Bimetallic complexes of rhenium multihydrides with silver, copper or mercury containing diphosphine ligands

Abstract

Treatment of the rhenium pentahydride complex [ReH₅{P(C₆H₁₁)₃}₂(vdpp-P)][vdpp = Ph₂PC(CH₂)PPh₂], with silver iodide gives the fluxional complex [{(C₆H₁₁)₃P}₂H₃Re(µ-vdpp)(µ-H)₂Agl]; the Ph₂PCH₂PPh₂(dppm) complex [ReH₅{P(C₆H₁₁)₃}₂(dppm-P)] behaves analogously. Analogous complexes were prepared with CuCl or CuCN, e.g.[{(C₆H₁₁)₃P}₂H₃Re(µ-dppm)(µ-H)₂Cu(CN)]. The fluxionalities of these complexes were studied by ³¹P-{¹H} and ¹H-{³¹P} NMR spectroscopy over a range of temperatures. In contrast to the behaviour of silver iodide, copper(I) chloride or copper(I) cyanide, mercury(II) chloride reacts with [ReH₅{P(C₆H₁₁)₃}₂(dppm-P)] to give an adduct, apparently [HgCl₂{ReH₅[P(C₆H₁₁)₃]₂(dppm-P)}], in which the mercury is not complexed to the dppm but shows nuclear spin–spin coupling to the phosphorus atoms complexed to rhenium. The ³¹P-{¹H} and ¹H-{³¹P} NMR data are presented and discussed.