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Molecular structures and intramolecular interactions in dimethyl cyclohexane isomers
Author(s) -
Klimkowski V. J.,
Manning J. P.,
Schäfer Lothar
Publication year - 1985
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.540060609
Subject(s) - intramolecular force , cyclohexane , ab initio , chemistry , molecular geometry , ab initio quantum chemistry methods , computational chemistry , basis set , gaussian orbital , group (periodic table) , methyl group , crystallography , molecule , stereochemistry , density functional theory , organic chemistry
The geometries of ten isomers of dimethyl cyclohexane were determined by ab initio gradient geometry refinement with the 4‐21G basis set. It is found that many intramolecular interactions are clearly manifested by correlated structural trends, and that they are consistent with strain energies calculated by employing previously defined ab initio group equivalents. Specifically, non‐bonded interactions are found between two adjacent methyl groups in some of the forms, and between axial methyl groups and adjacent axial CH bonds in others. Unperturbed axial CH and CC bonds are consistently longer than equatorial bonds. In general, CH bonds which are involved in non‐bonded repulsive interactions are shortened, i.e., strengthened, and the corresponding HCC angles are large, compared to non‐interacting parameters.