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)A, 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)A, 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)A, 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).