Russian Journal of Coordination Chemistry, Vol. 23, No. 3, 1997, pp. 189-196.
Translated from Koordinatsionnaya Khimiya, Vol. 23, No. 3, 1997, pp. 205-213.

The Molecular Mechanic Approach to Coordination Compounds: Force Field Based on the Gillespie-Kepert Model

I. V. Pletnev and V. L. Melnikov

Moscow State University, Moscow, 119899 Russia

Abstract - The set of parameters for calculating the geometry of coordination compounds is suggested on the basis of the molecular mechanic approach complemented by the Gillespie-Kepert model. The high accuracy of the calculations is demonstrated by the examples of 23 nickel(ll) (high-spin state) and iron(ll) (high- and low-spin states) complexes with pyridyl- and amine-containing reagents, including the compounds having severely distorted coordination geometry. The typical root-mean-square deviations from the experiment (X-ray diffraction) do not exceed 0.02 A for the bond lengths, 2 for the bond angles, and 5 for the torsional angles. The calculations within the suggested approach are used for studying the selectivity of the macrocyclic reagents to the size of the metal ion and for describing the trigonal twisting in the coordination complexes.