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

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.