Facets of induced internal redox involving WS42- and WSe42- : synthesis and X-ray crystal structures of syn-W2S2(mu-S)(2)(S2PPh2)(2) and WO(Se-2)(S2CNEt2)(2)

Reaction of (NEt4)(2)[WS4] and [S2PPh2](2) in acetonitrile results in the f ormation of diamagnetic, orange syn-W2S2(muS) (2)(S2PPh2)(2) by an induced internal redox process. Crystals of the toluene solvate W2S2(mu -S)(2)(S2PP h2)(2) C7H8 are triclinic and belong to space group P (1) over bar - with a 13.845(5), b 16.536(7), c 8.387(2), alpha 99.75(3), beta 95.51(3), gamma 8 3.08(3)degrees, and Z 2. Refinement of 5445 data converged at R 0.038 and R -w 0.038. The complex possesses a syn-[(W2S2)-S-V(mu -S)(2)](2+) core with a W-W bond of 2.8161(5) and two terminal W=S bonds of 2.097(3) and 2.096(3) . The W-(mu -S) bond distances are in the range 2.310(2)-2.315(2) . Each of the five-coordinate, square-pyramidal tungsten atoms is further coordinate d by a bidentate dithiophosphinate ligand with W-S bond distances ranging f rom 2.464(2) to 2.481(2). Extended reaction of (NH4)(2)[WSe4] and [S2CNEt2] (2) in acetonitrile produces green WS(Se-2)(S2CNEt2)(2) and red WO(Se-2)(S2 CNEt2)(2) in 40% and 15% yields, respectively. Crystals of WO(Se-2)(S2CNEt2 )(2) are monoclinic and belong to space group P2(1)/n with a 9.609(6), b 15 .053(7), c 13.120(9), beta 100.08(4)degrees, and Z 4. Refinement of 2473 da ta converged at R 0.039 and R-w 0.039. The seven-coordinate, pentagonal bip yramidal complex features C-1 symmetry, an axial oxo ligand (W=O 1.705(6)), an equatorial, side-on bonded diselenido ligand (W-Se(1) 2.509(1), W-Se(2) 2.547(1), Se(1)-Se(2) 2.306(2)) and two bidentate dithiocarbamate ligands.