Syntheses and Reactions of Heterometallic Complexes of Nickel and Copper with Tetrathiotungstates. The Molecular Structures of [Ph4P]2[S2W(μ-S)2Ni(S2)] and W(μ-S)4Cu2(PPh3)4·py

Abstract

Reaction of [Ph4P]2WS4 with NiCl2 in methanol solution in the presence of NaOCH3 leads to the formation of [Ph4P]2 [S2W(μ-S)2Ni(S2)] (I). A similar reaction between (NH4)2WS4 and NiCl2 under O2 atmosphere in the presence of Ph4PCl or nBu4NCl affords [Ph4P]2{[(S2)W(O)(μ-S)2]2Ni} (Ila) and [ nBu4N]2{[(S2)W(O)(μ-S)2]2Ni} (lIb). Under argon the same reaction gives [Ph4P]2[Ni(WS4)2] (IlIa) and [nBu4N]2[Ni(WS4)2] (Illb). [Ph4P]2[Ni(WOS3)2] (IV) and [Ph4P]2[Ni(WO2S2)2] (V) can be prepared from the reaction of [Ph4P]2WOS3 and [Ph4P]2WO2S2 with NiCl2. Treatment of (NH4)2WS4 with CuCl in the presence of PPh3 in boiling pyridine produces W(μ-S)4Cu2(PPh3)3 (VI), which can further react with excess PPh3 to give W(μ-S)4Cu2(PPh3)4·py (VII). Complex I crystallizes in the space group P21/n with the cell parameters: a = 20.049(4), b = 17.010(4), c = 14.311(7) Å; β = 110.24(3)° and Z = 4; R = 0.058 for 4267 independent reflections. The structural study confirms that complex I contains two terminal sulfide ligands, two bridging sulfide ligands, a side-on disulfide ligand, and a planar central W(μ-S)2Ni four membered ring. Complex VII crystallizes in the space group C2/c with the cell parameters: a = 26.436(8), b = 20.542(6), c = 19.095(8) Å; β = 128.00(3)° and Z = 4; R = 0.080 for 3802 independent reflections. The structural study reveals a perfect linear arrangement of the three metal atoms Cu-W-Cu.