HYDRIDO-COMPLEXES OF TRANSITION METALS. PART I. HYDRIDO-COMPLEXES OF RHODIUM(I), COBALT(I), AND COBALT(III)

The preparation and properties are described of complex-salts of rhodiumI, RhC2H4PPh222X X Cl, ClO4, BPh4. From these compounds, a very stable hydrido-complex of rhodiumI, RhHC2H4PPh222, was prepared by reduction with lithium aluminium hydride or sodium borohydride. The product of the reaction between CoBr2C2H4PP222 and sodium borohydride, previously described as a derivative of cobalt0, is shown to be a hydrido-complex of cobaltI, CoHC2H4PPh222. This formula is supported by the diamagnetism of the compound, by its infrared spectrum, and by its reaction with carbon tetrachloride to give chloroform. On the grounds of their dipole moments ca.3- 4D and of their isomorphism with NiC2H4PPh222, a non-orthogonal structure for these hydrido-complexes of rhodium and cobalt is suggested. The hydrido- complexs of cobaltI behaves like a Lewis base, giving with perchloric acid the hydrido-complexes CoH2C2H4PPh222ClO4.