SYNTHESES, REACTIVITIES AND MOLECULAR-STRUCTURES OF TUNGSTEN COMPLEXES CONTAINING THE DIPHENYLPHOSPHINODITHIOFORMATO LIGAND

Treatment of [NEt(4)][W(CO)(5)(PPh(2))] 1 with CS2 afforded [NEt(4)][W(CO)(5)(PPh(2)CS(2))] 3 which was also synthesized from the reaction of [W(CO)(5)(MeCN)] with [NEt(4)][PPh(2)CS(2)] 2. The reactions of 3 with various alkyl halides gave the neutral complexes [W(CO)(5){PPh(2)(CS(2)R)}] [R = Me(4a), Et, C2H4OH, C3H5, CH2CN, C2H4CN or C3H6CN], and the reactions of 3 with acyl halides gave [W(CO)(5){PPh(2)(CS2-COR)}] (R = Me or Ph). Both alkylation and acylation reactions occur at the sulfur atom. Treatment of 3 with [Re(CO)(5)Br] afforded [(OC)(5)W(mu-PPh(2)CS(2))Re(CO)(5)] in which the two metal atoms were bridged by the PPh(2)CS(2)(-) ligand. The reaction of 3 with [W(pip)(2)(CO)(4)] (pip = piperidine) yielded [W(CO)(5)(PPh(2)H)] and the dithiocarbamato tungsten complex [NEt(4)][W(CO)(4)(S2CNC5H10)]. Complex 3 reacted with organic alpha,omega-diiodides (CH2I2, C2H4I2, C3H6I2), giving the phosphine bridged dinuclear complexes [{(W(CO)(5)(PPh(2)CS(2))}(2)(mu-CH2)(n)] (n = 1-3), and only in the reaction of C3H6I2, was a mononuclear complex {[W(CO)(5){PPh(2)(CS2C3H6I)}]} seen as a minor product. Complex [{(W(CO)(5)(PPh(2)CS(2))}(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 [NEt(4)][W(CO)(4)(PPh(2)CS(2))]. 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 P2(1), a = 10.244(4), b = 9.877(4), c = 11.124(3) Angstrom, beta = 102.02(2)degrees, Z = 2, R = 0.062, R' = 0.073 based on 1180 reflections with l > 2 sigma(l); 3, triclinic, space group P (1) over bar, a = 10.688(3), b = 11.070(2), c = 12.785(2) Angstrom, alpha = 88.26(1), beta = 81.87(2), gamma = 74.081(17)degrees, Z = 2, R = 0.028. R' = 0.025 based on 4557 reflections with l > 2 sigma(l); 4a, triclinic, space group P (1) over bar, a = 9.177(5), b = 9.403(3), c = 12,461(6) Angstrom, alpha = 90.00(3), beta = 103,85(4), gamma = 94.79(3)degrees, Z = 2, R = 0.041. R' = 0.041 based on 2442 reflections with l > 20(l).