A coordination polymer based on dinuclear (pyrazinyl tetrazolate) copper(ii) cations and Wells-Dawson anions for high-performance supercapacitor electrodes

Dalton Trans. 2017 Oct 17;46(40):13897-13902. doi: 10.1039/c7dt02230a.

Abstract

A new coordination polymer, (H2bpe)(Hbpe)2{[Cu(pzta)(H2O)][P2W18O62]}·5H2O (1) (pztaH = 5-(2-pyrazinyl) tetrazolate, bpe = bis(4-pyridyl)ethylene), was synthesized by the hydrothermal method. The structure was determined by single crystal X-ray diffraction analyses and further characterized by the SEM, EDS, BVS, FTIR, and PXRD techniques. In 1, the [P2W18O62]6- (P2W18) clusters as bidentate connectors link [Cu(pzta)(H2O)]24+ dinuclear copper(ii) complexes to form inorganic-organic chains. These chains and the [H2bpe]2+ counter-cations are fused together via hydrogen bonding to form a 3D supramolecular architecture. While 1 was employed as the electrode in a supercapacitor, the cycling stability (90.7% capacitance retention after 1000 circles) and specific capacitance (168 F g-1 at a current density of 5 A g-1) of the 1-based electrode are better than those of the parent α-K6P2W18O62-based electrode, demonstrating more outstanding electrochemical performances of 1. Besides, the 1-based electrode showed excellent electrocatalytic activities towards the reduction of H2O2 and KIO3.