Structures and photoluminescence of zinc(ii) coordination polymers based on in situgenerated 1H-tetrazolate-5-propionic acid ligandsElectronic supplementary information (ESI) available: Additional structural figure of 1, PXRD patterns, TGA curves, excitation spectra and IR spectra for 1–3. CCDC reference numbers 815796–815798. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c1ce05281k

Hydrothermal reaction of ZnCl2, NCCH2CH2COONa and NaN3, in the absence/presence of auxiliary ligand 2,2′-bipy/4,4′-bipy, gave birth to three novel coordination polymers, namely, [Zn(tzp)]n(1), [Zn2(tzp)(N3)(OH)(2,2′-bipy)]n(2) and [Zn2(tzp)2(4,4′-bipy)]n(3) (H2tzp = 1H-tetrazolate-5-propionic acid). The tzp2−ligand was in situgenerated through the [2 + 3] cycloaddition reaction of nitrile and azide, which was first untilized to synthesize coordination compounds. Polymer 1behaves as a three-dimensional (3-D) network built up by the fusion of one-dimensional (1-D) pseudo-channels formed by the linkage of tzp2−ligands and tetrahedral Zn nodes. When the chelating 2,2′-bipy was introduced into the reaction system, a two-dimensional (2-D) puckered network 2was constructed, where 1-D pseudo-channels, similar to those in 1, are bridged by azide ions in an end-on (EO) mode. Employment of the linear bridging 4,4′-bipy ligand as the auxiliary ligand resulted in the formation of an unusual 3-D polymer 3, where the connection of Zn and tzp2−produces a 2-D network, which are further joined by 4,4′-bipy. The tzp2−ligands in 1–3show the flexible conformations and different coordination modes, with the tetrazolate group being the 1,4-Nmode and the carboxylate group being the syn–anti, syn–synand monodentate mode, respectively. The results suggest that the flexible nature of the tzp2−ligand as well as the introduction of auxiliary ligands is responsible for the formations of 1–3. Their photoluminescent properties and thermal stabilities have also been discussed. [ABSTRACT FROM AUTHOR]