REACTIVITY OF F-D HETEROBINUCLEAR VS, D-METAL-COMPLEXES - ASSISTED ORIMPEDED CATALYSIS - EVIDENCE FOR THE FORMATION OF STABLE CHLORO-BRIDGED HETEROBIMETALLIC SPECIES - SYNTHESIS OF RUH(2)PPH(3)[(C(5)ME(4)PME(2))(2)ZRCL2]

The hydrogenation of hex-1-ene was studied in THF and toluene solution in the presence of H2Ru(PPh(3))(4) 1 modified by the addition of the uranium and neodymium chlorides. A significant increase in the catalyt ic activity of 1 has been found to be due to the formation of hydrochl oride HClRu(PPh(3))(3) 2. Addition of a 1:1 NdCl3(THF)(3)/dppmO mixtur e or (C(5)H(4)(t)Bu)(2)NdCl and (C(5)H(4)PPh(2))(3)UCl resulted in the loss of catalytic activity of 1, indicating the formation of unreacti ve species from 1. The new stable bimetallic complex H2Ru(PPh(3))(Me(2 )PC(5)Me(4))(2)ZrCl2 5 was obtained from H-2(H-2)Ru(PPh(3))3 and (Me(2 )PC(5)Me(4))(2)ZrCl2. The presence of a Zr-Cl-Ru bridging bond was est ablished in 5 from H-1, P-31 NMR and H-1 NMR relaxation data. Such str ong early-late chloro-bridged binuclear structures could rationalize t he loss of catalytic activity of 1. An unexpected catalytic activity o f 2 was found in the hydrogenation of internal olefins. It has been sh own that complex 2 also hydrogenates internal olefins quite quickly in THF and toluene solution.