Chelate complexes of molybdenum. I. Thiolo-bridged molybdenum(III) complexes with low magnetic moments

Abstract

Thiolo-bridged complexes of molybdenum(III) have been obtained from the reaction in alcohol of lithium hexachloromolybdate(III) enneahydrate with a number of chelating ligands containing a thiol group. These multinuclear complexes have three bridging groups--either three thiolo-bridges or two thiolo-bridges and one chloro-bridge-linking the molybdenum atoms which, except in one complex, are probably eight-coordinate, Only two complexes were obtained from the reaction of the ligands with potassium hexabromomolybdate(III) in alcohol. The bromo-derivatives were similar to but less stable than their chloro-analogues. All the complexes have anomalously low magnetic moments ranging from 0.3 to 1.56 BAT. per molybdenum atom, owing to metal-metal interaction either directly or via the bridging atoms. A monomeric five-coordinate molybdenum(1v) complex MoO[(PrⁱO)₂PS₂]₂ with a low magnetic moment (μ 0.9 B.M.) is also described.