STUDIES OF TRINUCLEAR CADMIUM CLUSTER COMPLEXES. SYNTHESES AND CRYSTAL STRUCTURES OF [NMe4][Cd3(SC6H2Pr3i-2,4,6)7]°C5H12AND [Cd3(SC6H2Pr3i-2,4,6)6(HSC6H2Pri3-2,4,6)]·CH3OH·7H2O

Abstract

By the reaction of a sterically hindered arenethiol, 2,4,6-Prⁱ ₃C₆H₂SH, with Cd(NO₃)₂·4H₂O under different conditions, the colourless salt of trinuclear cadmium cluster anion complex [NMe₄][Cd₃(SC₆H₂Prⁱ ₃2,4,6)7]. C₅H₁₂ (1) and the uncharged trinuclear cadmium complex [Cd₃(SC₆H₂Prⁱ ₃2,4,6)₆(HSC₆H₂Prⁱ ₃2,4,6)]°CH₃OH·7H₂O (2) have been synthesized. These have in turn been structurally characterized. Crystals of (1) are monoclinic, space group P2₁ ln with a = 19.629(6), b = 25.608(9), c = 25.450(9)Å, β = 107.54(3)°, V- 12203(7)ų, Z = 4, R = 0.076 for 3839 observed reflections. Crystals of (2) are triclinic, space group P 1 with a = 19.792(10), b = 20.508(12), c = 33.97(2)Å, α = 85.81(5), β = 86.77(5), γ = 85.12(4)°, V = 13686(14)ų, Z = 4, R = 0.0921 for 8327 observed reflections. The core of the cluster anion of (1) [Cd₃(SC₆H₂Prⁱ ₃2,4,6)₇]⁻ is formed by a defect cubane unit with three cadmium and four sulphur atoms at its vertices. Each cadmium atom exhibits tetrahedral coodrination with one terminal sulphur, two doubly bridging sulphur and one triply bridging sulphur atoms. In complex (2), three cadmium atoms are coordinated by six thiolate (RS⁻) and one thiol (RSH) ligands. Two of three cadmium atoms have tetrahedral coordination and one is trigonal planar.