Synthesis and Structures of Bis(alkene) Complexes of Tungsten and Molybdenum, [M(CO)2(dpphen)(dbf)2] (M = W or Mo; dpphen = 4,7-diphenyl-1,10-phenanthroline; dbf = dibutylfumarate)

Tungsten and molybdenum complexes [M(CO)(2)(dpphen)(dbf)(2)] (M = W 1 or Mo 2: dpphen = 4.7-diphenyl-1,10-phenanthroline-, dbf = dibutylfumarate) have been synthesized and structurally characterized by X-ray diffraction analysis. In both complexes which have similar structure, the metal atom co-ordination is distorted octahedral with dpphen and two CO groups in the equatorial plane and the metal atom binds in an eta (2)-fashion to the C-C bonds of two dbf ligands. The two C-C bonds are almost mutually orthogonal. The two complexes are different in conformation which result from face selection of the two dbf ligands for coordination to the metal atom.