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, IR spectra. The results reveal that these three complexes take mononuclear structures. And various weak interactions, including N-H···I and N···H-O H-bondings, 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.

本文以三种结构相关的配体——4-氨基-3-(3-吡啶基)-1H-1,2,4-三唑-5-硫酮(3-Haptt)、4-氨基-3-(4-吡啶基)-5-巯基-1,2,4-三唑(4-Haptt)与4-氨基-3-甲基-1,2,4-三唑啉-5-硫代二酮(a-Hmtt)——为底物，合成了三种新型二价汞配合物：[HgI₂(3-aptt)₂] (1)、[Hg(4-aptt)₂] (2)及[Hg(a-mtt)₂]·H₂O (3)。采用单晶X射线衍射技术测定了配合物1~3的晶体结构，并通过元素分析、红外光谱对其进行了进一步表征。研究结果显示，上述三种配合物均为单核结构。各类弱相互作用，包括N-H···I、N···H-O氢键，三唑环氮原子(N_trz)与吡啶环氮原子(N_py)间的相互作用以及π···π堆积作用，在晶体结构构建中发挥关键作用：正是这些弱相互作用将单核结构单元连接为高维超分子网络。本文还探讨了该系列配合物的热稳定性与固态发光性能。