117828-20-3Relevant academic research and scientific papers
Metal to ligand charge-transfer photochemistry of metal-metal-bonded complexes. 7. Photochemistry of (CO)4CoM(CO)3(bpy) (M = Mn, Re; bpy = 2,2′-bipyridine): Photocatalytic disproportionation of the manganese complex in the presence of PR3
Van Dijk, Hans K.,Van Der Haar, Jos,Stufkens, Derk J.,Oskam, Ad
, p. 75 - 81 (2008/10/08)
This article describes the photochemistry of the complexes (CO)4CoM(CO)3(bpy) (M = Mn, Re). Irradiation of the Mn complex in the absence of a nucleophile produced Mn2(CO)6(bpy)2. No such reaction was observed for the Re complex, although Re(CO)3(bpy) radicals could be detected by spin-trapping with tBu-?O. In the presence of PR3 or in a coordinating solvent (S), ionic photoproducts [M(CO)3(bpy)L]+[Co(CO)4]- (L = PR3, S) were formed. In the case of the Mn complex the reactions with PR3 appeared to be photocatalytic with quantum yields varying from 7 to 60 mol/einstein. When CBr4 was added to the above solutions, M(CO)3(bpy)Br was formed and all other reactions were suppressed. A remarkable reaction of the Re complex is its photodisproportionation in toluene at 230 K into the contact ion pair {Re(CO)3(bpy)+·Co(CO)4-}. This reaction was also completely suppressed by adding CBr4. The mechanisms of these reactions are discussed in terms of a homolytic cleavage of the metal-metal bond from the 3σσ* state, giving rise to the formation of a reactive 16-electron M(CO)3(bpy) radical species.
