PHOTOCHEMICAL-REACTION OF W(CO)(6) WITH SNCL4 .2. SYNTHESIS AND X-RAY STRUCTURE OF TETRACHLOROBIS(TRIPHENYLPHOSPHINE OXIDE)TUNGSTEN(IV), [WCL4(OPPH(3))(2)]

The crystal structure of [WCl4(OPPh(3))(2)] (1), formed in the photochemical reaction of W(CO)(6) with SnCl4 in the presence of triphenylphosphine, has been determined by the single-crystal X-ray diffraction method. The compound crystallizes in the monoclinic space group C2/c, with a = 14.027(3), b = 13.163(3), c = 19.621(4) Angstrom beta = 96.36(3)degrees, Z = 4. The structure solved by heavy-atom methods has been refined to R = 0.0466, for 3489 observed reflections. The [WCl4(OPPh(3))(2)] molecule possesses a crystallographically imposed C-2 axis passing through the tungsten atom. Despite steric demands, a mutually cis arrangement of triphenylphosphine oxide oxygens is found for [WCl4(OPPh(3))(2)], while there is a slight lengthening of the W-Cl bonds trans to the oxygen atoms.