Square planar to rectangular distortion in transition-metal compounds of edge-sharing square planar units MX(4)

In transition metal compounds of edge-sharing square planar MX(4) units (M=group 10, group 11; X=O, S, Se), a square planar to rectangular distortion is observed, The causes for this distortion in MX(2) ladder chains, M(3)X(4) honeycomb layers, and 3D MX lattices were examined by performing extended Huckel tight binding electronic band structure calculations. The primary cause for the distortion is the reduction of the four-electron two-orbital destabilizing interactions among the p-orbitals of X. (C) 1997 Academic Press.