A diamond metal–organic framework with in situ generated 1H-tetrazolate-5-butyric acid ligand: Crystal structure, photoluminescence and high thermal stability

Hydrothermal reaction of diethyl 2-(2-cyanoethyl) malonate, ZnCl2, NaN3 and NaOH yielded a new 1H-tetrazolate-5-butyrate coordination polymer, [Zn(tzb)]n (1) (H2tzb = 1H-tetrazolate-5-butyric acid), which presents a 3-D noninterpenetrating diamond network. The in situ generated tzb2− ligand adopts a μ4-bridging mode with carboxylate group in a syn–anti fashion and tetrazolate group in a 1,4-N manner. Polymer 1 exhibits a weak second-order nonlinear optical coefficient about 0.5 times that of potassium dihydrogen phosphate (KDP), and also displays strong blue photoluminescence at room temperature and a high thermal stability up to 400 °C.