Photoinduced Hydrogen Evolution Catalyzed by Co(II) Complexes of N5‐Donor Ligands

Three new cobalt complexes of the general formula [Co(II)(L)(CH<sub>3</sub>CN) ]<sup>2+</sup>, where L is one of three pentadentate nitrogen-donor ligands based on the N4Py framework, have been synthesized and characterized. The capacity of the three complexes to effect photocatalytic proton reduction has been examined. Their photocatalytic activities in the presence of [Ru(bpy)<sub>3</sub>]<sup>2+</sup>, acting as a photosensitizer, and ascorbic acid, acting as a sacrificial electron donor, were screened in a water/acetonitrile mixture. The photochemical mechanism, as revealed by nanosecond time-resolved transient absorption spectroscopy, involves reaction of the excited sensitizer with ascorbic acid to yield [Ru(bpy)<sub>3</sub>]<sup>+</sup> as a primary photogenerated reductant, capable of electron transfer to the cobalt catalyst(s). Under the experimental conditions used, partial decomposition of both the sensitizer and the catalyst is the main deactivation channel for photocatalysis. Optimization of reaction conditions indicated that the use of more reducing iridium or copper-based photosensitizers had a beneficial effect on the catalytic performance. The effect of the different ligands on the catalytic activities of the corresponding cobalt complexes have been investigated by DFT calculations.

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Journal
Chemistry - A European Journal
Published
2025-02-21
DOI
https://doi.org/10.1002/chem.202404499
Citations
1
Primary Topic
Metalloenzymes and iron-sulfur proteins
Type
article
Field-Weighted Citation Impact
0.36

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article

Photoinduced Hydrogen Evolution Catalyzed by Co(II) Complexes of N5‐Donor Ligands

Matti Haukka, Chuanshuai Li, Julio Lloret‐Fillol, Ebbe Nordlander et al.
1 citations
Chemistry - A European Journal
Metalloenzymes and iron-sulfur proteins
0.36
article

Photoinduced Hydrogen Evolution Catalyzed by Co(II) Complexes of N5‐Donor Ligands

Matti Haukka, Chuanshuai Li, Julio Lloret‐Fillol, Ebbe Nordlander, Fatma M. Elantabli, Iria Bolaño Losada, Petter Persson, Yusen Luo, Derek A. Tocher, Klaudia Michaliszyn, Meiyuan Guo, Md. Kamal Hossain, Benjamin Dietzek‐Ivanšić, Lintang Hizbullah, Yong Li
article en
1 citations

Abstract

Three new cobalt complexes of the general formula [Co(II)(L)(CH<sub>3</sub>CN) ]<sup>2+</sup>, where L is one of three pentadentate nitrogen-donor ligands based on the N4Py framework, have been synthesized and characterized. The capacity of the three complexes to effect photocatalytic proton reduction has been examined. Their photocatalytic activities in the presence of [Ru(bpy)<sub>3</sub>]<sup>2+</sup>, acting as a photosensitizer, and ascorbic acid, acting as a sacrificial electron donor, were screened in a water/acetonitrile mixture. The photochemical mechanism, as revealed by nanosecond time-resolved transient absorption spectroscopy, involves reaction of the excited sensitizer with ascorbic acid to yield [Ru(bpy)<sub>3</sub>]<sup>+</sup> as a primary photogenerated reductant, capable of electron transfer to the cobalt catalyst(s). Under the experimental conditions used, partial decomposition of both the sensitizer and the catalyst is the main deactivation channel for photocatalysis. Optimization of reaction conditions indicated that the use of more reducing iridium or copper-based photosensitizers had a beneficial effect on the catalytic performance. The effect of the different ligands on the catalytic activities of the corresponding cobalt complexes have been investigated by DFT calculations.

Chemistry - A European JournalVol. 31(28)
Institució Catalana de Recerca i Estudis Avançats (ES), Helmholtz Institute Jena (DE), Lund University (SE), Leibniz Institute of Photonic Technology (DE), Institut Català d'Investigació Química (ES), University College London (GB), Friedrich Schiller University Jena (DE), University of Twente (NL), University of Jyväskylä (FI)
Deutsche Forschungsgemeinschaft, National Science Council, Vetenskapsrådet, China Scholarship Council, Sten K Johnsons stiftelse
Clean water and sanitation
Openalex Percentile: Top 46%
Metalloenzymes and iron-sulfur proteins
0.36
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