Inorganic Chemistry, Vol.37, No.23, 6023-6029, 1998
Syntheses, crystal structures, spectroscopic characterization, and electrochemical studies of the ditungsten(III) complexes Cl3W(mu-L)(3)WCl3 and [Cl3W(mu-L)(2)(mu-Cl)WCl3](-) (L = 1,4-dithiane, 1,4-thioxane, pms = pentamethylene sulfide). C-S bond cleavage of the bridging thioether(s) in Cl3W(mu-L)(3)WCl3
Reduction of WCl4 with 1 equiv of sodium amalgam, in the presence of either a refluxing toluene or neat solution of the desired thioether, produces a mixture of Cl3W(mu-L)(3)WCl3 (L = 1,4-dithiane (1), 1,4-thioxane (2), pms = pentamethylene sulfide (3)) and [Na] [Cl3W(mu-L)(2)(mu-Cl)WCl3] (L = 1,4-dithiane (4), 1,4-thioxane (5), pms (6)). 4 and 5 could be converted to 1 and 2, respectively, in the presence of excess L in refluxing toluene. The structures of 1; 2, 3, 7, and 8 have been solved. 1, 2, and 3 are the first reported crystal structures for ditungsten(III) tris-bridged cyclic thioether complexes. Crystal data are as follows : for an acetone solvate of 1, monoclinic space group P2(1)/n (No. 14), a = 12.518(3) Angstrom, b = 9.475(2) Angstrom, c = 27.408(3) Angstrom, beta = 93.34(1)degrees, Z = 4; for an acetone solvate of 2, tetragonal space group P4/ncc (No. 130), a = 25.7603(3) Angstrom, b = 25.7603(3) Angstrom, c = 18.6771(2) Angstrom, Z = 16; for a hexane solvate of 3, monoclinic space group P2(1)/n (No. 14), a = 11.874(4) Angstrom, b = 21.823(3) Angstrom, c = 12.545(3) Angstrom, beta = 100.46(3)degrees, Z = 4; for an acetonitrile solvate of 7, monoclinic space group P2(1)/c (No. 14), a = 9.704(5) Angstrom, b = 28.241(7) Angstrom, c = 15.480(5) Angstrom, beta = 98.55(4)degrees, Z = 4; for a chloroform solvate of 8, monoclinic space group P2(1)/a (No. 14), a = 13.531(4) Angstrom, b = 25.207(5) Angstrom, c = 14.083(3) Angstrom, beta = 115.57(2)degrees Z = 4. 1, 2, and 3 were all shown to undergo C-S bond cleavage of a bridging thioether by reaction with [PPh4][Sptol] (ptol = 4-methyl phenyl) to afford the anionic complexes [PPh4][Cl3W(mu-S(CH2CH2)(2)E)(2)(mu-SCH(2)CH(2)ECH(2)CH(2)sptol)WCl3] (E = S (9), O (10), CH2 (12)). 1, 2, 7, and 8 undergo reversible one-electron reductions.