REACTIONS OF NiX2(dppe) (X = Cl, Br) WITH Na. SYNTHESIS AND CRYSTAL STRUCTURE OF Co2(μ-CO)2(CO)4(dppe) (dppe = Ph2PCH2CH2PPh2)

Article abstract of DOI:10.1016/S0022-328X(00)98758-8

The reaction of Na with NiX2(dppe) (X=Cl, Br; dppe=1,2-bis(diphenylphosphino)ethane) in THF or toluene at -30 to 0 deg C produces mainly Ni(CO)2(dppe) and Co2(CO)6(dppe).The structure of this latter complex, determined by an X-ray analysis, can be regarded as derived from that of Co2(CO)8 by substitution of two terminal CO groups on one cobalt atom by the chelating dppe ligand.This structure could not have been predicted unambiguously solely on the basis of the interpretation of the infrared data.Crystals of Co2(μ-CO)2(CO)4(dppe) are monoclinic, space group P2₁/a, with Z=4, in a unit cell of dimensions a 21.117(13), b 17.012(10), c 8.436(6) Angstroem, β 93.76(5)^o.The structure was solved by Patterson and Fourier methods and refined by full-matrix least-squares to R=0.053 for 1549 independent observed reflections.