Pentacarbonyl(eta(2)-vinylferrocene)metal(0) complexes of Group 6 elements: synthesis and characterization

Photolysis of hexacarbonylmetal(0) complexes of the Group 6 elements in the presence of vinylferrocene in an n-hexane solution at -15 degreesC yields pentacarbonyl (eta(2)-vinylferrocene)metal(0) complexes as the sole photo-substitution product, different from the general reaction pattern observed for the same Group 6 metal carbonyls with other olefins. M(CO)(5)(eta(2)-vinylferrocene) complexes (M = Cr, Mo, W) could be isolated from the solution and characterized by using spectroscopic techniques. The complexes were found to be not very stable and their stability increases in the order Cr < Mo < W. The relatively stable W(CO)(5)(eta(2)-vinylferrocene) could be isolated as-a pure solid and characterized by elemental analysis, MS, IR and NMR spectroscopy, while the solid samples of the less stable Cr(CO)(5)(eta(2)-vinylferrocene) and Mo(CO)(5)(eta(2)-vinylferrocene) complexes were found to be contaminated with free vinylferrocene and characterized only by using IR and NMR spectroscopy