TY - JOUR
A1 - Reuter, W.
A1 - Engels, Bernd
A1 - Peyerimhoff, S.D.
T1 - The Reaction of Singlet and Triplet Methylen with Ethene - A Multi-Reference CI Study
N2 - Large-scale multireference configuration interaction (MRD-CI) calculations in a flexible atomic orbital (AO) basis are employed to study the reaction of C\(_2\)H\(_4\) with CH\(_2\) in its firSt triplet and singlet state. The minimum energy path (MEP) of both reactions is calculated, and different mechanisms are discussed. To examine the possible participation of the singlet state in the overall reaction starting from the triplet channel and terminating in the singlet-state c-C\(_3\)H\(_6\), various cuts through both hypersurfaces are calculated. lt is found that favorable interconversion from the trip1et to the singlet surface can only occur at !arge separations of the two fragments of CH2 and C\(_2\)H\(_4\). Experimental data considering the vibrational motion of CH\(_2\) in connection with the relative position of both surfaces are used to obtain an estimate for the overall barrier of the reaction. The height of the barrier is about 6 kcal/mol, while the barrier of the pure triplet reaction is calculated to be 7-9 kcal/mol.
KW - Organische Chemie
Y1 - 1992
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58923
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 - 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 - 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 - Kaupp, Martin
A1 - Schleyer, Paul von Rague
T1 - Do Low-Coordinated Group 1-3 cations M\(^n\) \(^+\)L\(_m\) (Mn\(^+\) = K\(^+\), Rb\(^+\), Cs\(^+\), Ca\(^{2+}\), Sr\(^{2+}\), Ba\(^{2+}\), Sc\(^{3+}\), Y\(^{3+}\), La\(^{3+}\); L = NH\(_3\), H\(_2\)0, HF; m = 1-3) with a Formal Noble-Gas Electron Configuration Favor Regular or "Abnormal" Shapes?
N2 - No abstract available
KW - Anorganische Chemie
Y1 - 1992
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60111
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 - Stangl, R.
A1 - Jelinek-Fink, H.
T1 - Zur Kenntnis der thermischen Umlagerung des Bicyclo[1.1.0]butan-Systems. Eine kinetische Studie des Übergangs von Tricyclo[4.1.0.0\(^{2,7}\)]heptanen in Bicyclo[3.2.0]hept-6-ene
T1 - On the Thermal Rearrangement of the Bicyclo[1.1.0]butane System. A Kinetic Investigation of the Conversion of Tricyclo[4.1.0.0\(^{2,7}\)]heptanes into Bicyclo[3.2.0)hept-6-enes
N2 - No abstract available
KW - Organische Chemie
KW - 3-Methenonaphthalenes
KW - 4-tetrahydro-
KW - kinetics of thermolysis
KW - Benzocycloheptene derivatives
KW - Bicyclo[1.1.0]butanes
KW - rearrangement
KW - Tricyclo[4.1.0.02.7]heptanes
KW - kinetics of thermolysis
KW - Bicyclo[3.2.0]hept-6-ene derivatives
Y1 - 1992
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58623
ER -
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 - Hegmann, J.
A1 - Ditterich, E.
A1 - Hüttner, G.
A1 - Christl, Manfred
A1 - Peters, K.
A1 - Peters, E.-M.
A1 - Schnering, H. G. von
T1 - δ-Chlor-δ-lactone aus γ-Oxoketenen
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 - δ-Lactones
KW - δ-chloro-
KW - β-Lactones
Y1 - 1992
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58649
ER -
TY - JOUR
A1 - Christl, Manfred
A1 - Braun, Martin
A1 - Müller, Germar
T1 - 1,2,4-Cyclohexatrien, ein Isobenzol, und Bicyclo[4.4.0]deca-1,3,5,7,8-pentaen, ein Isonaphthalin : Erzeugung und Abfangreaktionen
N2 - No abstract available
Y1 - 1992
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-30249
ER -