CRYSTAL-STRUCTURE OF S(DIPHENYL-2-PYRIDYLPHOSPHINE-(P))TETRAIRIDIUM(0), [IR-4(CO)(8)(PPH(2)PYL)(3)]

The structure of the title tetranuclear cluster, C59H42N3O8P3Ir4, was determined by X-ray analysis. It crystallizes in the monoclinic space group C2/c. The unit cell parameters are: a = 47.277(6), b = 10.519(3) , c = 23.025(4) Angstrom, beta = 105.77(1)degrees. The iridium atoms f orm a nearly regular tetrahedron. Between Ir4 and N336 atoms exists a relatively strong bond, thus one of the phosphine ligands is bridging one coordinating via P and N atoms.