Studies on solid state reactions of coordination compounds. XLVII. Solid state syntheses and crystal structures of cluster compounds {Cu₃MoS₃I} (PPh₃)₃S and {Cu₃WS₃Br} (PPh₃)₃S

Reactions of [NH⁴]₂[MS₄](M = Mo,W), CuX(X = Br, I) and PPh₃ in the solid state produced four mixed-metal sulfur containing clusters {Cu₃MS₃X}(PPh₃)₃S(M = Mo, W; X = Br, I), two of which (1: M = Mo, X = I; 2: M = W, X = Br) were structurally determined. Crystals of 1 and 2 are triclinic, space group P1 (1: a = 11.895(3), b = 13.107(1), c = 20.473(2)Å, α = 74.95(6), β = 84.87(8), γ = 64.27(7)°, Z=2, V=2776.1 ų, R_w = 0.064 for 6443 observed reflections. 2: a = 11.876 (1), b = 13.065 (2), c = 20.325(2)Å, α = 74.95(1), β= 85.39(1), γ = 64.09(1)°, Z = 2, V = 2737.3ų, R_w = 0.055 for ·5303 observed reflections). The results of the structure determination showed that the central units of the two cubane-like cluster compounds are composed of four metal atoms and four non-metal atoms situated at alternate corners. The differences of cubane-like cluster compounds obtained from solid state reactions and from solution reactions are discussed.