Mechanism of a one-photon two-electron process in photocatalytic hydrogen evolution from ascorbic acid with a cobalt chlorin complex

Abstract

A one-photon two-electron process was made possible in photocatalytic H2 evolution from ascorbic acid with a cobalt(II) chlorin complex [Co(II)(Ch)] via electron transfer from ascorbate to the excited state of [Ru(bpy)3](2+) followed by electron transfer from [Ru(bpy)3](+) to Co(II)(Ch) with proton to give the hydride complex, which reacts with proton to produce H2. [Co(III)(Ch)](+) was reduced by ascorbate to reproduce Co(II)(Ch).

Understanding light-driven H2 evolution through the electronic tuning of aminopyridine cobalt complexes

“…This suggests that the rate-determining step of the overall catalytic process could involve a formation of a X–H bond, such as the protonation of Co I or Co II –H intermediates, to give Co III –H or hydrogen, respectively. 27 On-line MS studies provided further insights into the identification of the specific products generated during the light-driven catalysed processes ( Fig. 10 ).…”

Molecular Catalysts Immobilized on Semiconductor Photosensitizers for Proton Reduction toward Visible‐Light‐Driven Overall Water Splitting

“…Various molecules can be used as the photosensitizer, with Ir‐, Ru‐, and Co‐based complexes being widely recognized examples . Direct covalent linkage of a photosensitizing molecule with a molecular catalyst is another strategy for photocatalytic hydrogen generation, in which [Ru(bpy) 3 ] is often used for photosensitizing whereas a Co‐ or Ru‐based complex is common for the catalysis …”

Investigation of the intramolecular hydrogen bonding interactions and excited state proton transfer mechanism for both Br-BTN and CN-BTN systems

“…And it can also serve as an active site for initiating a plethora of chemical reactions due to the dynamic features of the proton. [7][8][9][10] As one of the most fundamental processes involved in biochemical and chemical reactions along with hydrogen bonding, proton transfer (PT) deserves the attention of vast numbers of scientists. [11][12][13][14][15] Various kinds of PT reaction have been identied and classied, such as reaction in the ground or excited states, adiabatic or nonadiabatic behaviors, and so on.…”