HYDRATION AND REDUCTION OF CARBON-DIOXIDE BY RHODIUM HYDRIDE COMPOUNDS - PREPARATION AND REACTIONS OF RHODIUM BICARBONATE AND FORMATE COMPLEXES, AND THE MOLECULAR-STRUCTURE OF RHH2(O2COH)(P(I-PR)3)2

Reaction of Rh(I) -hydride complexes RhH(P(i-Pr)3)3, RhH(N2)(PPh(t-Bu)2)2, and Rh2H2(μ-N2)(P(c-C6H11)3)4with CO2in the presence of H2O has been found to afford novel dihydrido bicarbonato complexes RhH2(O2COH)L2(1,L = P(i-Pr)3; 2, L = PPh(t-Bu)2; 3, L = P(c-C6H11)3). The crystal and molecular structure of 1 has been determined at -160°C. The complex RhH2(O2COH)(P(i-Pr)3)2(1) crystallizes in the monoclinic space group C2n-P21/c, with four formula units in a cell of dimensions a = 15.82 (1) Å, b = 10.88 (1) Å, c = I 5.49 (1) Å, β = 114.5 (1)°, V = 2428 Å3. In the solid state 1 consists of distorted octahedral Rh(lll) centers coupled by intermolecular hydrogen bonding between bicarbonato ligands. These dihydrido bicarbonato complexes, and analogous dihydrido formato complexes, reduce CO2to form Rh(l) carbonyl bicarbonato and formato complexes and H2O. © 1979, American Chemical Society. All rights reserved.