Preparation and spectral properties of a series of bis(phosphite) alkyne complexes and x-ray crystal structure of [WI2(CO){P(OMe)3}2(.eta.2-MeC.tplbond.CMe)]

The complexes [WI 2 (CO)(NCMe)(η 2 -RC 2 R) 2 ] (R=Me, Ph) react with 2 equiv of P(OR') 3 (R'=Me, Et, i Pr, n Bu) in CH 2 Cl 2 at room temperature to give the four-electron alkyne compounds [WI 2 (CO){P(OR') 3 } 2 (η 2 -RC 2 R)] via displacement of acetonitrile and an alkyne ligand, respectively. X-ray single-crystal crystallographic studies were carried out on the complex [WI 2 (CO){P(OMe) 3 } 2 (η 2 -MeC 2 Me)]. Crystals are orthorhombic, space group Pnab