Unexpected Redox Chemistry of P∩N- and As∩N-Rhenium(I) Tricarbonyl Complexes in the Presence of CO(2) Acting as an Acid

[Image: see text] This study reports on Re tricarbonyl complexes bearing 8-(diphenylphosphanyl)quinoline, P∩N, and 8-(diphenylarsanyl)quinoline, As∩N, as bidendate ligands. We studied the reactivity of these complexes in comparison with fac-Re(N∩N)(CO)(3)Cl (with N∩N = 2,2′-bipyridine or 4,4′-dimethyl-2,2′-bipyridine). We used a combination of electrochemical and spectroelectrochemical methods with time-resolved spectroscopy over 10 orders of magnitude (100 ps–1 s) to investigate the peculiar reactivity of one-electron-reduced Re(CO)(3)(P∩N)Cl and Re(CO)(3)(As∩N)Cl complexes also in the presence of protons.