Photochemical decomposition of h3-allyl complexes of transition metals

Photolysis of h3-allyl derivatives of tungsten and molybdenum has been studied. To obtain data on stereo-and regioselectivity of the decay, complexes have been chosen with assymmetric allyl ligands (predominantly h3-crotyl). For tungsten (7) and molybdenum (8) complexes typical is the smaller content of the products of doubling of crotyl fragments than for (h3-C4H7)2Ni and an increased yield of butenes; tetra-(h3-crotyl)-tungsten liberate cis and trans-butenes-2 in equal amounts. High stereo- and regioselectivity points to the absence of free-radical stages of transformation