Orbitally Nondegenerate Iron(III) Dithiocarbamates. I. Mössbauer Relaxation Phenomena

Abstract

Mössbauer investigations of (i) bis(N,N-diisopropyldithiocarbamato) iron (III) chloride, (ii) bis, (NN-diethyldithiocarbamato) iron (III) bromide, (iii) iron (III) trispyrrolidinedithiocarbamate, and (iv) bis(NN-diethyldithiocarbamato) iron (III) chloride are discussed. Compounds (i)–(iii) are paramagnetic. Their Mössbauer spectra show the presence of “nonadiabatic” relaxation effects which require for their interpretation the recent theories of Blume and Tjon, or Gabriel. For these compounds a single phenomenological relaxation rate constant C, representing electronic relaxation, was sufficient to characterize the temperature-dependent features in the spectra. The approximation of a single relaxation rate C is rigorously valid only in a polarized sample. The error involved in use of the method in paramagnetic samples is estimated from experiments in ferromagnetic compound (iv), where the value of C consistent with data for temperatures below TC (2.43°K) was found to be roughly one-third of the relaxation rate derived from data at higher temperatures.