Effect of organic anions on the self-assembly of Zn(ii)-containing coordination polymers based on trigonal N-donor ligands

Abstract

A series of coordination polymers, namely, [Zn(2,3′-tmbpt)(o-bdc)(H₂O)] (1), [Zn(2,3′-tmbpt)(m-bdc)] (2), [Zn(2,3′-tmbpt)(p-bdc)]·H₂O (3), [Zn₂(2,3′-tmbpt)(btc)(OH)]·0.5H₂O (4), [Zn(2,3′-tmbpt)(btec)_0.5]·2H₂O (5), [Zn(3,3′-tmbpt)(o-bdc)]·H₂O (6), [Zn(3,3′-tmbpt)(m-bdc)(H₂O)]·H₂O (7), and [Zn₂(3,3′-tmbpt)(btc)(OH)(H₂O)] (8), where 2,3′-tmbpt = 1-((1H-1,2,4-triazol-1-yl)methyl)-3-(3-pyridyl)-5-(2-pyridyl)-1,2,4-triazole, 3,3′-tmbpt = 1-((1H-1,2,4-triazol-1-yl)methyl)-3,5-bis(3-pyridyl)-1,2,4-triazole, o-H₂bdc = 1,2-benzenedicarboxylic acid, m-H₂bdc = 1,3-benzenedicarboxylic acid, p-H₂bdc = 1,4-benzenedicarboxylic acid, H₃btc = 1,3,5-benzenetricarboxylic acid, and H₄btec = 1,2,4,5-benzenetetracarboxylic acid, have been synthesized under hydrothermal conditions. The structures of 1–8 have been determined by single-crystal X-ray diffraction analyses and were further characterized by infrared spectroscopy (IR), elemental analyses and powder X-ray diffraction (PXRD) analyses. Compounds 1 and 6 display 1D chain structures. Compound 2 shows a 3D 2-fold interpenetrating CdSO₄ framework. Compound 3 reveals a 2D 2-fold interpenetrating square layer (sql) structure. Compound 4 exhibits a 3D 2-fold interpenetrating framework with (6³)(6⁹·8) topology. Compound 5 shows a non-interpenetrating 3D framework with (8³)(8⁵·10) topology. Compound 7 has a 2D layer structure. Compound 8 displays a 3D 2-fold interpenetrating framework with (4·6²)(4²·6⁸·8⁵) topology. The structural discrepancies of compounds 1–8 imply that the organic anions play an important role in the formation of the resultant structures of the coordination polymers. The luminescent properties of compounds 1–8 have also been investigated.