Mono- and dinuclear phosphine coordinated 1,4-bis(diphenylphosphino)ethyne seven-coordinate complexes of molybdenum(II) and tungsten(II)

Abstract

Equimolar quantities of the seven-coordinate compounds [MI 2(CO) 3(NCMe) 2] (M = Mo and W) and Ph 2PCCPPh 2 react in CH 2Cl 2 at room temperature to afford the Ph 2PCCPPh 2 phosphine coordinated bridged complexes [M 2I 4(CO) 6(μ-Ph 2PCCPPh 2) 2] in good yield. Reaction of [MI 2(CO) 3(NCMe) 2] with two equivalents of Ph 2PCCPPh 2 in CH 2Cl 2 at room temperature gives the mononuclear compounds [MI 2(CO) 3(Ph 2PCCPPh 2) 2]. 31P NMR studies show the Ph 2PCCPPh 2 ligand in [MI 2(CO) 3(Ph 2PCCPPh 2) 2] to have monodentate phosphine coordination.