Complexation of 4,4′-di(tert-butyl)-5-ethynyl-2,2′-bithiazole with mercury(II) ion: Synthesis, structures and analytical applications

Two new mononuclear mercury(II) alkynyl complexes containing substituted bithiazole unit [R–Ctriple bond; length of mdashC–HgMe] (2) and [R–Ctriple bond; length of mdashC–Hg–Ctriple bond; length of mdashC–R] (3) (R = 4,4′-di(tert-butyl)-2,2′-bithiazol-5-yl) were prepared in good yields by mercuration of 4,4′-di(tert-butyl)-5-ethynyl-2,2′-bithiazole (1) at room temperature via the dehydrohalogenation reaction of MeHgCl and HgCl2 with terminal acetylene R–Ctriple bond; length of mdashCH. The structures of the title compounds were characterized by NMR and IR spectroscopy, FAB mass spectrometry, X-ray crystallography and luminescence spectra. A new protocol for derivatization of inorganic and organic mercury(II) ions to mono- and dialkynyl mercury(II) compounds followed by extraction into dichloromethane is suggested, which can be effectively analyzed by HPLC technique using UV detection. The proposed procedure can offer a new opportunity for the simultaneous determination of inorganic Hg(II) and MeHg(II) in aqueous solutions.