Syntheses, reactivities and molecular structures of tungsten complexes containing the diphenylphosphinodithioformato ligand

Abstract

Treatment of [NEt₄][W(CO)₅(PPh₂)]1 with CS₂ afforded [NEt₄][W(CO)₅(PPh₂CS₂)]3 which was also synthesized from the reaction of [W(CO)₅(MeCN)] with [NEt₄][PPh₂CS₂]2. The reactions of 3 with various alkyl halides gave the neutral complexes [W(CO)₅{PPh₂(CS₂R)}][R = Me(4a), Et, C₂H₄OH, C₃H₅, CH₂CN, C₂H₄CN or C₃H₆CN], and the reactions of 3 with acyl halides gave [W(CO)₅{PPh₂(CS₂COR)}](R = Me or Ph). Both alkylation and acylation reactions occur at the sulfur atom. Treatment of 3 with [Re(CO)₅Br] afforded [(OC)₅W(µ-PPh₂CS₂)Re(CO)₅] in which the two metal atoms were bridged by the PPh₂CS₂^– ligand. The reaction of 3 with [W(pip)₂(CO)₄](pip = piperidine) yielded [W(CO)₅(PPh₂H)] and the dithiocarbamato tungsten complex [NEt₄][W(CO)₄(S₂CNC₅H₁₀)]. Complex 3 reacted with organic α,ω-diiodides (CH₂I₂, C₂H₄I₂, C₃H₆I₂), giving the phosphine bridged dinuclear complexes [{W(CO)₅(PPh₂CS₂)}₂(µ-CH₂)_n](n= 1–3), and only in the reaction of C₃H₆I₂, was a mononuclear complex {[W(CO)₅{PPh₂(CS₂C₃H₆I)}]} seen as a minor product. Complex [{W(CO)₅(PPh₂CS₂)}₂(CO)₂] was obtained from the reaction of 3 with oxalyl bromide in CH₂Cl₂. Thermolysis of 3 in tetrahydrofuran (thf) gave an anionic product identified as [NEt₄][W(CO)₄(PPh₂CS₂)]. All of the complexes were identified by spectroscopic methods. The structures of complexes 2, 3, and 4a were confirmed by single-crystal X-ray diffraction analyses. Crystal data: 2, monoclinic, space group P2₁, a= 10.244(4), b= 9.877(4), c= 11.124(3)Å, β= 102.02(2)°, Z= 2, R= 0.062, R′= 0.073 based on 1180 reflections with l > 2σ(l); 3, triclinic, space group P, a= 10.688(3), b= 11.070(2), c= 12.785(2)Å, α= 88.26(1), β= 81.87(2), γ= 74.081(17)°, Z= 2, R= 0.028, R′= 0.025 based on 4557 reflections with l > 2σ(l); 4a, triclinic, space group P, a= 9.177(5), b= 9.403(3), c= 12.461(6)Å, α= 90.00(3), β= 103.85(4), γ= 94.79(3)°, Z= 2, R= 0.041, R′= 0.041 based on 2442 reflections with l > 2σ(l).