Synthesis, characterization, and electrochemical properties of a family of dinuclear rhodium complexes containing two terminal hydride ligands and two hydride (or chloride) bridges. Stoichiometric and catalytic hydrogenation reactions of alkynes and alkenes

Abstract

Protonation by strong acids and thermal decomposition in solution are two routes by which the trihydride (triphos)RhH/sub 3/ (triphos = MeC(CH/sub 2/PPh/sub 2/)/sub 3/) is used to synthesize the tetrahydrido complexes ((triphos)RhH(/mu/ - H)/sub 2/HRh(triphos)) (BPh/sub 4/)/sub 2/ and ((triphos)RhH(/mu/-H)/sub 2/HRh(triphos)). The characterization and electrochemistry of these complexes are reported, and their catalysis for hydrogenation reactions of dimethyl maleate and diethylacetylenedicarboxylate are discussed. The catalytic activity of the bimetallic species are compared with that of the mononuclear complexes. 17 refs., 5 figs., 2 tabs.