Zn(II)-formate Framework of mab topology: Synthesis from tea extract, electronic structure, and DNA-binding

Abstract

A new synthetic method for developing novel Metal Organic Frameworks(MOFs) of Zn(II) is reported here. Its formation is confirmed by single X-ray crystallography, FT-IR and UV-visible spectroscopy measurement. The polymeric (ZnC2H6O6)n (1) complex was synthesized from a mixture of tea extract, LiCl and zinc nitrate in DMF-Dioxane-H2O solvent. In contrast to the well-known perovskite-type Zn(II)-formate frameworks of pcu topology the resulting compound has topology of different 6-c net mab. Herein we studied the relations between structural characteristics of the less usual mab-type formate and properties. The origin of the formation of formate is not established but may form via the hydrolysis of DMF molecules. The oxidation state of Zn in the complex was +2 and confirmed by BVS calculation. The optical band gap of the polymeric complex was 5.2eV indicates its electronic properties. Density Function Theory (DFT) also justified the structural and electronic parameters of the complex. The bioactivity of the complex 1 has been established by the ability to bind CT-DNA with intercalation mode and the binding constant was Kb =1.74 × 102 M−1.