Collect. Czech. Chem. Commun. 1984, 49, 2837-2856

MO study of Td-D4h equilibrium in complexes of transition metals. II. Equilibrium in tetrafluoro and tetrabromo complexes of atoms of the first transition row

Peter Pelikána and Marek Liškab

a Department of Physical Chemistry, Faculty of Chemical Technology, Slovak Institute of Technology, 812 37 Bratislava
b Common Laboratory of CChV Slovak Academy of Sciences and VVUS, 912 50 Trencin


The CNDO method for transition metals in the UHF version has been used to study the equilibrium of configuration isomers of tetrahedral and square-planar tetrafluoro and tetrabromo complexes of the first transition row atoms in the oxidation degree II (Mn(II), Fe(II), Co(II), Ni(II), Cu(II) both in low-spin and in high-spin states. The results show that the ability (given by electronic structure of the central atom) to form the square-planar complexes decreases monotonously in the series: Mn(II) > Fe(II) > Co(II) > Ni(II) > Cu(II). With respect to the effect of the electronic structure of ligands, the same ability decreases in the series: F- > Cl- > Br-.