 took up 1 and 2 equiv of thiophenol most probably in a radical-chain addition to give the thioethers 28 and 19, respectively. In contrast, bis(bicyclobutane) ll was converted by 1 equiv of thiophenol into cagc compound 30 in a process involving both the strained a systems. Heating at 80 °C subjected 30 to a reversible Copc rearrangement, resulting in a 6:1 mixture of 31 and 30. When it was treated with bromine, 11 was transformed to cage compound 38. This addition is believed to proceed via a cationic intermediate. The structure of cage compound 10 was established by a singlc-crystal X-ray analysis of dialcohol 11 prepared from 20 and methyllithium. KW - Organische Chemie Y1 - 1988 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58413 ER - TY - JOUR A1 - Bentley, T. W. A1 - Norman, S. J. A1 - Gerstner, E. A1 - Kemmer, R. A1 - Christl, Manfred T1 - Solvolysis of Tricyclo[3.1.0.0\(^{2,6}\)]hex-3-yl and Bicyclo[2.1.1]hex-2-yl Sulfonates N2 - No abstract available KW - Organische Chemie KW - Bicyclo[1.1.0]butylcarbinyl sulfonates KW - solvolysis of KW - Cyclobutylcarbinyl sulfonates KW - Anchimeric assistance in solvolysis KW - Rearrangement of carbocations KW - Electron demand in ditosylates Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58689 ER - TY - JOUR A1 - Volz, H. A1 - Shin, J.-H. A1 - Prinzbach, H. A1 - Babsch, H. A1 - Christl, Manfred T1 - Stability of Tricyclo[4.1.0.0\(^{2,7}\)]heptenyl-Cations N2 - No abstract available KW - Organische Chemie Y1 - 1978 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58001 ER - TY - JOUR A1 - Markgraf, J. H. A1 - Cort, J. R. A1 - Davis, H. A. A1 - Lindeman, N. I. A1 - Myers, C. R. A1 - Kraft, A. A1 - Christl, Manfred T1 - Strained Heterocyclic Systems. 20. Basicities of Bicyclic Quinoxalines N2 - No abstract available KW - Organische Chemie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58584 ER - TY - JOUR A1 - Engels, Bernd T1 - Study of influences of various excitation classes on ab initio calculated isotropic hyperfine coupling constants N2 - Reliable prediction of the isotropic hyperfine coupling constant A\(_{iso}\) is still a difficult task for ab initio calculations. Strang dependence on the method employed for its ca1culation has been found. Within a CI ansatz A\(_{iso}\) is considerably affected by the excitation classes taken into account within the CI calculation. In the present work the influence of various excitation classes on A\(_{iso}\) is examined. Calculations including all single, double, triple and a large part of the quadruple excitations are performed and the individual effects of the excitation classes are studied. It is found that the surprisingly good agreement found for S-CI treatments is due to large error cancellations. The importance of higher than double excitations arises from their indirect influence on the single excitations. KW - Organische Chemie KW - Spin density KW - Hyperfine coupling constants KW - Influence of excitation classes KW - Indirect and direct contributions to Aiso Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58973 ER - TY - JOUR A1 - Engels, Bernd A1 - Peyerimhoff, S.D. T1 - Study of orbital transformations in configurational interaction calculation of hyperfine coupling in nitrogen and CH molecule N2 - Multi-reference configuration interaction calculations employing various orbital transformations are undertaken to obtain the isotropic hyperfine coupling constant a\(_{iso\) in nitrogen and a\(_{iso\) (H) in the CH molecule. The natural orbital (NO) basis is found to be more effective than the simple RHF-MO basis; the most obvious is a basis of spin natural orbitals (SNO). It is found that a\(_{iso\) is approached from opposite sides in the NO and 2s shell SNO basis if the CI expansion is increased. Both results are within a few percent of the full CI Iimit for the nitrogen atorn (in the given AO basis) and the experimental value for Hin the CH radical. Various features ofthe SNO are discussed. KW - Organische Chemie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58847 ER - TY - JOUR A1 - Engels, Bernd A1 - Peyerimhoff, S.D. T1 - Study of the 1s and 2s shell contributions to the isotropic hyperfine coupling constant in nitrogen N2 - The istropic part of the hyperfine coupling constant is investigated by means of multireference configuration interaction calculations employing Gaussian basis sets. A detailed study of the 1s and 2s spin polarisation in the nitrogen atom and the NH molecule shows that the structure of the lower-energy space of the unoccupied orbitals is essential for the results. A contraction of the Gaussian basis is possible without loss of accuracy if enough flexibility is retained to describe the main features of the original space of unoccupied functions. Higher than double excitations are found to be non-negligible for the description of α\(_{iso}\). KW - Organische Chemie Y1 - 1988 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58793 ER - TY - JOUR A1 - Engels, Bernd A1 - Peric, M. A1 - Reuter, W. A1 - Peyerimhoff, S.D. A1 - Grein, F. T1 - Study of the hyperfine coupling constants \(^{14}\)N and \(^1\)H) of the NH\(_2\) molecule in the X\(^2\)B\(_1\) ground state and the A\(^2\)A\(_1\) excited state N2 - The hyperfine coupling constants (hfcc) A\(_{iso}\) and A\(_{ij}\) are calculated for the atoms of NH\(_2\) in its, two lowest-lying electronk states at various molecular geometries by means of the ab initio multireference configuration interaction .method. The vibronically averaged values of the hfccs for the K = 0 and 1 levels in \(^{14}\)N \(^1\)H\(_2\) in the energy range up to 20 000 cm\(^{-1}\) are computed. Polarization elfects which determine A\(_{iso}\) as well as a simple model to describe the dipolar hfccs are discussed. All resrilts are in excellent agreement with experimental data. KW - Organische Chemie Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58937 ER - TY - JOUR A1 - Funken, K. A1 - Engels, Bernd A1 - Peyerimhoff, S.D. A1 - Grein, F. T1 - Study of the hyperfine coupling constants of the moleculs NH2, NHD and ND2 N2 - In the present paper we c:alculate tbe magnetic hyperfine couplina constants (hfcc) ai.ID and A11 of the ground states of the isotopes NH2, NHD and ND2 using truncated MR..CI methods. Differences from other theoretical methocls and shortoominp of the truncated Cl approach in calculating tlj10 are studied. Polarization effects wbich detennirae ailo. as weU as a simple model to describe the dipolar hfcc's, are discussed. All results are in. excellent aareement with experimental data. lt is shown that ab initio methods are able to obtain reliable values for otf-diaaonal values of A41 which are difficult to measure experimentaDy. KW - Organische Chemie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58875 ER - TY - JOUR A1 - Christl, Manfred A1 - Freund, S. T1 - Substituierte Benzobenzvalene und Diazabenzobenzvalene - Synthesen aus Diels-Alder-Addukten des Benzvalens und NMR-Spektroskopie N2 - No abstract available KW - Organische Chemie Y1 - 1985 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58183 ER - TY - THES A1 - Wagner, Wolfgang T1 - Supramolecular Block Copolymers by Seeded Living Supramolecular Polymerization of Perylene Bisimides T1 - Supramolekulare Blockcopolymere von Perylenbisimiden mittels saat-induzierter lebender supramolekularer Polymerisation N2 - The research on supramolecular polymerization has undergone a rapid development in the last two decades, particularly since supramolecular polymers exhibit a broad variety of functionalities and applications in organic electronics, biological science or as functional materials (Chapter 2.1). Although former studies have focused on investigation of the thermodynamics of supramolecular polymerization (Chapter 2.2), the academic interest in the recent years shifted towards gaining insight into kinetically controlled self-assembly and pathway complexity to generate novel out-of-equilibrium architectures with interesting nanostructures and features (Chapter 2.3). Along this path, the concepts of seeded and living supramolecular polymerization were recently developed to enable the formation of supramolecular polymers with controlled length and low polydispersity under precise kinetic control (Chapter 2.4). Besides that, novel strategies were developed to achieve supramolecular copolymerization resulting in complex multicomponent nanostructures with different structural motives. The classification of these supramolecular copolymers on the basis of literature examples and an overview of previously reported principles to create such supramolecular architectures are provided in Chapter 2.5. The aim of the thesis was the non-covalent synthesis of highly desirable supramolecular block copolymers by the approach of living seeded supramolecular polymerization and to study the impact of the molecular shape of the monomeric building blocks on the supramolecular copolymerization. Based on the structure of the previously investigated PBI organogelator H-PBI a series of novel PBIs, bearing identical hydrogen-bonding amide side-groups in imide-position and various kind or number of substituents in bay-position, was synthesized and analyzed within this thesis. The new PBIs were successfully obtained in three steps starting from the respective bromo-substituted perylene-3,4:9,10-tetracarboxylic acid tetrabutylesters or from the N,N’-dicyclohexyl-1,7-dibromoperylene-3,4:9,10-tetracarboxylic acid bisimide. All target compounds were obtained in the final step by imidization reactions of the respective perylene tetracarboxylic acid bisanhydride precursors with N-(2-aminoethyl)-3,4,5-tris(dodecyloxy)-benzamide and were fully characterized by 1H and 13C NMR spectroscopy as well as high resolution mass spectrometry. The variation of bay-substituents strongly changes the optical properties of the monomeric PBIs which were investigated by UV/vis and fluorescence spectroscopy. The increase of the number of the methoxy-substituents provokes, for example, a red-shift of the absorption maxima concomitant with a decrease of extinction coefficients and leads to a drastic increase of the fluorescence quantum yields. Furthermore, the molecular geometry of the PBIs is also affected by variations of the bay-substituents. Thus, increasing the steric demand of the bay-substituents leads to an enlargement of the twist angles of the PBI cores as revealed by DFT calculations. Especially the 1,7-dimethoxy bay-substituted MeO-PBI proved to be very well-suited for the studies envisioned within this thesis. The self-assembly of this PBI derivative was analyzed in detail by UV/vis, fluorescence and FT-IR spectroscopy as well as atomic force microscopy (Chapter 3). These studies revealed that MeO-PBI forms in a solvent mixture of methylcyclohexane and toluene (2:1, v/v) kinetically trapped off-pathway H-aggregated nanoparticles upon fast cooling of a monomeric solution from 90 to 20 °C. However, upon slow cooling of the monomer solution fluorescent J-type nanofibers are formed by π π interactions and intermolecular hydrogen-bonding. The kinetically metastable off-pathway H-aggregates can be transformed into the thermodynamically more favored J-type aggregates by addition of seeds, which are produced by ultrasonication of the polymeric nanofibers. Interestingly, the living character of this seed-induced supramolecular polymerization process was proven by a newly designed multicycle polymerization experimental protocol. This living polymerization experiment clearly proves, that the polymerization can only occur at the “active” ends of the polymeric seed and that almost no recombination or chain termination processes are present. Hence, the approach of living supramolecular polymerization enables the formation of supramolecular polymers with controlled length and narrow polydispersity. In Chapter 4 the copolymerization of MeO-PBI with the structurally similar 1,7-dichloro (Cl-PBI) and 1,7-dimethylthio (MeS-PBI) bay-substituted PBIs is studied in detail. Both PBIs form analogous to MeO-PBI kinetically trapped off-pathway aggregates, which can be converted into the thermodynamically stable supramolecular polymers by seed-induced living supramolecular polymerization under precise kinetic control. However, the stability of the kinetically trapped aggregates of Cl-PBI and MeS-PBI is distinctly reduced compared to that of MeO-PBI, because the π-π-interactions of the kinetically metastable aggregates are hampered through the increased twisting of the PBI-cores of the former PBIs. UV/vis studies revealed that the two-component seeded copolymerization of the kinetically trapped state of MeO-PBI with seeds of Cl-PBI leads to the formation of unprecedented supramolecular block copolymers with A-B-A pattern by a living supramolecular polymerization process at the termini of the seeds. Remarkably, the resulting A-B-A block pattern of the obtained copolymers was clearly confirmed by atomic force microscopy studies as the respective blocks formed by the individual monomeric units could be distinguished by the pitches of the helical nanofibers. Moreover, detailed UV/vis and AFM studies have shown that by inverted two-component seed-induced polymerization, e.g., upon addition of seeds of MeO-PBI to the kinetically trapped aggregates of Cl-PBI, triblock supramolecular copolymers with B-A-B pattern can be generated. The switching of the block pattern could only be achieved because of the perfectly matching conditions for the copolymerization process and the tailored molecular geometry of the individual building blocks of both PBIs. These studies have demonstrated for the first time, that the block pattern of a supramolecular copolymer can be modulated by the experimental protocol through the approach of living supramolecular polymerization. Furthermore, by UV/vis analysis of the living copolymerization of MeO-PBI and MeS-PBI similar results were obtained showing also the formation of both A-B-A and B-A-B type supramolecular block copolymers. Although for these two PBIs the individual blocks could not be identified by AFM because the helical nanofibers of both PBIs exhibit identical helical pitches, these studies revealed for the first time that the approach of seeded living polymerization is not limited to a special pair of monomeric building blocks. In the last part of the thesis (Chapter 5) a systematic study on the two-component living copolymerization of PBIs with various sterical demanding bay-substituents is provided. Thus, a series of PBIs containing identical hydrogen-bonding amide groups in imide position but variable number (1-MeO-PBI, MeO-PBI, 1,6,7-MeO-PBI, 1,6,7,12-MeO-PBI) or size (EtO-PBI, iPrO-PBI) of alkoxy bay-substituents was investigated. The molecular geometry of the monomeric building blocks has a strong impact on the thermodynamically and even more pronounced on the kinetically controlled aggregation in solvent mixtures of MCH and Tol. While the mono- and dialkoxy-substituted PBIs form kinetically metastable species, the self-assembly of the tri- and tetramethoxy-substituted PBIs (1,6,7-MeO-PBI and 1,6,7,12-MeO-PBI) is completely thermodynamically controlled. The two 1,7-alkoxy substituted PBIs (EtO-PBI, iPrO-PBI) form very similar to MeO-PBI kinetically off-pathway H-aggregates and thermodynamically more favored J-type aggregates. However, the stability of the kinetically metastable state is drastically lower and the conversion into the thermodynamically favored state much faster than for MeO-PBI. In contrast, the monomethoxy-substituted PBI derivative (1-MeO-PBI) forms a kinetically trapped species by intramolecular hydrogen-bonding of the monomers, which can be transformed into the thermodynamically favored nanofibers by seeded polymerization. Importantly, the two-component seeded copolymerization of the kinetically trapped MeO PBI with seeds of other PBIs of the present series was studied by UV/vis and AFM revealing that the formation of supramolecular block copolymers is only possible for appropriate combinations of PBI building blocks. Thus, the seeded polymerization of the trapped state of the moderately core-twisted MeO-PBI with the, according to DFT-calculations, structurally similar PBIs (EtO-PBI and iPrO-PBI) leads to the formation of A-B-A block copolymers, like in the seeded copolymerization of MeO-PBItrapped with seeds of Cl-PBI and MeS-PBI already described in Chapter 4. However, by addition of seeds of the almost planar PBIs (H-PBI and 1-MeO-PBI) or seeds of the strongly core-twisted PBIs (1,6,7-MeO-PBI and 1,6,7,12-MeO-PBI) to the kinetically trapped state of MeO-PBI no block copolymers can be obtained. The mismatching geometry of these molecular building blocks strongly hampers both the intermolecular hydrogen-bonding and the π-π-interactions between the two different PBIs and consequently prevents the copolymerization process. Furthermore, the studies of the two-component seeded copolymerization of the kinetically trapped species of 1-MeO-PBI with seeds of the other PBIs also corroborated that a precise shape complementarity is crucial to generate supramolecular block copolymers. Thus, by addition of seeds of H-PBI to the kinetically trapped monomers of 1-MeO-PBI supramolecular block copolymers were generated. Both PBIs exhibit an almost planar PBI core according to DFT-calculations leading to strong non-covalent interactions between these PBIs. This perfectly matching geometry of both PBIs also enables the inverted seeded copolymerization of the kinetically trapped monomers of H-PBI with 1-MeO-PBIseed concomitant with a switching of the block pattern of the supramolecular copolymer from A-B-A to B-A-B type. In contrast, the seeding with the moderately twisted (MeO-PBI, EtO-PBI and iPrO-PBI) and the strongly twisted PBIs (1,6,7-MeO-PBI and 1,6,7,12 MeO-PBI) has no effect on the kinetically trapped state of 1-MeO-PBI, because the copolymerization of these PBIs is prevented by the mismatching geometry of the molecular building blocks. In conclusion, the supramolecular polymerization and two-component seeded copolymerization of a series of PBI monomers was investigated within this thesis. The studies revealed that the thermodynamically and kinetically controlled self-assembly can be strongly modified by subtle changes of the monomeric building blocks. Moreover, the results have shown that living supramolecular polymerization is an exceedingly powerful method to generate unprecedented supramolecular polymeric nanostructures with controlled block pattern and length distribution. The formation of supramolecular block copolymers can only be achieved under precise kinetic control of the polymerization process and is strongly governed by the shape complementarity already imparted in the individual components. Thus, these insightful studies might enable a more rational design of monomeric building blocks for the non-covalent synthesis of highly complex supramolecular architectures with interesting properties for possible future applications, e.g., as novel functional materials. N2 - Das Forschungsgebiet der supramolekularen Polymerisation hat sich in den letzten Jahrzehnten sehr rasch entwickelt, zumal da supramolekulare Polymere eine Fülle an Anwendungsmöglichkeiten in der organischen Elektronik, der Biologie oder als Funktionsmaterialen bieten (Kapitel 2.1). Während frühere Studien den Fokus auf die Untersuchung der Thermodynamik der supramolekularen Polymerisation gelegt haben (Kapitel 2.2), hat sich das akademische Interesse in jüngster Zeit dahingehend verschoben, Einblicke in kinetisch kontrollierte Selbstassemblierungsprozesse zu erhalten, um neuartige Strukturen mit faszinierenden Eigenschaften zu generieren (Kapitel 2.3). Im Zuge dieser Entwicklung wurde das Konzept der Saat-induzierten und der lebenden supramolekularen Polymerisation entwickelt, welche die Bildung von supramolekularen Polymeren mit geringer Polydispersität in kinetisch kontrollierten Prozessen ermöglichen (Kapitel 2.4). Des Weiteren wurden neue Strategien zu Erzeugung von Nanostrukturen entwickelt, die aus verschiedenen Komponenten aufgebaut sind und somit neue komplexe Strukturmotive zeigen. Eine Einteilung dieser supramolekularen Copolymere anhand einiger Literaturbeispiele und eine kurze Übersicht über die bisherigen Methoden, solche supramolekularen Strukturen zu erzeugen ist in Kapitel 2.5 dargestellt. Das Ziel der Doktorarbeit war die nicht-kovalente Synthese von erstrebenswerten supramolekularen Blockcopolymeren mittels lebender Saat-induzierter Polymerisation und zu erforschen, wie die molekulare Form der Monomerbausteine die supramolekulare Copolymerisation beeinflusst. Basierend auf der Molekülstruktur des zuvor untersuchten Perylenbisimidfarbstoffes H-PBI wurden in dieser Arbeit eine Reihe von neuen Perylenbisimiden mit identischen Amid-Seitengruppen in Imidposition und unterschiedlicher Art oder Anzahl von Buchtsubstituenten synthetisiert und charakterisiert. Die neuen Perylenbisimide wurden erfolgreich in drei Stufen durch neu entwickelte Syntheserouten erhalten, wobei von den jeweiligen Brom substituierten Perylen-3,4:9,10-tetracarbonsäuretetrabutylestern oder von N,N‘ Dicyclohexyl-1,7-dibromperylen-3,4:9,10-tetracarbonsäurebisimid ausgegangen wurde. Alle Zielverbindungen wurden im letzten Syntheseschritt mittels einer Imidisierungsreaktion der jeweiligen Perylenbisanhydridvorstufen mit N (2-Aminoethyl)-3,4,5-tris(dodecyloxy)benzamid erhalten und mittels 1H- und 13C NMR-Spektroskopie sowie mit hochauflösender Massenspektrometrie charakterisiert. Die Variation der Buchtsubstituenten hat einen starken Einfluss auf die optischen Eigenschaften der Perylenbisimidmonomere, was mittels UV/vis- und Fluoreszenzspektroskopie untersucht wurde. Die ansteigende Zahl der Methoxysubstituenten verursacht zum Beispiel eine Rotverschiebung der Absorptionsmaxima, welche mit einer Abnahme der Extinktionskoeffizienten einhergeht, und führt zu einem starken Anstieg der Fluoreszenzquantenausbeute. Außerdem wird auch die Molekülgeometrie der Perylenbisimide durch die Variation der Buchtsubstituenten beeinflusst. Mittels DFT-Rechnungen konnte gezeigt werden, dass eine Zunahme des sterischen Anspruchs der Buchtsubstituenten eine Vergrößerung des Torsionswinkels der Perylenbisimidkerne zur Folge hat. Als besonders geeignet für die im Rahmen dieser Arbeit anvisierten Studien erwies sich das mit zwei Methylgruppen in 1,7-Buchtposition substituierte MeO-PBI. Die Selbstassemblierung dieses 1,7-Dimethoxy-substituierten Perylenbisimid-Derivates wurde mit Hilfe von UV/vis-, Fluoreszenz- und FT-IR-Spektroskopie sowie mittels Rasterkraftmikroskopie detailliert analysiert (Kapitel 3). Diese Studien haben gezeigt, dass MeO-PBI in einem Lösungsmittelgemisch aus Methylcyclohexan und Toluol (2:1, v/v) in einem kinetisch kontrollierten Prozess durch schnelles Abkühlen der Monomerlösung von 90 auf 20 °C „off-pathway“ Nanopartikel ausbildet. Durch langsames Abkühlen der Monomerlösung entstehen hingegen fluoreszierende, J-aggregierte Nanofasern aufgrund von π-π-Wechselwirkungen und intermolekularen Wasserstoffbrückenbindungen. Die kinetisch metastabilen „off-pathway“ H-Aggregate können durch Zugabe einer polymeren J-Aggregat-Saat, welche durch eine Behandlung der polymeren Nanofasern mit Ultraschall gewonnen werden kann, in die thermodynamisch begünstigten J-Aggregate transformiert werden. Außerdem wurde der lebende Charakter dieser supramolekularen Saat-induzierten Polymerisation durch ein neu entworfenes multizyklisches Versuchsprotokoll nachgewiesen. Diese Experimente zur lebenden supramolekularen Polymerisation zeigen deutlich, dass der Polymerisationsprozess nur an den „aktiven“ Enden der polymeren Saat stattfinden kann und dass außerdem kaum Rekombinations- oder Kettenterminationsprozesse auftreten. Folglich ermöglicht die Methode der lebenden supramolekularen Polymerisation die Synthese von supramolekularen Polymeren mit kontrollierbarer Polymerlänge und geringer Polydispersität. In Kapitel 4 wird die Copolymerisation von MeO-PBI mit den strukturell ähnlichen 1,7 Dichlor- (Cl-PBI) und 1,7-Dimethylthiosubstituierten (MeS-PBI) Perylenbisimiden ausgeführt. Beide neuen Perylenbisimide bilden analog zu MeO-PBI „off-pathway“ Aggregate, die durch Saatzugabe in einem kinetisch kontrollierten Prozess in die thermodynamisch stabileren supramolekularen Polymere umgewandelt werden können. Die Stabilität der kinetisch gefangenen Aggregate von Cl-PBI und MeS-PBI ist jedoch verglichen mit den metastabilen Aggregaten von MeO-PBI deutlich geringer, da die π π Wechselwirkungen zwischen den molekularen Bausteinen aufgrund des vergrößerten Torsionswinkels der Peryleneinheiten stark reduziert sind. UV/vis-spektroskopische Studien zeigen, dass die Saat-induzierte Copolymerisation des kinetisch gefangenen Zustandes von MeO-PBI mit der Saat von Cl-PBI durch einen lebenden Kettenwachstumsprozess an den Polymerenden der Saat zur Ausbildung von neuartigen supramolekularen Blockcopolymeren mit A B A Blockstruktur führt. Die erzeugte A-B-A-Blockstruktur der erhaltenen Copolymere konnte eindeutig mittels Rasterkraftmikroskopie bestätigt werden, da die jeweiligen Polymerblöcke bestehend aus den einzelnen monomeren Einheiten anhand der Ganghöhe der helikalen Nanofasern unterschieden werden können. Ausführliche UV/vis- und Rasterkraftmikroskopiestudien haben außerdem demonstriert, dass, zum Beispiel durch Zugabe der Saat von MeO-PBI zu den kinetisch gefangenen Aggregaten von Cl PBI, Triblockcopolymere mit B-A-B-Blockstruktur in einer invertierten Saat-induzierten Zweikomponenten-Copolymerisation, erzeugt werden können. Dieser Wechsel der Blockstruktur kann nur durch perfekt abgestimmte Bedingungen für die Copolymerisation und bei übereinstimmender Molekülgeometrie der Monomereinheiten erreicht werden. Diese Studien zeigen erstmals, dass die Blockstruktur der supramolekularen Polymere durch das Versuchsprotokoll der lebenden supramolekularen Polymerisation variiert werden kann. Des Weiteren lieferten UV/vis-spektroskopische Untersuchungen der lebenden Copolymerisation von MeO-PBI und MeS-PBI ähnliche Ergebnisse, was darauf hindeutet, dass ebenfalls supramolekulare Blockcopolymere mit A-B-A- und B-A-B-Struktur gebildet werden können. Obwohl die einzelnen Polymerblöcke in diesem Fall wegen der identischen Helixganghöhe der Nanofasern nicht zugeordnet werden konnten, so zeigten diese Experimente doch, dass die Methode der Saat-induzierten lebenden Polymerisation nicht auf ein spezielles Paar von Monomerbausteinen limitiert ist. Im letzten Abschnitt der Doktorarbeit (Kapitel 5) wird eine systematische Studie der lebenden Zweikomponenten-Copolymerisation von Perylenbisimiden mit unterschiedlich sterisch anspruchsvollen Buchtsubstituenten dargestellt. Dementsprechend wurde eine Reihe von Perylenbisimiden mit identischen Amidseitenketten, aber unterschiedlicher Anzahl (1-MeO-PBI, MeO-PBI, 1,6,7-MeO-PBI, 1,6,7,12-MeO-PBI) oder Größe (EtO PBI, iPrO-PBI) der Alkoxybuchtsubstituenten untersucht. Die Molekülgeometrie der Monomereinheiten hat einen starken Einfluss auf das thermodynamisch und mehr noch auf das kinetisch kontrollierte Aggregationsverhalten in Lösungsmittelgemischen aus Methylcyclohexan und Toluol. Während die mono- und dialkoxysubstituierten Perylenbisimide kinetisch metastabile Zustände ausbilden, findet die Selbstassemblierung der tri- und tetramethoxysubstituierten Perylenbisimide (1,6,7-MeO-PBI, 1,6,7,12 MeO PBI) vollständig unter thermodynamischer Kontrolle statt. Die zwei 1,7 alkoxysubstituierten Perylenbisimide (EtO-PBI, iPrO-PBI) bilden analog zu MeO PBI sowohl kinetische „off-pathway“ H-Aggregate als auch thermodynamisch begünstigte J Aggregate. Verglichen mit MeO-PBI ist jedoch die Stabilität der kinetisch metastabilen Zustände von EtO-PBI und iPrO-PBI viel geringer und die Umwandlung in die thermodynamisch stabileren Aggregate geschieht daher viel schneller. Das monomethoxysubstituierte Perylenbisimid-Derivat (1 MeO PBI) bildet im Gegensatz dazu kinetisch gefangene Monomere durch intramolekulare Wasserstoffbrücken-bindungen, welche sich durch Saat-induzierte Polymerisation in die thermodynamisch begünstigteren Nanofasern transformieren lassen. Die Saat-induzierte Zweikomponenten-Copolymerisation des kinetisch gefangenen Zustands von MeO-PBI durch Saatzugabe der anderen Perylenbisimide der Reihe wurde mittels UV/vis-Spektroskopie und Rasterkraftmikroskopie analysiert. Diese Studien eröffneten, dass die Bildung von supramolekularen Blockcopolymeren nur für geometrisch passende Kombinationen der Perylenbisimide möglich ist. Dementsprechend führt die Saat-induzierte Polymerisation des kinetisch gefangenen Zustands von MeO-PBI mit den, laut DFT Rechnungen, strukturell ähnlichen Perylenbisimiden (EtO-PBI, iPrO-PBI) zur Bildung von A B A Blockcopolymeren, analog zu dem im Kapitel 4 beschriebenem Fall der Saat induzierten Copolymerisation mit Cl-PBI und MeS-PBI. Die Zugabe einer Saat der planaren Perylenbisimide (H-PBI, 1-MeO-PBI) oder der Perylenbisimide mit stark verdrehten Perylenkernen (1,6,7-MeO-PBI, 1,6,7,12 MeO PBI) zum kinetisch metastabilen Zustand von MeO-PBI führt dagegen nicht zur Bildung von Blockcopolymeren. Der Unterschied in der Molekülgeometrie dieser Monomerbausteine vermindert erheblich die Stärke der π π Wechselwirkungen zwischen den unterschiedlichen Perylenbisimiden und verhindert daher deren Copolymerisation. Die Studien zur Saat induzierten Zweikomponenten-Copolymerisation des kinetisch gefangenen Zustands von 1-MeO-PBI mit den anderen Perylenbisimiden der Serie bestätigte weiterhin, dass eine genaue Übereinstimmung der molekularen Geometrie entscheidend für die Erzeugung von supramolekularen Blockcopolymeren ist. Durch Zugabe der Saat von H-PBI zum kinetisch metastabilen Zustand von 1-MeO-PBI konnten folglich supramolekulare Blockcopolymere generiert werden. Mittels DFT-Rechnungen wurde gezeigt, dass beide Perylenbisimide einen relativ planaren Perylenkern aufweisen, was zu sehr starken, nicht-kovalenten Wechselwirkungen zwischen diesen beiden Monomerbausteinen führt. Die übereinstimmende Geometrie beider Perylenbisimide ermöglicht auch die invertierte Saat-induzierte Copolymerisation des kinetisch gefangenen Zustands von H-PBI mit 1-MeO-PBISaat, was mit einem Wechsel der Blockstruktur des supramolekularen Blockcopolymers von A B A zu B A B einhergeht. Die Zugabe der Saat der mäßig (EtO-PBI, iPrO PBI) und stark verdrehten Perylenbisimide (1,6,7-MeO-PBI, 1,6,7,12-MeO-PBI) hat im Gegensatz dazu keinen Effekt auf den kinetisch gefangenen Zustand von 1-MeO-PBI, da die Copolymerisation dieser Perylenbisimide durch die Nichtübereinstimmung der Molekülgeometrie der Monomerbausteine verhindert wird. Abschließend lässt sich zusammenfassen, dass in dieser Arbeit die supramolekulare Polymerisation und Saat-induzierte Zweikomponenten-Copolymerisation einer Reihe von Perylenbisimidmonomeren untersucht worden ist. Die Studien haben demonstriert, dass die thermodynamisch und kinetisch kontrollierten Selbstassemblierungsprozesse durch subtile Änderungen der Monomerbausteine stark variiert werden können. Außerdem zeigen die Ergebnisse, dass die lebende supramolekulare Polymerisation eine sehr leistungsfähige Methode zur Erzeugung von neuartigen supramolekularen, polymeren Nanostrukturen mit kontrollierter Blockstruktur und Längenverteilung darstellt. Die Bildung dieser supramolekularen Blockcopolymere kann nur unter präziser kinetischer Kontrolle erreicht werden und ist durch die Komplementarität der einzelnen molekularen Komponenten stark beeinflusst. Diese aufschlussreichen Studien bilden möglicherweise die Grundlage für ein rationaleres Design neuer Monomerbausteine zur nicht-kovalenten Synthese von hochkomplexen, supramolekularen Strukturen mit potentiell einzigartigen Eigenschaften für mögliche Anwendungen, beispielsweise als neuartige Funktionsmaterialien. KW - Supramolekulare Chemie KW - Perylenbisdicarboximide KW - Lebende Polymerisation KW - Aggregation KW - Supramolecular Block Copolymers KW - Perylenbisimides KW - Kinetic Self-assembly KW - Living Polymerisation KW - Organische Chemie Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-193004 ER -