Construction of three new coordination polymers based on 5-ethyltetrazole (ET) generated via in situ cycloaddition reaction

Abstract

By the addition of different secondary ligands, three new d 10 metal coordination polymers, [M 2 (ET)(pzdc)(μ 3 -OH)] [M = Cd( 1 ), Zn( 2 )] and [Zn(Et)(Hbic)] (3) (ET = 5-ethyltetrazole; H 2 pzdc = Pyrazine-2,3-dicarboxylic acid; Hbic = 1H-benzimidazole-5-carboxylic acid), have been successfully prepared under hydrothermal reactions and structurally characterized by single-crystal X-ray diffraction analysis. The ET ligand in compounds 1–3 is in situ generated from the [2 + 3] cycloaddition reaction of the precursor propionitrile and NaN 3 in water with the aid of zinc/cadmium salt. Compounds 1 and 2 present three-dimensional (3D) (4,4,4,4)-connected net based on O-centered M 3 isosceles triangle. Compound 3 exhibits a 3D diamond framework constructed by infinite –ET–Zn–ET– 1D zigzag chains and Hbic as bridging coligand. Furthermore, the thermal stabilities of compounds 1–3 and the luminescence properties of compounds 1 and 2 have been investigated. Three new d 10 metal coordination polymers, [M 2 (ET)(pzdc)(μ 3 -OH)] [M = Cd( 1 ), Zn ( 2 )] and [Zn(ET)(Hbic)] (3) (ET = 5-ethyltetrazole; H 2 pzdc = Pyrazine-2,3-dicarboxylic acid; Hbic = 1 H-benzimidazole-5- carboxylic acid), have been successfully prepared under hydrothermal reactions and structurally characterized by single-crystal X-ray diffraction. ► Zinc/cadmium tetrazole-based coordination polymers have been synthesized. ► 5-ethyltetrazole ligand is in situ generated from the [2 + 3] cycloaddition reaction. ► Studies of luminescence properties of 1 and 2 indicate that they may be good blue-light emitting candidate materials.