PHOTOCHEMICAL-REACTION OF W(CO)(6) WITH SNCL4 .1. SYNTHESIS AND X-RAYSTRUCTURE OF LORO-TRICHLOROSTANNATE-HEPTACARBONYLDITUNGSTEN(II) [(CO)(4)W(MU-CL)(3)W(SNCL3)(CO)(3)]

The crystal structure of [(CO)(4)W(mu-Cl)(3)W(SnCl3)(CO)(3)] (1) forme d in the photochemical reaction of W(CO)(6) with SnCl4 was determined by the single-crystal X-ray diffraction method. The crystals are ortho rhombic, of space group Pbca, a = 12.706(3) Angstrom, b = 16.655(4) An gstrom, c = 18.669(3) Angstrom, V = 3951(2) Angstrom(3) and Z = 8. The structure solved by the heavy-atom method has been refined to R = 0.0 299 for 2187 observed reflections. The tungsten atoms in the molecule are both seven-coordinate, each being bonded to three bridging chlorin es, to four CO groups on one end and three CO groups and a SnCl3 group on the other. For each tungsten, there is a 4-3 geometry of ligand. N uclear magnetic resonance, IR and electronic absorption spectroscopies were used to examine the title compound. Compound 1 is a unique examp le of the halo carbonyls of Group 6 metals with an M-Sn bond.