Some iridium hydride and tetrahydroborate complexes with bulky tertiary phosphine ligands

Abstract

Iridium trichloride reacts with PBu^t₂Ph or PBu^t₃(L) in propan-2-ol to give five-co-ordinate dihydrides [IrClH₂L₂]. The complex [IrClH₂(PBu^t₂Ph)₂] reacts with sodium iodide to give [IrH₂I(PBu^t₂Ph)₂] or with carbon monoxide to give [Ir(CO)ClH₂(PBu^t₂)Ph)₂]. With dihydrogen and sodium propan-2-olate, [IrClH₂L₂] give the correspondlng pentahydrides [IrH₅L₂]. Hydrides of the type [IrCl_3–xH_x(PRBu^t₂)₂](a)x= 1, R = Me, or (b)x= 2, R = Bu^t react with sodium tetrahydroborate to give complexes [Ir(BH₄)H₂(PRBu^t₂)₂]. These are non-fluxionbl and have been characterized by ¹H, ³¹P, and ¹¹B n.m.r. spectroscopy. The complexes [Ir(BD₄)H₂(PBu^t₃)₂] and [Ir(BD₄)DH(PMeBu^t₂)₂] have also been prepared by Li[BD₄] reductions. The complex [Ir(BH₄)H₂(PMeBu^t₂)₂] decomposes slowly in deuteriotoluene to [IrH₅(PMeBu^t₂)₂] but [Ir(BH₄)H₂(PBut^t₃)₂] seems to be indefinitely stable.