Structural diversity and photoluminescent properties of zinc benzotriazole-5-carboxylate coordination polymers

Abstract

A series of zinc(II) compounds, [Zn2(btca)2(im) 2]·(DMA) (1; H2btca = benzotriazole-5-carboxylate acid, im = imidazole, and DMA = N,N-dimethylacetamide), [Zn(btca)(im)] ·(DMF) (2; DMF = N,N-dimethylformamide), [Zn2(btca) 2(tmdpy)]·2(DMF)·5(H2O) [3; tmdpy = 1,3-di(4-pyridyl)propane], and [H2N(CH3)2] 2[Zn3(btca)4]·(DMF) (4), have been successfully synthesized via rational control of experimental conditions. Single-crystal X-ray diffraction analyses indicate that compounds 1 and 2 are isomers, and both of them exhibit two-dimensional structures with the same uninodal 3-connected fes topology. Additionally, the three-dimensional (3D) structure of 3 was obtained by using tmdpy instead of an im ligand under synthesis conditions similar to those of compound 2. Interestingly, compound 3 presents a pillared-layer structure with a (3,4)-connected (4.8 2.103)(4.82) topology. When 4,4′-bipyridine was used to replace tmdpy, the assembly between Zn 2+ ions and H2btca ligands produced a chiral 3D framework of 4. Furthermore, compound 4 showed a new (3,4)-connected topology with a vertex symbol of (4.6.84)2(4.6.8)(4.82)(6. 82)2(6.85). A comparison of all compounds suggested that the structural diversity of the compounds could be tuned by altering the auxiliary ligand. In addition, the photoluminescent properties of compounds 1-4 were measured. © 2014 American Chemical Society.