Campus Units

Ames Laboratory

Document Type

Article

Publication Version

Published Version

Publication Date

9-2009

Journal or Book Title

Journal of Physical Chemistry B

Volume

113

Issue

43

First Page

14413

Last Page

14420

DOI

10.1021/jp904826v

Abstract

The solvation of alanine is investigated, with a focus on adding a sufficient number of discrete water molecules to determine the first solvation shell for both the nonionized (N) and zwitterionic (Z) forms to converge the enthalpy of solvation and the enthalpy difference for the two forms of alanine. Monte Carlo sampling was employed using the generalized effective fragment potential (EFP) method to determine the global minimum of both conformers, with the number of EFP water molecules ranging from 32−49. A subset of sampled geometries were optimized with second-order perturbation theory (MP2) using the 6-31++G(d,p) basis set. Single point energies were calculated at these geometries using the polarizable continuum model (PCM). The predicted 298.15 K enthalpy of solvation ranges for MP2/6-31++G(d,p) and MP2+PCM//MP2/6-31++G(d,p) are 10.0−13.2 kcal/mol and 10.1−12.6 kcal/mol, respectively.

Comments

Reprinted (adapted) with permission from Journal of Physical Chemistry B 113 (2009): 14413, doi:10.1021/jp904826v. Copyright 2009 American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

Included in

Chemistry Commons

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