Electrochemical mechanism of CO2 reduction me diate d by NiII (tpa) (tpa = tris(2-pyridylmethyl)amine) complexes: An integral view

In this paper, we report the synthesis, characterization, as well as electrochemical, spectroelectrochemical, and density functional theory (DFT) calculations of a series of novel Ni-II complexes with a flexible tetradentate ligand, tris(2-pyridylmethyl)amine) (tpa). The complexes [Ni-II(tpa)(H2O)(MeCN)](BF4)(2), [Ni-II(tpa)(NO3)(2)], and [Ni-II(tpa)Cl-2] were studied for their ability to electrochemically reduce CO2. These complexes were compared with the tris-chelate complex [Ni(bpy)(3)](BF4)(2) to understand the role of flexible tetradentate ligands containing a pyridinic ring in the electrochemical reduction of CO2. Spectro-electrochemical experiments and theoretical studies were performed to rationalize the electrochemical reductions occurring and to predict the redox potential and pathway of CO2 reduction. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This paper reports the synthesis, characterization, and electrochemical studies of a series of novel Ni-II complexes, as well as the comparison with a tris-chelate complex to understand the role of flexible tetradentate ligands in CO2 reduction. Spectro-electrochemical experiments and theoretical studies were conducted to rationalize the electrochemical reductions and predict the pathway of CO2 reduction.