Three coordination polymers constructed from a multidentate N-donor ligand, polycarboxylate anions and Zn(II)/Ag(I)/Mn(II) ions: synthesis, structures, characterization and pH-dependent photoluminescence

Abstract

Three new coordination polymers, namely {[Zn(5-OH-bdc)(2,4′-tmbpt)]·5H2O}n (1), [Ag3(L)(2,4′-tmbpt)2]n (2), and [Mn3(L)2(2,4′-tmbpt)2]n (3), have been prepared under hydrothermal condition (2,4′-tmbpt = 1-((1H-1,2,4-triazol-1-yl)methyl)-3-(4-pyridyl)-5-(2-pyridyl)-1,2,4-triazole, 5-OH-H2bdc = 5-hydroxy-1,3-benzenedicarboxylic acid, and L = 5-(4-carboxybenzyloxy)isophthalic acid). The structures of compounds 1–3 have been determined by single-crystal X-ray diffraction analysis. The structures of 1 and 3 have been characterized by elemental analysis, infrared spectra, powder X-ray diffraction analysis and thermogravimetric analysis. Compound 1 displays a 2D 4-connected sql net with the Schlafli symbol of (44·62), which is further connected by the intermolecular hydrogen bonds to generate a 3D supramolecular architecture. Compound 2 is a 3D two fold interpenetrating framework with the Schlafli symbol of (3·6·7)(32·83·9)(3·64·72·8·9·10). Compound 3 is a 3D (3,6,6)-connected framework with the Schlafli symbol of (3·62)(34·66·85)(33·68·83·10). The pH-dependent photoluminescent spectra of compound 1 have been investigated, and the pH-dependent photoluminescent mechanism has been discussed and proved by UV–Vis absorption spectra. Three compounds based on a multidentate N-donor ligand, Zn(II)/Ag(I)/Mn(II) ions and polycarboxylic acids have been synthesized under the hydrothermal conditions. The structures of these compounds have been characterized comprehensively. The pH-dependent photoluminescent spectra of compound 1 have been investigated. Moreover, the pH-dependent photoluminescent mechanism has been discussed and proved by UV–Vis absorption spectra.