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Computational methods for conformational analysis of unsymmetrical 1,3‐diamines: 3‐aminotropanes
Author(s) -
Lewin Anita H.,
Sorensen Jennifer B.,
Dustman John A.,
Bowen J. Phillip
Publication year - 1999
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/(sici)1096-987x(199910)20:13<1371::aid-jcc4>3.0.co;2-r
Subject(s) - ab initio , computational chemistry , chemistry , protonation , force field (fiction) , ab initio quantum chemistry methods , molecular mechanics , solvent effects , basis set , thermodynamics , solvent , molecule , molecular dynamics , density functional theory , quantum mechanics , organic chemistry , physics , ion
A comparative study has been performed to evaluate the ability of a range of computational theories to predict the relative basicity and the conformations of diamine systems. Specifically, molecular mechanics (MM3), semiempirical (AM1), and ab initio (Hartree–Fock) methods have been used in the conformational analyses of unprotonated, monoprotonated, and diprotonated 3‐aminotropanes, a pair of isomeric 1,3‐diamines. Use of the molecular mechanics force field, with the recently determined parameter set for protonated amines, affords results that are in agreement with experimental data, when corrected for water solvent (by setting the dielectric constant to 80). Ab initio and semiempirical calculations, in contrast, give inconsistent and incorrect results. ©1999 John Wiley & Sons, Inc. J Comput Chem 20: 1371–1378, 1999