Crystal structure of catena-poly[aqua-µ-1,4-benzenedicarboxylato-κ2O:O'-3,5-dimethyl-4-phenyl-1,2,4-triazole-κN-zinc(II)] monohydrate, Zn(H2O)(C8H4O4)(C10H11N3)·H2O, C18H17N3O6Zn

Abstract

Source of material Experimental detailsH atoms bonded to C atoms were placed geometrically and treated as riding, with C-H distances 0.93 Å and U iso (H) = 1.2 U eq (C) for the CH while U iso (H) = 1.5 U eq (C) for the CH 3 groups of L molecule. The H atoms of the water molecules were located from difference maps and refined with the O-H distances restrained to 0.82 Å and U iso (H) = 1.2 U eq (O). DiscussionThe rational design and construction of novel metal-organic frameworks (MOFs) are of current interest in the field of crystal engineering not only because of their promising applications in gas storage, separation, luminescence, heterogeneous catalysis and ion exchange, but also owing to their intriguing molecular architectures and topologies [1][2][3][4]. Generally, the multidentate organic ligands containing coordination sites of N donors such as triazole have favourable coordinate abilities and are widely utilized as building blocks in the construction of MOFs. The derivatives of 1,2,4-triazole can adopt the monodentate terminal or didentate N,N'-bridging coordination mode, which makes them easily link two adjacent metal ions to yield dinuclear, linear, trinuclear, or linear polymeric metal compounds with double or triple triazole bridges [5,6]. On the other hand, carboxylate ligands such benzenedicarboxylate, benzenetricarboxylate, biphenyldicarboxylate are most extensively studied organic ligands in the construction of MOFs due to their variable coordination modes, structural diversity, and thermodynamic stability. Particularly, the mixed ligands of polycarboxylate and N-containing are good candidates to yield novel MOFs with more tunable factors proved in our previous studies [7,8]. In this paper, we focus our attention on the reaction of mixed organic ligands containing 3,5-dimethyl-4-phenyl-1,2,4-triazole (L) and terephthalic acid ligands (H 2 pbda) and zinc ions to synthesize a new complex. In the structure of the title compound, each Zn II ion is 4-coordinated with a slightly distorted tetrahedral geometry, by three oxygen atoms (O2, O4, and O5) from two different pbda 2-ligands and one water molecule, and one nitrogen atom (N1) from the L ligand. The Zn-O distances range from 1.9337(15) to 2.0011(14) Å, while the Zn-N distance is 2.0291(17) Å. The Zn-N and Zn-O distances are comparable to those found in other crystallographically characterized Zn II complexes [9]. The pbda 2-ligands link Zn II ion ions using its carboxylate groups to form a 1D double chain, while the L ligands are terminal coordinated. It is worthwhile to note that hydrogen bonding interactions are usually important in the synthesis of supramolecular architec-Z. Kristallogr.