SYNTHESIS AND MOLECULAR STRUCTURE OF NOVEL BINUCLEAR COBALT COMPLEX WITH MIXED VALENCE STATE Co（Ⅰ）Co（Ⅱ） （μ-Ph2Ppy）2（μ-CO）2Cl3

A novel binuclear cobalt complex with mixed valence state Co（Ⅰ）Co（Ⅱ）（μ-Ph2Ppy）2（μ-CO）2Cl3 has been prepared, Ph2Ppy=2-（diphenyl phosphino）pyridine, and its molecular structure determined by using 3569 independent reflections. The complex was crystallized in the orthorhomblc space group P21nb with a=13.32（1）, b=14.31（1）,c=18.94（2） and Z=4. The structure was solved by direct method and full-matrix least squares refinement carried out. The final R value is 0.072.If the Co-Co bond is not taken into account, two cobalt atoms exhibit a five-coordlnate reformed trigonal bipyramid configuration （formal oxidation state +1） and a six-coordinate reformed octahedral configuration （formal oxidation state +2）, respectively. The Co-Co distance is 2.685（1）. The molecule belongs to the C2v, point group. A new W-frame compound with mixed valence state Co（0）Co（Ⅰ）（μ-Ph2Ppy）2（μ-CO）（CO）Cl can be formed by reducing this complex.