摘要:
2-mercaptonicotinic acid (H(2)mna = 2-HS(C5H3N)COOH) gave a thiolato compound of the formula Hg(Hmna)(2) by a reaction with various mercury(II) salts, HgX2 (X = Cl-, Br-, I-, SCN-) in an ethanol or methanol solution irrespectively of the molar ratio of the reactants (1:1 or 1:2). The same compound was obtained from the reaction of mercury(II) acetate in an aqueous-ethanol solution. Hg(Hmna)(2) was characterized by vibrational spectroscopy and thermal analysis. H-1 and C-13 NMR measurements provided additional information on the thiol-thione tautomerism in H(2)mna and Hg(Hmna)(2) and also on the binding mode to mercury in the DMSO-d(6) solution. HgBr2(CH3-Hmna)(2) was obtained from the reaction of H(2)mna with HgBr2 in methanol after filtering off the main product Hg(Hmna)(2) (CH3-Hmna = 2-HS(C5H3N)COOCH3). The crystal structures of H(2)mna and HgBr2(CH3-Hmna)(2) were determined by the X-ray structure analysis. 2-mercaptonicotinic acid exists in the crystalline state in the thione tautomeric form. Two bromine atoms and two S-bound CH3-Hmna ligands form a tetrahedral coordination sphere around the mercury atom in HgBr2(CH3-Hmna)(2).(doi: 10.5562/cca2169)