Hydride, Borohydride, and Dinitrogen Pincer Complexes of Ruthenium

Abstract

Reactions of chlorides RuCl(CO)(PCP) (1; PCP = [2,6-(CH2PBut2)2C6H3]-) and RuHCl[1,3-(CH2PBut2)2C6H4] (2) with [Bu4N]BH4 in ethanol afforded the hydrides RuH(CO)(PCP) (3) and [RuH(PCP)]2(μ-N2) (5a), respectively. Complex 5a exists in equilibrium with the dinitrogen species [RuH(N2)(PCP)](μ-N2)[RuH(PCP)] (5b) and RuH(N2)(PCP) (5c) in solution under N2. Reaction of 1 and [Bu4N]BH4 in ether resulted in formation of the two isomeric borohydride complexes Ru(η2-BH4)(CO)(PCP) (4a) and RuH(CO)[1-BH3-2,6-(CH2PBut2)2C6H3] (4b). Single-crystal X-ray structures of 3, 4b, and 5a,b are reported.