Ligandenmangelkomplexe des Cadmiums. Synthese und spektroskopische Charakterisierung molekularer (Pentafluorphenyl)cadmium-Thiolate und die Struktur des Cubankomplexes [{Cd(C6F5)(SBut)}4] / Ligand-Deficient Complexes of Cadmium. Synthesis and Spectroscopic Characterization of Molecular Pentafluorophenyl Cadmium Thiolates and the Structure of the Cubane Complex [{Cd(C6F5)(SBut)}4]

Abstract

Abstract In toluene, bis(pentafluorophenyl)cadmium(II) and thiols RSH (R = But, 2,4,6-Pri 3C6H2, 2,4,6-But 3C6H2) react to give soluble pentafluorophenyl cadmium thiolates [(Cd(C6F5)(SR)}n] The compounds [{Cd(C6F5)(SBut)}4] (1) ∙ 0.5 C6H5CH3, [ {Cd(C6F5)(SC6H2Pri 3-2,4,6)}n ] (2) ∙ ca. 0.25n C6H5CH3, and [{Cd(C6F5)(SC6H2But 3-2,4,6)} n] (3) ∙ ca. 0.25 n C6H5CH3 have been prepared in 65, 59 and 78% yield, respectively. 1 ∙ 0.5 C6H5CH3 crystallizes in the triclinic space group P1̄ with a = 11,635(1)Å, b = 11.583(1)Å, c = 21.480(2)Å, α = 82.12(1)°, β = 76.26(1)°, γ = 89.35(1)°, and Z = 2. 1 is a cubane-type complex with a {Cd4(μ3-SBut)4}4+ core. Each Cd atom is coordinated by three bridging thiolato ligands and one terminal C6F5 group (Cd - S 2.62 Å, Cd - C 2.15 Å (mean values)). The central C atoms of the ButS− ligands of 1 show a remarkable low-field shift o f their 13C NMR resonance (12.3 ppm relative to the value of the free thiol). A characteristic spectral feature of (Cd(C6F5) }+ complexes is the large value of the coupling constant 2J (19F ,13C) of the ipso-C atom (1, 2: 68 Hz; 3: 67 Hz). The complexes [Cd(C6F5)(SR) + H]+, [Cd(SR)2 + H]+, and [Cd2(SR)3]+ were identified in the Cl mass spectra (iso-butane) of 2 and 3.