Jahn-Teller effect in trigonal mu-oxoclusters

摘要

A theory of the Jahn-Teller effect in trinuclear Cr~(III) and Fe~(III) mu-oxocomplexes based on the generalized angular overlap model is developed.The central bridging O atom is not localized at the center of the triangle formed by the metal atoms.Rather,it executes a free or hindered motion along a circular groove of radius 0.05-0.1 A.The theory provides a qualitative explanation for apparent discrepancy between the X-ray structural data and the results of the heat capacity,magnetic susceptibility,and inelastic neutron scattering measurements.Namely,X-ray structural data correspond to a regular triangle symmetry while other data correspond to an equilateral or even irregular triangle symmetry.