Tetrathiometalate Complexes of Rhodium, Iridium, Palladium, and Platinum. Structures of [(C₅Me₅)RhCl]₂WS₄ and [(C₃H₅)Pd]₂WS₄

Synthetic routes to tetrathiometalate complexes of rhodium, iridium, palladium, and platinum are described. Acetonitrile solutions of WS₄^2- reacted with [Rh(diene)Cl]₂ (where diene = 1,5-cyclooctadiene (COD) or norbornadiene (NBD)), [Ir(COD)Cl]₂, [(η⁵-C₅Me₅)RhCl₂]₂, and [Pd(allyl)Cl]₂ to give good yields of μ-WS₄ complexes [Rh(diene)]₂WS₄, [Ir(COD)]₂WS₄, [(η⁵-C₅Me₅)RhCl]₂WS₄, and [(allyl)Pd]₂WS₄, respectively. (COD)PtCl₂ reacted with MS₄^2- to give (COD)PtMS₄, M = Mo, W. The latter complexes react further with PPh₃ or WS₄^2- to give (PPh₃)₂PtMS₄ and Pt(WS₄)₂^2-, respectively. [Rh(COD)]₂WS₄ reacted with t-BuNC to give [Rh(t-BuNC)₂]₂WS₄. RhCl₃·3H₂O and IrCl₃·H₂O react with WS₄^2- to give the octahedral complexes M(WS₄)₃^3- isolated as their Et₄N⁺ salts. The ¹⁸³W NMR spectrum of (Et₄N)₃[Rh(WS₄)₃] showed a doublet with J(¹⁸³W,₁¹⁰³Rh) = 4.8 Hz. Thermal gravimetric analyses of [Rh(COD)]₂WS₄ and (COD)PtWS₄ indicate that loss of organic coligands and stoichiometric amounts of sulfur occur at moderate temperatures. The compound [(η⁵-C₅Me₅)RhCl]₂WS ₄·CHCl₃ crystallizes in the orthorhombic space group P2₁2₁2₁ with a = 13.179 (2) Å, b = 28.725 (7) Å, c = 8.258 (2) Å, V = 3126 (2) ų, and Z = 4 and was refined to R = 0.052 and R_w = 0.059. The compound [(η³-C₃H₅)Pd]₂WS₄ crystallizes in the monoclinic space group P2₁/c with a = 9.230 (4) Å, b = 9.994 (5) Å, c = 14.780 (7) Å, β = 103.54 (4)°, V= 1325 (1) ų, and Z = 4 and was refined to R = 0.066 and R_w = 0.079.