STRENGTHS OF BONDING AND DEGREE OF DISTORTION FROM OCTAHEDRAL SYMMETRY BY MOSSBAUER SPECTROSCOPY

The use and the limitations of Mössbauer quadrupole splittings in the differential analysis of iron(II) and iron(III) in strong field complexes is investigated. By way of example, some literature Mössbauer data on dithiolene complexes of iron are interpreted in terms of the environment of the iron atom. In the six-coordinated complexes, there is considerable distortion from octahedral symmetry (corresponding to 3 δ∼1200 cm-1). In the five-coordinated complexes, the distortion is also large (corresponding to 3 δ∼2200 cm-1), and the values of the ratio, β/ga, of the molecular orbital coefficients are found to follow the trend that would be expected from the usual bond strengths of the various ligands. © 1969 Springer-Verlag.