Collect. Czech. Chem. Commun. 1982, 47, 1556-1569

MO study of Td-D4h equilibrium in complexes of transition metals. Equilibrium in tetrachloro complexes of atoms of the first transition row

Petr Pelikána and Marek Liškab

a Department of Physical Chemistry
b Department of Inorganic Chemistry, Slovak Institute of Technology, 880 37 Bratislava


The CNDO method in UHF version has been used for study of equilibrium of configuration isomers of tetrahedral and square-planar tetrachloro complexes of the first transition row atoms in the oxidation degree II (Mn(II), Fe(II), Co(II), Ni(II), Cu(II)). From the results it follows that the ability (conditioned by electronic structure of the central atom) to form the square-planar complexes decreases in the series Mn(II) > Fe(II) > Co(II) > Ni(II) > Cu(II). Several authors state the fact that the most important task of quantum chemistry is to develop procedures for calculation of rate and equilibrium constants of chemical reactions1,2. At the same time it is emphasized that these procedures should be independent of experimental data. By this term the authors mean such experimental data which are in some way connected with the reaction studied, and not the general experimental experience which (after transformation into axioms) can represent a basis of the used method.