| Abstract: | For complexes of transition metals (manganese, iron, cobalt, nickel) with monodentate ligands, equilibrium metal-ligand distances
and ligand bond energies in the first and second coordination spheres have been calculated by the CNDO method. Some effects
of ligand bond energies in different coordination spheres are analyzed. These effects significantly differ between the first
and second coordination spheres. In the first sphere, the ligand bond energy is mainly determined by the nature of the central
ion and the type of donor atom of the ligand, but weakly depends on the structure of the ligand. Conversely, in the second
coordination sphere, the ligand bond energy weakly depends on the nature of the central ion and the type of donor atom, but
considerably depends on the structure of the ligands in the first coordination sphere. In the second coordination sphere,
ligand binding is determined by ligand interactions with both the central ion and the ligands of the first sphere. In the
general case, when strong specific interactions between ligands are absent, the energetics of the second sphere is determined
by the size of the inner-spheric ligands, which may be considered to be a specific steric effect.
V. I. Vernadskii Institute of Geochemistry and Analytical Chemistry. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 2, pp. 370–374, March–April, 1995.
Translated from L. Smolina |
