MECHANISM OF (MU-H)(MU-ALKENYL)RE-2(CO)(8) FORMATION IN 350NM FLASH IRRADIATIONS OF RE-2(CO)(10)

The mechanism of (mu-H)(mu-alkenyl)Re-2(CO)(8) formation upon UV irrad iations of Re-2(CO)(10) in presence of olefin (styrene, trans-stilbene , 4-methyl-1-cyclohexane, and ethylene) was investigated by laser flas h photolyses. Such photoproducts result from reactions of the olefin w ith eq-Re-2(CO)(9). No reactions of Re(CO)(5) leading to hydride alken yl products were observed. Dependences of the reaction rate on olefin concentration and solvent revealed an additional intermediate formed a fter the addition of the olefin to eq-Re-2(CO)(9) and before the appea rance of the mu-hydrido-mu-alkenyl products.