Syntheses, Crystal Structures And Anion Exchange Studies Of Coordination Polymers Containing N,N-2,6-Bis(4-Pyridylmethyl)Pyridine Dicarboxamide With Chromate Anion

Abstract

The release of hazardous anions such as chromate, nitrate and perchlorate into the waterways system has cause a destructive effect on human and the aquatic environment. To overcome this problem, many techniques utilizing amide compounds as anion receptors have been reported. New trend of using coordination polymers as anion receptors has attracted a lot of attention due to their large surface area and high selectivity. Therefore, in this study, a flexible U-shaped ligand with potential to bind anion, namely N,N-2,6-bis(4-pyridylmethyl)pyridine dicarboxamide (L1) has been successfully synthesized. This ligand was used as an organic linker in the construction of coordination polymers ({[Zn(L1)2(H2O)2](NO3)2.4H2O}n (MC1), {[Cd(L1)2(H2O)2](NO3)2.6H2O}n (MC2) and {[Cd(L1)2(H2O)2](ClO4)2.3 12 ⁄ H2O}n (MC3) which was purposely designed to selectively bind and separate anions, particularly chromate. All compounds were characterized using a combination of Fourier transform infrared (FTIR),113H and C Nuclear magnetic resonances (NMR) while the structure of the coordination polymers were confirmed by X-ray crystallography and elemental analysis.