Effects of proton tunneling distance on CO2 reduction by Mn terpyridine species

Abstract

Herein, we report two manganese terpyridine dicarbonyl complexes, covalently attached to a proximal (1) or distal (2) amide moiety at the ortho position of the pendent phenyl ring as a proton relay. The isomer 1 achieves a turnover frequency (TOF) of 325 s⁻¹ with a minor overpotential of ca. 200 mV. The performance ranks it among the most efficient molecular catalysts for CO₂-to-CO conversion, and it is ca.2 orders faster than isomer 2.