Hydrothermal syntheses, crystal structures, and fluorescent properties of Zn(II) coordination complexes with 4-amino-3,5-bis(2-pyridyl)-1,2,4-triazole and different aromatic dicarboxylic acids

摘要

Three new Zn(II) supramolecular complexes {[Zn(2- bpt)(tp)(H _2O)](H2O)} _∞ (1), [Zn(2-bpt) _2(Hpa) _2] (2), and [Zn(2- bpt) _2(H _2O) _2](Hip-NO _2) _2 (3) have been synthesized under hydrothermal conditions by using 4-amino-3,5-bis(2-pyridyl)- 1,2,4-triazole (2-bpt) and Zn(OAc) _2 with the presence of different aromatic dicarboxylic acids (H 2tp = terephthalic acid, H _2pa = phthalic acid, and H _2ip-NO _2 = 5-nitroisophthalic acid). Complex 1 shows a one-dimensional zigzag chain array, 2 represents a neutral mononuclear molecule, and 3 consists of the cationic mononuclear coordination unit and Hip-NO _2 anion. Notably, in complex 3, the H _2ip-NO _2 ligand is partly deprotonated to balance the charge and uncoordinated to the metal center. In all three structures, the low-dimensional coordination motifs are further extended to distinct two-dimensional or three-dimensional supramolecular networks via H-bonding and/or π···π stacking interactions. Fluorescent properties for 1-3 have also been studied in solid state at room temperature.