Thioacetate complexes of Group 12 metals. Structures of [Ph4P][Zn(SC{O}Me)3(H2O)] and [Ph4P][Cd(SC{O}Me)3]†
Abstract
The compounds [Ph4P][Zn(SC{O}Me)3(H2O)] 1 and [Ph4P][M(SC{O}Me)3] (M = Cd 2 or Hg 3) were synthesized by treating the appropriate metal salt with Et3NH+MeC{O}S– and Ph4PCl in the ratio 1∶3∶1 in water. The structures of 1 and 2 were determined by single crystal X-ray diffraction methods. In 1 the Zn is bonded to sulfur atoms of three thioacetate ligands and an oxygen atom of the H2O molecule to have an idealised tetrahedral geometry. The hydrogen atoms of the co-ordinated H2O molecule are involved in intramolecular O–H· · ·O hydrogen bonding with two carbonyl oxygen atoms. Approximate mirror symmetry is present in the anion. In the [Cd(SC{O}Me)3]– anion in 2 a propeller-like arrangement of the three co-ordinated MeC{O}S– is found. The three sulfur atoms are strongly bound to Cd giving a pyramidal CdS3 kernel. The anion is best described as having fac octahedral geometry with an approximate C3 symmetry. Metal NMR data have been measured for 2 and 3. The reduced temperature cadmium-113 NMR spectrum of a [Cd(SC{O}Me)3]––[Cd(SC{O}Ph)3]– mixture provides evidence for [Cd(SC{O}Me)x- (SC{O}Ph)3–x]– (x = 3–0), confirming the integrity of the two parent complexes in solution. Cadmium-113 NMR spectra of 2∶L mixtures (L = H2O, DMF or DMSO) show that [Cd(SC{O}Me)3]– is a weak acceptor. Mercury-199 NMR spectra of analogous 3∶L mixtures show that [Hg(SC{O}Me)3]– has, at best, a weaker acceptor ability towards H2O, DMF and DMSO than its cadmium analogue. The syntheses and metal NMR data show that the acceptor ability of [M(SC{O}Me)3]– (M = Zn to Hg) towards H2O varies with M in the order ZnII > CdII > HgII.