SYNTHESIS AND STRUCTURE OF A SERIES OF UNIQUE COBALT PHOSPHIDES

The reaction of CoCl2 and [CoCl(PMe3)3] with the phosphidophosphine LiP(CH2CHPMe2)2 afforded a unique class of cobalt phosphido complexes, revealing a new mode of reactivity for this ligand. The solid-state structure of the first monomeric cobalt phosphido complex, [Co{P(CH4CH2-PMe2)2}{[P(CH2CH2PMe2)2],}] 1 has been determined: monoclinic, space group P2(1)/c, a = 15.484(7), b = 13.947(6), c = 17.875(2) angstrom, beta = 108.54(2)-degrees. An analogue, [Co{P(CH2CH2PMe2)2}(Me2PCH2-CH2PMe2)] 2, has been characterised by P-31-{H-1} NMR spectroscopy. Complex 1 was shown to be fluxional in solution and further characterised by two-dimensional correlation P-31-{H-1} NMR spectroscopy. The corresponding spectrum of 2 interestingly shows no 2J(P-P) coupling via the cobalt centre.