Facets of Induced Internal Redox Involving WS42– and WSe42–: Synthesis and X-Ray Crystal Structures of syn-W2S2(μ-S)2(S2PPh2)2 and WO(Se2)(S2CNEt2)2

Abstract

Reaction of (NEt₄)₂[WS₄] and [S₂PPh₂]₂ in acetonitrile results in the formation of diamagnetic, orange syn-W₂S₂(µ-S) ₂(S₂PPh₂)₂ by an induced internal redox process. Crystals of the toluene solvate W₂S₂(µ-S) ₂(S₂PPh₂)₂ . C₇H₈ are triclinic and belong to space group P1– with a 13.845(5), b 16.536(7), c 8.387(2) Å, α 99.75(3), β 95.51(3), γ 83.08(3)˚, and Z 2. Refinement of 5445 data converged at R 0.038 and R_w 0.038. The complex possesses a syn-[W ^V ₂S₂(µ-S)₂]²⁺ core with a W–W bond of 2.8161(5) Å and two terminal W=S bonds of 2.097(3) and 2.096(3) Å. The W-(µ-S) bond distances are in the range 2.310(2)–2.315(2) Å. Each of the five-coordinate, square-pyramidal tungsten atoms is further coordinated by a bidentate dithiophosphinate ligand with W–S bond distances ranging from 2.464(2) to 2.481(2) Å. Extended reaction of (NH₄)₂[WSe₄] and [S₂CNEt₂]₂ in acetonitrile produces green WS(Se₂)(S₂CNEt₂)₂ and red WO(Se₂)(S₂CNEt₂)₂ in 40% and 15% yields, respectively. Crystals of WO(Se₂)(S₂CNEt₂)₂ are monoclinic and belong to space group P2₁/n with a 9.609(6), b 15.053(7), c 13.120(9) Å, β 100.08(4)˚, and Z 4. Refinement of 2473 data converged at R 0.039 and R_w 0.039. The seven-coordinate, pentagonal bipyramidal complex features C₁ symmetry, an axial oxo ligand (W=O 1.705(6) Å), an equatorial, side-on bonded diselenido ligand (W–Se(1) 2.509(1), W–Se(2) 2.547(1) Å, Se(1)–Se(2) 2.306(2) Å) and two bidentate dithiocarbamate ligands.