Russian Chemical Bulletin, Vol. 46, No. 7, July, 1997, 1278-1284.

Study of amino- and pyridyl-containing zinc(II) and cadmium(II) complexes by molecular mechanics using a force field based on the Gillespie-Kepert model

Vladimir L. Melnikov and Igor V. Pletnev

Moscow State University, Moscow, 119899 Russia

Abstract - A new approach combining the molecular mechanics (MM) method and the Gillespie- Kepert model was applied to calculate the geometry and strain energy of zinc(II) and cadmium(II) complexes with amino- and pyridyl-containing ligands. High accuracy of calculations of the geometry was demonstrated for more than 20 complexes of these metals. Typical r.m.s. deviations between the calculated and experimental values (X-ray diffraction analysis) were 0.02 A for bond lengths, 2 deg. for bond angles, and 4 deg. for torsion angles. The size-match selectivity of several macrocycles and polydentate open-chain ligands was studied. Correlations between the calculated strain energies of metal complexes and the experimental values of their stability constants and enthalpies of formation are discussed.