Flash photolysis of CpMn(C0)3, CbFe(C0)3 and ArCr(C0)3 in alkane solvents, resulted m the immediate formation of the solvent substituted dicarbonyl species. The reactivity of these species were investigated by uv/vis flash photolysis studies and in the case of CpMn(C0)3 by tnr flash photolysis. The rate constants for the reaction of theses species with a variety of nucleophiles were determined and the thermodynamic parameters associated with these reactions were measured. The chelation reactions of chromium carbonyl complexes, containing multidentate ligands, were investigated by uv/vis and ir spectroscopy. These chelation reaction were seen to proceed via bridging intermediates, even in those cases where the initial complex was coordinated in a monodentate fashion. The crystal structures of a number of chromium and tungsten complexes were determined and correlated with their spectroscopic features.