Pyridine base adducts of manganese(II) and iron(II) complexes of TTA and STTA

Abstract

Octahedral high-spin adducts of the type ML 2B 2, where M = Mn(II) and Fe(II), L = thenoyltrifluoroacetone and monothiothenoyltrifluoroacetone and B = pyridine and γ-picoline, were isolated in the atmosphere and the properties of these adducts were investigated to clarify the effect of the sulfur-coordination. The assignments of the metal-ligand stretching bands in IR spectra were performed. The frequencies of these bands followed the Irving-Williams order in most cases and suggested the soft character of Fe(II) to sulfur atom. The values of isomer shift and quadrupole splitting of Mössbauer spectra in Fe(II) complexes of STTA revealed the contribution of π back-donation to a great extent.