PARAMAGNETIC CARBONYL COBALT(II) COMPLEXES. MOLECULAR STRUCTURE OF BROMOCARBONYL-1,1,1-TRIS(DIPHENYLPHOSPHINOMETHYL)ETHANECOBALT(II) TETRAPHENYLBORATE

Article abstract of DOI:10.1016/S0022-328X(00)89875-7

Carbon monoxide or cyclohexyl isonitrile (L) react with the dinuclear five-coordinated derivatives of 1,1,1-tris(diphenylphosphinomethyl)ethane, (triphos), <(triphos)Co(μ-X)2Co(triphos)>(BPh4)2 (X=halide) to give complexes of formula <(triphos)Co(L)X>BPh4.The latter are rare examples of paramagnetic cobalt(II) carbonyl complexes.The molecular structure of <(triphos)Co(CO)Br)BPh4 has been determined from counter diffraction data.The crystals are monoclinic, space group P2₁/a with cell dimensions a 20.225(8), b 20.664(9), c 13.301(5); β 97.24(5) deg, D_c=1.338 gcm^-3 for Z=4.Full-matrix least squares refinement led to the conventional R factor of 0.057 for 3648 observed reflections.The molecular structure consists of five-coordinate <(triphos)Co(CO)Br>⁺ cations of intermediate geometry and BPh4^- anions.