Electrocatalytic proton reduction catalyzed by a dimanganese disulfide carbonyl complex containing a redox-active internal disulfide bond

Abstract

A dimanganese hexacarbonyl complex [(Mn(CO)3)2(μ-SC6H4-o-S-S-C6H4-o-μ-S-)] containing an elongated disulfide bond electrocatalyses proton reduction at moderate overpotentials of 0.55 to 0.65 V. Cyclic voltammetric, infrared spectroscopy and computational studies suggest that the redox-active sulfur atoms of the disulfide bond serve as the initial reduction site.

Dinuclear Manganese Carbonyl Complexes: Electrocatalytic Reduction of Protons to Dihydrogen

“…Since the report on the first structure of the [FeFe] hydrogenase enzyme active site, numerous complexes based on earth‐abundant metals cobalt, nickel and iron have been reported as photo‐ and electrocatalysts for the hydrogen evolution reaction (HER) . While several Mn electrocatalysts have been developed for CO 2 reduction, very few catalysts have been developed for HER . This is surprising because: (i) Mn is also considered as one of the most abundant metals on earth, (ii) it is a desirable element for sustainable catalytic transformations, (iii) it has the capability to be stable in different oxidation states thus allowing redox reactions to be carried out in a facile manner, and (iv) the Mn I (CO) 3 moiety is isolobal with the Fe II (CO)(CN) 2 unit present in the [NiFe] H 2 ase active site.…”

“…This is surprising because: (i) Mn is also considered as one of the most abundant metals on earth, (ii) it is a desirable element for sustainable catalytic transformations, (iii) it has the capability to be stable in different oxidation states thus allowing redox reactions to be carried out in a facile manner, and (iv) the Mn I (CO) 3 moiety is isolobal with the Fe II (CO)(CN) 2 unit present in the [NiFe] H 2 ase active site. So far the Mn complexes reported as electrocatalysts include both mononuclear and dinuclear systems (Figure ) . Mostly dinuclear manganese complexes have been investigated as catalysts for the HER.…”

Sulfur‐Containing Molecules Grafted on Carbon Nanotubes as Highly Cyclable Cathodes for Lithium/Organic Batteries

“…The first reduction peak can be assigned to the one‐electron reduction of the disulfide bond to the radical anion. The second peak can be attributed to the reduction of the radical anion in a dianion by a second electron ,. This signal confirms both the grafting and the electrochemical activity of molecules on the nanotubes.…”

“…The second peak can be attributed to the reduction of the radical anion in a dianion by a second electron. [48,49] This signal confirms both the grafting and the electrochemical activity of molecules on the nanotubes. It is worth mentioning that the CV of functionalized MWNTs 7 performed in coin cell does not permit to observe the two oxidation and reduction peaks and only broad peaks are observed ( Figure S2).…”

Electrocatalytic Dihydrogen Production by an Earth-Abundant Manganese Bipyridine Catalyst

“…The η for 1, although far from ideal, is comparable to many previously reported HER electrocatalysts. 4,15 The peak-shaped current response in our catalytic CVs can be attributed to a variety of "side-phenomena" that cause local perturbations in the diffusion layer and have been previously discussed. 16 Additionally, peak-shaped current responses are typical for electrocatalysis involving TFA due to issues involving homoconjugation.…”