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Molecular mechanics (MM) and MM‐EHMO conformational analysis of the diastereoisomers of 3‐amino‐1,2,3‐triphenyl‐1‐propyl chloride
Author(s) -
Ivanov Petko M.,
Momchilova Tatyana G.,
Pojarlieff Ivan G.
Publication year - 1991
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.540120404
Subject(s) - diastereomer , chemistry , van der waals force , dipole , computational chemistry , force field (fiction) , crystallography , chloride , alkyl , charge (physics) , stereochemistry , molecule , organic chemistry , physics , quantum mechanics
The conformations of simple alkyl substituted 1,2‐diphenylethanes and the diastereoisomers of 3‐amino‐1,2,3‐triphenyl‐1‐propyl chloride were studied by the MM2 force field with the addition of electrostatic corrections to the aromatic force field as proposed recently by Allinger and Lii (dipole‐dipole interactions) and independently by Pettersson and Liljefors (charge‐charge interactions). Computations were also carried out with a modified version of the MM2 program utilizing the MM3 van der Waals potential function and parameters for C (type 2, sp 2 hybridized) and H (type 5). The inclusion of dipole moments for the C sp 2 C sp 3 and C sp 2 H bonds significantly improves the results. A lower value for the V 1 parameter for the torsional unit C ar C al C al C ar had to be used instead of the MM2 value of 2.1 kcal/mol. Computations were carried out also with the hybrid MM‐EHMO procedure. The latter method appears to work correctly also with 1,2,3‐triphenylpropane systems.