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 - 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 - Engels, Bernd A1 - Peyerimhoff, S.D. T1 - Theoretical study of FC\(_2\)H\(_4\) N2 - Large-scale multireference configuration interaction (MRD-CI) calculations in a quite flexible AO basis are employed to study the energy hypersurface for the reaction intermediate FC\(_2\)H\(_4\) • The reaction F + C\(_2\)H\(_4\) -> FC\(_2\)H\(_4\) as weil as the 1,2 migration of the fluorine atom in FC\(_2\)H\(_4\) is investigated. In addition the rotation around the CC bond in the optimum conformation is studied. The absolute minimum in the potential energy is found for the asymmetric structure but the symmetric structure is also found to be stable with respect to the dissociation, so that a shuttling of the fluorine atom is in principle possible but highly unlikely because ( l) the activation energy is high ( II 5-130 kJ fmol) and the saddle point lies only 4(}-50 kJ jmol below the dissociation Iimit of F + C\(_2\)H\(_4\) and (2) the competitive motion, i.e., rotation around the CC axis, is nearly free (I 1-17 kJ/mol). KW - Organische Chemie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58824 ER - TY - JOUR A1 - Engels, Bernd A1 - Peyerimhoff, S.D. T1 - The hyperfine coupling constants of the X\(^3\)Σ\(^-\) state of NH : Influence of polarization functions and configuration space on the description of spin polarization N2 - The hyperfine coupling constants for the \(^3\)Σ\(-\) ground state of the NH molecule are determined by configuration interaction calculations whereby the infl.uence of polarization functions as weil as of the configuration space on the spin polarization mechanism is analysed. The dipolar part Au(N) and Au(H) can be obtained very reliably without much computational effort (A .. (N) == -45·3 MHz and A"(H) = -62·3 MHz). The value for the isotropic contribution a1.., in the best AO basis and MRD-CI treatment is - 64·5 MHz for H and 16·6 MHz for nitrogen compared to the corresponding experimental quantities of -66 MHz and 19 MHz respectively. Their determination depends on a subtle balance of the lu, 2u and 3u shell correlation description, whereby the dominant contribution to a1..,(H) results from the 2u shell. It is shown that the often good agreement of a110 values with experiment in a small basis singledouble configuration interaction treatment results from a cancellation of two errors. KW - Organische Chemie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58832 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. A1 - Skell, P.S. T1 - Theoretical study of the potential energy surface governing the stereochemistry in ClC\(_2\)H\(_4\) reactions N2 - Large-scale multireference configuration interaction calculations in a double·t·type AO basis including polarization functions are carried out for the potential surface of the ClC\(_2\)H\(_4\9 system. The charge distribution for various extreme points of the surface is discussed. The absolute minimum is found for an asymmetric ClC2H4 structure. The symmetrical bridged nuclear conformation is also found to be stable with respect to dissociation into Cl + C\(_2\)H\(_4\)• The activation energy for rotation about the C-C axis is calculated tobe around 18 kJ/mol, which is comparable tothat for the 1,2 migration {around 26 kJ/mol). The stereochemistry is governed by the fact that addition of CI to C\(_2\)H\(_4\) (or dissociation) is a two-step reaction proceeding through a symmetrica1 intermediate. The direct addition pathway possesses a small barrier of about 8 kJ jmol. KW - Organische Chemie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58851 ER - TY - JOUR A1 - Leininger, H. A1 - Lanzendörfer, F. A1 - Christl, Manfred T1 - Über die Reduktion des Benzvalenozonids zum cis-1,3-Cyclobutandimethanol mit LiAlH\(_4\) N2 - No abstract available KW - Organische Chemie Y1 - 1983 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58130 ER - TY - JOUR A1 - Leininger, H. A1 - Christl, Manfred A1 - Wendisch, D. T1 - Über die Oxidation von Benzvalen mit Singulett-Sauerstoff zum Bicyclo[1.1.0]butan-endo,endo-2,4-dicarbaldehyd N2 - No abstract available KW - Organische Chemie Y1 - 1983 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58142 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 - 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 - Leininger, H. A1 - Kemmer, P. T1 - Über das cis-Glycol und das Epoxid des Benzvalens N2 - No abstract available KW - Organische Chemie Y1 - 1984 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58174 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 - JOUR A1 - Christl, Manfred A1 - Mattauch, B. T1 - Versuche zur Synthese eines formalen Nitriloxid-Addukts des Benzols. 1,3-Dipolare Cycloadditionen an Bicyclo[2.2.0]hex-5-en-2,3-dicarbonsäureanhydrid, Dewarbenzol und 1,4-Cyclohexadien N2 - No abstract available KW - Organische Chemie Y1 - 1985 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58216 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 - 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 - Lang, R. A1 - Herzog, C. T1 - The Synthesis of Octavalene (Tricyclo[5.1.0.0\(^{2,8}\)]octa-3,5-diene) and Several Substituted Octavalenes N2 - No abstract available KW - Organische Chemie Y1 - 1986 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58254 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 - 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 - 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 - Bentley, T. W. A1 - Christl, Manfred A1 - Kemmer, R. A1 - Llewellyn, G. A1 - Oakley, J. E. T1 - Kinetic and Spectroscopic Characterisation of Highly Reactive Methanesulfonates. Leaving Group Effects for Solvolyses and Comments on Geminal Electronic Effects Influencing S\(_N\)1 Reactivity N2 - Highly reactive methanesulfonates (mesylates, ROMs) have been prepared from 1-phenylethanol. cyclohex-2-en-1-ol, diphenylmethanol and p-methoxybenzyl alcohol by treatment with methanesulfonyl chloride and triethylamine in dichloro- or trichloro-methane at - 20 to 0 °C. The mesylates. characterised in solution by \(^1\)H and \(^{13}\)C NMR at -20 °C, were obtained in satisfactory purity (ca. 95%) in cold solutions but they decomposed by reaction with chloride, triethylamine or the parent alcohol. Rate constants for solvolyses in aqueous acetone and aqueous ethanol have been determined by a fast response conductimetric method. Product selectivities for solvolyses of pmethoxybenzyl mesylate in aqueous ethanol and methanol at 0 °C have been determined by HPLC. From additional new or Iiterature kinetic data for solvolyses of corresponding bromides. chlorides and p-nitrobenzoates (OPNB). Br/CI. OMs/Br and OMs/OPNB rate ratios were calculated; the results are consistent with electronic effects stabilising the carbocationic transition states and increasing OMs/Br rate ratios for these SN 1 solvolyses; none of the evidence supports a geminal electronic effect on Br/CI rate ratios (e.g. caused by stabilisation of the initial state in pmethoxybenzyl chloride). Steric effects on ester /halide rate ratios for solvolyses of tertiary substrates are confirmed. Relative rates over a 10\(^{16}\) range for ester and halide leaving groups are evaluated for solvolyses of 1-phenylethyl substrates in 80% ethanol-water. updating previous work by Noyce et al. (1972). KW - Organische Chemie Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58748 ER - TY - JOUR A1 - Engels, Bernd A1 - Peyerimhoff, S. D. T1 - Theoretical study of the bridging in β-Halo Ethyl N2 - Large-acale multi-reference configuration interaction (MRD-CI) calculations in a quite flexible AO basis are employed to study the energy hypersurface for the reaction intermediates XC\(_3\)H\(_4\) with X = Cl, Br and F. Particular emphasis is therby placed on determining the equilibrium conformations, the CH\(_2\) rotation barrier and the energy surface for a possible bridging (shuttling motion (1a] of X between the two carbon centers). The absolute minimum in the potential energy surface is found in all three cases for the asymmetric ß-halo radical in general agreement with ESR data at an XCC angle of ca. 110°, a c-c separation somewhat shorter than a single bond and an approximate sp3 type hybridization (\(\alpha _2 \approx \) 135-140°). In FC\(_2\)H\(_4\) the energy difference between the minimum in the symmetric conformation and the absolute minimum is found to be more than 30 kcal so that shuttling seems impossible in agreement with experimental findings. In BrC\(_2\)H\(_4\) the difference between these two potential minima is only between 1-2 kcal, i.e., smaller than the barrier to CH\(_2\), rotation, so that· shuttling is favored, while ClC\(_2\)H\(_4\) takes an intermediate position between these extremes. The use of correlated wavefunctions is found to be quite important for such a study; the results are related to various kinetic studies of these radicals. KW - Organische Chemie Y1 - 1986 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58779 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 - 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 - Peyerimhoff, S.D. A1 - Karna, S.P. A1 - Grein, F. T1 - The hyperfine coupling constants of the five lowest states of CH : An ab initio MRD-CI study N2 - No abstract available KW - Organische Chemie Y1 - 1988 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58807 ER - TY - JOUR A1 - Karna, S. A1 - Grein, F. A1 - Engels, Bernd A1 - Peyerimhoff, S.D. T1 - The hyperfine coupling constants of \(^{19}\)F\(_2\) N2 - The isotropic (a\(_{iso}\)) and dipolar (A\(_{dip}\)) hyperfine coupling constants of 19F2 were obtained from MRD-CI wave functions using a variety of basis sets. In series I, increasing numbers of d functions were added to a 5s4p contracted Huzinaga!Dunning basis. In series II, the 5s3p basis set was uncontracted in several steps until 9s5p was reached, to which were added from one to three d-polarization functions. Cl parameters (selectioo threshoids and the number of reference coofiguratioos) were also varied. A study of the R dependence of aiso and Adip was perfonned. The best values obtained at R\(_e\) are 260 G for a\(_{iso}\) and 308 G for A\(_{dip}\)• compared with experimental values of about 280 G for a;10 and 320 G for A\(_{dip}\)· KW - Organische Chemie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58817 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 - 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 - 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 - Freitag, G. A1 - Brüntrup, G. T1 - Tricyclo[4.1.0.0\(^{2,7}\)]hept-3-ene durch Umlagerung von 7-endo-Brom- und 7-endo-Chlortetracyclo[4.1.0.0\(^{2,4}\).0\(^{3,5}\)]heptanen N2 - No abstract available KW - Organische Chemie Y1 - 1978 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58029 ER - TY - JOUR A1 - Christl, Manfred A1 - Herbert, R. T1 - Unusual Carbon Shielding Effects of Cyclopropanes and Double Bonds in Strained Bicyclo[3.1.0]hexanes and Cyclopentenes N2 - Carbon-13 shieldings and one-bond \(^{13}\)C-H coupling constants of bicydo[2.1.1]hexane, bicydo[2.l.l]hex- 2-ene, tricydo[3.1.1.0\(^{2.4}\)]heptane and benzvalene are presented and compared. to the data of related. compounds. H a bicydo[3.1.0]hexane system is part of a rigid skeleton, the cydopropane ring exerts spedfk: 'Y substituent eflects of two ldnds. In the case of the bicyclobexane boat form an upfield shift of the C-3 signal is observed and in tbe esse of the chair form a downfield shift of 15-20 ppm. Compared to the corresponding cydopentanes the double bond in strained cydopentenes causes downfield shifts of the C-4 absorption. 1bis eftect increases witb increasing strain, reaching 8 45.9 ppm maximum in benzvalene. Hence it is tbe only known bicydo[l.l.O]butane baving 8 reversed order of carbon shieldings. The downfield shifts are e:xplained by means of simple orbital interaction schemes. KW - Organische Chemie Y1 - 1979 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58038 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 - 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 - 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 - 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 - 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 - 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 - 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 - Bast, K. A1 - Christl, Manfred A1 - Huisgen, R. A1 - Sustmann, R. T1 - Zur Anlagerung des Benzonitriloxids an α,β-ungesättigte Carbonsäureester N2 - No abstract available KW - Organische Chemie Y1 - 1973 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-57912 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 - 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 - 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 - Christl, Manfred A1 - Heinemann, U. A1 - Kristof, W. T1 - Thermal Rearrangement of Some Endo-Endo'-Bridged Bicyclo[1.1.0]butanes N2 - No abstract available KW - Organische Chemie Y1 - 1975 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-57967 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 - 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 - 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 - Schreck, Michael A1 - Christl, Manfred T1 - Generation and Interception of 1-Oxa-3,4-cyclohexadiene N2 - No abstract available KW - Chemie Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31601 ER - TY - JOUR A1 - Christl, Manfred A1 - Braun, Martin T1 - Generation and interception of 1-OXA-2,3-Cyclohexadiene and 1,2,4-Cyclohexatriene N2 - The cycloadducts 6 and 7 of tricyc1o[4.1.0.0 2 ,7)hepta- 3,4-diene (~) with styrene and 1,3-butadiene rearrange to unusual products on thermolysis, namely the cycloheptatriene derivatives ~ and 10. 1-0xa-3,4-cyclohexadiene (20) is generated smoothly from 6,6-dichloro-3-oxabicyclo[3.1.0]hexane (22) and n-butyllithium. 1-0xa-2,3-cyclohexadiene (11) is formed from 6-exo-bromo-6-endo-fluoro-2-oxabicyclo[ 3.1.0]hexane (30) and methyllithium. In the presence of activated olefins, this reaction provides an efficient route to 28 and 33 - 38, the trapping products of 21. Interestingly, [2+2]-cycloadditions do not take place at the same double bond of 21 as [4+2]-cycloadditions. The reactions of 1,3-cyclopentadiene and indene with bromofluorocarbene afford 6-exo-bromo-6-endo-fluorobicyclo[3.1.0]hex-2-ene (50) and its benzo derivative ~, respectively. On treatment of these compounds with methyl lithium in the presence of styrene, the interception products 53 and 47 of 1,2,4-cyc10- hexatriene (44) and its benzo derivative 43, respectively, are formed in good yields. KW - Chemie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-56566 ER - TY - JOUR A1 - Gleiter, Rolf A1 - Bischof, Peter A1 - Christl, Manfred T1 - Electronic Structure of Octavalene : Photoelectron Spectroscopic Investigations N2 - The He I photoelectron (PE) spectra of octavalene (5) as weil as its hydrogenated products 6-8 have been investigated. The assignment given is based on an empirical comparison of 5-8 with related compounds, a ZDO model, and semiempirical and ab initio calculations. Within the ZDO model the interaction between the buta.diene moiety and the bicyclobutane fragment of 5 is described by a resonance integral of -2.3 eV. The orbitalsequence of 5 is found tobe 2a\(_2\) (\(\pi\)-\(\sigma\)), 9a\(_1\) (\(\sigma\)), 3b1 (\(\pi\) - \(\sigma\)), 1a\(_2\) (\(\sigma\) + \(\pi\)), 2b\(_1\) (\(\sigma\) + \(\pi\)). KW - Chemie KW - Octavalen KW - Photoelektron Y1 - 1986 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31588 ER - TY - JOUR A1 - Christl, Manfred A1 - Schreck, Michael T1 - 1,2,3,5,8,8a-Hexahydronaphthalin aus 1,2-Cyclohexadien N2 - Reaktionen von 1,3-Butadien und einigen seiner Methylderivate mit 1a und 1- Methyl-1,2-cyclohexadien 1b sowie den Übergang der [2 + 2]-Cycloaddukte 2 und 3 in das bisher unbekannte 1,2,3,5,8,8a-HexahydronaphthaJin 4a und einige seiner Methylderivate KW - Chemie KW - Butadien Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31656 ER -