Synthesis and structural characterization of osmium cluster complexes containing 2-phenylazopyridine. Crystal structures of [Os 3(CO) 10(NC 5H 4NNC 6H 5)] and [Os 3(CO) 10(μ-H)(NC 5H 3NN(O)C 6H 5)

Abstract

The reaction of [Os 3(CO) 10(MeCN) 2] with 2-phenylazopyridine (2-PAP) affords [Os 3(CO) 10(NC 5H 4NNC 6H 5)] ( 1), [Os 3(CO) 10(μ-H)(NC 5H 3NN(O)C 6H 5)] ( 2) and a violet product 3, which is an isomer of 1. In 1, the 2-PAP moiety acts as the rarely observed six-electron donor. Cluster 2 contains an ‘oxidized’ 2-PAP moiety bonding in the usual ortho-metallated mode of pyridine. Both clusters 1 and 2 have been fully characterized in solution by conventional spectroscopic methods and in the solid state by single crystal X-ray diffraction analysis. Crystals of 1 are orthorhombic, space group P2 12 12 1, Z = 4, with unit cell dimensions a = 9.123(1), b = 17.217(2), c = 16.168(2) A ̊ . Crystals of 2 are triclinic, space group P 1, Z = 2 , with unit cell dimensions a = 9.308(2), b = 11.250(2), c = 12.934(2) A ̊ , α = 77.23(1), β=72.26(1), γ=85.21(1)° .