New thiocarbonyl complexes of ruthenium

Abstract

Reaction of the complex [RuCl₂(CS)(PPh₃)₂]₂, (I), with MCl–HCl in acetone leads to chloride-bridge cleavage with formation of M[RuCl₃(CS)(PPh₃)₂](M = Ph₄As⁺, Ph₃(PhCH₂)P⁺, or Et₄N⁺), (II). Areinvestigation of the reaction between the complex [RuCl₂(PPh₃)₃] and CS₂ reveals that, in addition to the previously reported [RuCl(η-CS₂)(PPh₃)₃]Cl and (I), another thiocarbonyl complex, (III), with very similar physicochemical properties to (I) is also formed. Full analytical data and ³¹P n.m.r. studies, together with an X-ray crystallographic study, show that complex (III) is the tri-µ-chloro-species [(PPh₃)₂ClRuCl₃Ru(CS)(PPh₃)₂]. Although no evidence has been found for conversion of complex (I) into (III), prolonged shaking of an acetone solution of (I) gives a small amount of [(PPh₃)(CS)ClRuCl₃Ru(CS)(PPh₃)₂],Me₂CO, (IV). Reaction of complex (III) with concentrated hydrochloric acid gives paramagnetic [(PPh₃)Cl₂RuCl₃Ru(CS)(PPh₃)₂],2Me₂CO, (V), which contains ruthenium in formal oxidation states of (III) and (II).