Synthesis and Structural Assessment of Methyl 2-((4-phenyl-5-(pyridin-2-yl)-4H-1,2,4-triazol-3-yl)thio)acetate (phpy2NS) and its complex with HgCl₂.

Reaction of 2-cyanopyridine with N-phenylthiosemicarbazideafforded the 4-phenyl-5-(pyridin-2-yl)-2,4-dihydro-3H-1,2,4-triazole-3-thione. Methyl 2-((4-phenyl-5-(pyridin-2-yl)-4H-1,2,4-triazol-3-yl)thio)acetate (phpy2NS, 1), derived from this 1,2,4-triazole-3-thione, was obtained by reaction with chloroacetic acid followed by an acid-catalyzed esterification of the carboxylic acid with methyl alcohol. Synthesis of a Hg(II) complex, [Hg(phpy2NS)Cl₂] (2), has been performed using the ligand (1) and HgCl₂. The molecular and supramolecular structures of the ligand and the complex, were studied by X-ray diffractometry.