Original scientific paper

https://doi.org/10.5562/cca2169

Synthesis, Spectral and Thermal Characterization of Bis(pyridine-3- carboxy-2-thiolato-S)mercury(II). Crystal Structure of Dibromobis(3- metoxycarbonylpyridine-2-thiolato-S)mercury(II)

Željka Soldin ; Division of General and Inorganic Chemistry, Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, HR-10000 Zagreb, Croatia
Dražen Vikić-Topić ; Ruđer Bošković Institute, NMR Centre, P. O. Box 180, HR-10002 Zagreb, Croatia
Gordana Pavlović ; Faculty of Textile Technology, Department of Applied Chemistry,University of Zagreb, Prilaz baruna Filipovića 28a, HR-10000 Zagreb, Croatia
Marijana Vinković ; Ruđer Bošković Institute, NMR Centre, P. O. Box 180, HR-10002 Zagreb, Croatia
Dubravka Matković-Čalogović ; Division of General and Inorganic Chemistry, Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, HR-10000 Zagreb, Croatia
Zora Popović ; Division of General and Inorganic Chemistry, Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, HR-10000 Zagreb, Croatia

Abstract

2-mercaptonicotinic acid (H2mna = 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. 1H and 13C NMR measurements provided
additional information on the thiol-thione tautomerism in H2mna and Hg(Hmna)2 and also on the binding
mode to mercury in the DMSO-d6 solution. HgBr2(CH3-Hmna)2 was obtained from the reaction of H2mna
with HgBr2 in methanol after filtering off the main product Hg(Hmna)2 (CH3-Hmna = 2-
HS(C5H3N)COOCH3). The crystal structures of H2mna 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)

Keywords

2-mercaptonicotinic acid; mercury complex; thione-thiol tautomerism; X-ray single crystal structure analysis; intra- and intermolecular hydrogen bonds; 1H, 13C NMR

Hrčak ID:

94450

URI

https://hrcak.srce.hr/94450

Publication date:

17.12.2012.

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