Three New Hg(II) Complexes Constructed From Mercapto- and Amino-Containing Triazole Ligands: Syntheses, Crystal Structures, and Luminescent Properties

Three new mercury(II) complexes [HgI₂(3-aptt)₂] (1), [Hg(4-aptt)₂] (2), and [Hg(a-mtt)₂]·H₂O (3) were synthesized based on three structurally related ligands: 4-amino-3-(3-pyridyl)-1H-1,2,4-triazole-5-thione (3-Haptt), 4-amino-3-(4-pyridyl)-5-mercapto-1,2,4-triazole (4-Haptt), and 4-amino-3-methyl-1,2,4-triazoline-5-thiadone (a-Hmtt). The structures of complexes 1–3 were determined by single-crystal X-ray diffraction techniques and further characterized by elemental analyses and IR spectra. The results reveal that these three complexes take mononuclear structures. And although various weak interactions, including N‒H···I and N···H‒O H-bondings as well as N_trz···N_py and π···π stacking, play significant roles in crystal structures, just these weak interactions link the mononuclear units into higher dimensional supramolecular networks. Their thermal stabilities and the solid state luminescent properties have also been discussed.