Polarization Effects for Hydrogen-Bonded Complexes of Substituted Phenols with Water and Chloride Ion.

ABSTRACT: Variations in hydrogen-bond strengths are investigated for complexes of nine para-substituted phenols (XPhOH) with a water molecule and chloride ion. Results from ab initio HF/6-311+G(d, p) and MP2/6-311+G(d, p)//HF/6-311+G(d, p) calculations are compared with those from the OPLS-AA and OPLS/CM1A force fields. In the OPLS-AA model, the partial charges on the hydroxyl group of phenol are not affected by the choice of para substituent, while the use of CM1A charges in the OPLS/CM1A approach does provide charge redistribution. The ab initio calculations reveal a 2.0-kcal/mol range in hydrogen-bond strengths for the XPhOH⋯OH(2) complexes in the order X = NO(2) > CN > CF(3) > Cl > F > H >OH >CH(3) > NH(2). The pattern is not well-reproduced with OPLS-AA, which also compresses the variation to 0

SUBMITTER: Jorgensen WL 

PROVIDER: S-EPMC2996042 | biostudies-literature | 2007 Nov

REPOSITORIES: biostudies-literature