Mössbauer spectra of compounds containing iron(II) in strong-field tetragonal environments

Abstract

Mössbauer spectra of compounds having the general formulae bis(1, 2-cyclohexanedione dioxime) iron (II) XY and phthalocyanineiron(II)(Z)2, where X, Y, Z represent ligands at the axial positions, have been measured at 77°K and in some cases at room temperature. The spectra consist of quadrupole-split doublets, from which two parameters have been obtained : the isomer shift δ and the quadrupole splitting, ΔEQ. These parameters appear to be linearly related to each other within both series of complexes. It is argued that such a relationship exists only when the ligands can be considered to be either pure π-acceptors or pure π-donors.