Sulfur substitution in a Ni(cyclam) derivative results in lower overpotential for CO2 reduction and enhanced proton reduction

Gerschel, P. and Warm, K. and Farquhar, E.R. and Englert, U. and Reback, M.L. and Siegmund, D. and Ray, K. and Apfel, U.-P.

Volume: 48 Pages: 5923-5932
DOI: 10.1039/c8dt04740e
Published: 2019

The replacement of the opposing nitrogen atoms in 1,4,8,11-tetraazacyclotetradecane (cyclam) with two sulfur atoms in 1,8-dithia-4,11-diazacyclotetradecane (dithiacyclam) enables the electrochemical reduction of protons and CO2via the corresponding nickel(ii) complex at more positive potentials. In addition, a 10-fold enhancement in the proton reduction rate of [Ni(dithiacyclam)]2+ relative to [Ni(cylcam)]2+ was observed. The study provides vital insight into Nature's choice of employing predominantly sulfur based ligand platforms in achieving biological proton and CO2 reductions. © 2019 The Royal Society of Chemistry.

« back