THEORETICAL STUDIES OF INCLUSION COMPLEXES OF ALPHA- AND BETA-CYCLODEXTRIN WITH BENZOIC ACID AND PHENOL

摘要

A series of semiempirical molecular orbital calculations using the AM1 method were performed on the inclusion complexes of alpha- and beta-cyclodextrin with benzoic acid and phenol in the ''head-first'' and ''tail-first'' positions. The AM1 results show that alpha-cyclodextrin complexes with both guest compounds in the ''head first'' position are more stable than in the ''tail-first'' position, while the beta-cyclodextrin complex with phenol in the ''tail-first'' position is more stable, but with benzoic acid, the ''head-first'' position is more stable. The driving forces for complex formation were investigated based on different intramolecular and intermolecular interactions. In addition, 1SCF AM1 calculations were performed on the beta-cyclodextrin complexes with benzoic acid in the ''tail-first'' and ''head-first'' positions with the benzoic acid moved stepwise along the Z-axis of the beta-cyclodextrin principal axis coordinate system. (C) 1997 John Wiley & Sons, Inc. [References: 64]