Dithiolium and diselenolium compounds of the transition metals

Abstract

The preparations are reported of an extended series of compounds of the type ML₂X₄ where M is Mn, Fe, Co, or Ni; X is Cl or Br; and L is analytically identical with dithioacetylacetone.     Electronic, infrared, and Mossbauer spectra together with the temperature dependence of the magnetism (80-300°K) of these compounds establish-contrary to previous suggestions in the literature-that they should be properly formulated as tetrahalometallate salts of the 3,5- dimethyl-1,2-dithiolium cation. Simple salts of this cation (such as the iodide) have also been isolated.     During the course of this work salts (I- and [CoCl₄]^2-) of the hitherto unknown 3,5-dimethyl-1,2-diselenolium ion were synthesized and characterized for the first time.