Premium
Mono‐ and poly‐ligated complexes of Zn 2+ : An ab initio analysis of the metal–ligand interaction energy
Author(s) -
Gresh Nohad,
Stevens Walter J.,
Krauss Morris
Publication year - 1995
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/jcc.540160704
Subject(s) - chemistry , interaction energy , formate , computational chemistry , ab initio , formamide , valence (chemistry) , binding energy , metal , solvation , ligand (biochemistry) , intermolecular force , ion , molecule , atomic physics , organic chemistry , physics , catalysis , biochemistry , receptor
Detailed investigation of the binding energetics of Zn 2+ to biologically relevant model ligands has been performed by large basis set restricted Hartree‐Fock computations. This list includes neutral and anionic ligands that model the sidechains of the amino acid residues of proteins as well as those involved in binding to the metal during enzymatic activation: water, formaldehyde, formamide, imadazole, methylthiol, and the formate, hydroxyl, methoxy, methylthiolate anions. The decomposition of the intermolecular interaction energy into its components (Coulomb, exchange, polarization, and charge transfer) has been done within the frozen fragment reduced variational space procedure (RVS) developed by Stevens and Fink [W. J. Stevens and W. H. Fink, Chem. Phys. Lett., 139 , 15 (1987)]. The use of the RVS procedure was dictated by the very large magnitudes of the second‐order interaction energy terms in the divalent cation complexes and the need to obtain polarization and charge‐transfer contributions in a variational sense. The behavior of the interaction energy with radial and angular variation of the approach of the metal to the ligand is explored. In addition, the nonadditive behavior of polyligated complexes is studied for water and formate. This will also provide the data for a subsequent fit to a molecular mechanics procedure that considers the second‐order interactions. © 1995 by John Wiley & Sons, Inc.