Synthesis, structure and solution NMR properties of (Ph4P)[M(SeC{O}Tol)3], M = Zn, Cd and Hg

Abstract

Metal selenocarboxylate salts (PPh₄)[M(SeC{O}Tol)₃] (M = Zn (1), Cd (2) and Hg (3); Tol = C₆H₄-p-CH₃) have been synthesized by reacting Zn(NO₃)₂·6H₂O, Cd(NO₃)₂·4H₂O or HgCl₂ with Na⁺TolC{O}Se⁻ and PPh₄Cl in the ratio of 1 ∶ 4 ∶ 1. The structures of these compounds were determined by single-crystal X-ray diffraction methods. The crystal structures contain discrete cations and anions. In the each anion, the metal center is bound to three TolC{O}Se ligands, primarily through Se, though some long M⋯O interactions also occur. NMR spectra (¹¹³Cd, ¹⁹⁹Hg and ⁷⁷Se, as appropriate) are reported for solutions of [M(SeC{O}Tol)₃]⁻, and of [M(SeC{O}Tol)₃]⁻–[M(SC{O}Ph)₃]⁻ mixtures (M = Zn–Hg), in CH₂Cl₂ at reduced temperatures. In addition, ESI-MS data have been obtained for [M(SeC{O}Tol)₃]⁻–[M(SC{O}Ph)₃]⁻ mixtures (M = Zn–Hg) in acetone and in CH₂Cl₂. The NMR and ESI-MS studies show that the complexes [M(SeC{O}Tol)_n(SC{O}Ph)_3−n]⁻ (n = 3–0) persist in solution.