RHODIUM COMPLEXES HRH[P(NC4H4)(3)](4) AND HRH(CO)[P(NC4H4)(3)](3) AS ACTIVE CATALYSTS OF OLEFINS AND ARENES HYDROGENATION - X-RAY STRUCTUREOF HRH(CO)[P(NC4H4)(3)](3)

The rhodium hydride complexes HRh[PPhx(NC4H4)(3-x)](4) (x = 0-2) and H Rh(CO)[PPhx(NC4H4)(3-x)](3) have been obtained in reactions of Rh(acac )(CO)(2) + PPhx(NC4H4)(3-x) with H-2 or H-2/CO (0.1 MPa, room temperat ure) respectively. The crystal structure of HRh(CO)[P(NC4H4)(3)](3) ha s been determined. The complex is slightly distorted trigonal bipyrami dal with H and CO ligands occupying the axial positions. The Rh atom i s located 0.336 Angstrom out of plane of the three equatorial P atoms. The Rh-H distance in two crystallographically independent molecules i s 1.51(5) and 1.69(6) Angstrom respectively. The complexes HRh[P(NC4H4 )(3)](4) and HRh(CO)[P(NC4H4)(3)](3) are active catalysts of hydrogena tion reaction of olefins and arenes (cyclohexene, 1,3-cyclohexadiene, 1,4-cyclohexadiene, propenylbenzene, styrene, toluene) at 353 K and 0. 5 MPa H-2. The TOF up to 836 mol/mol Rh per h have been obtained. (C) 1998 Elsevier Science S.A.