LAUSR

In this work, a Zn(II)-containing coordination polymer, [Zn2(2,4′-tmbpt)2(o-bdc)2]·5H2O (1) [2,4′-tmbpt = 1-((1H-1,2,4-triazol-1-yl)methyl)-3-(4-pyridyl)-5-(2-pyridyl)-1,2,4-triazole and o-H2bdc = 1,2-benzenedicarboxylic acid] has been synthesized hydrothermally. The structure of the compound has been characterized by single crystal X-ray crystallography, elemental analysis, infrared spectra, thermogravimetric analysis and powder X-ray diffraction analysis. Compound 1 features a 2D layer structure formed by the cross-link of the wave-like chains and helical chains. Because the uncoordinated nitrogen atoms in compound 1 can bind H+, the luminescent spectra of compound 1 in aqueous solutions of different pH from 1 to 7 have been investigated. The result indicates that this compound can be used as a sensitive and efficient pH fluorescent sensor, which can be further used for the design of molecular logic gate in the narrow pH range of 2–3. The pH response mechanism of compound 1 may be the disturbance of the conjugated system resulting from the protonation of the 2,4′-tmbpt ligand in the compound, which has been proved by the UV-vis absorption spectra and density functional theory (DFT) calculation.