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Computational methods for conformational analysis of unsymmetrical 1,3-diamines: 3-aminotropanes

✍ Scribed by Lewin, Anita H.; Sorensen, Jennifer B.; Dustman, John A.; Bowen, J. Phillip

Publisher
John Wiley and Sons
Year
1999
Tongue
English
Weight
282 KB
Volume
20
Category
Article
ISSN
0192-8651

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✦ Synopsis

A comparative study has been performed to evaluate the ability of a range of computational theories to predict the relative basicity and the Ž . conformations of diamine systems. Specifically, molecular mechanics MM3 , Ž . Ž . 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 Ž . water solvent by setting the dielectric constant to 80 . Ab initio and semiempirical calculations, in contrast, give inconsistent and incorrect results.

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