In:
Dalton Transactions, Royal Society of Chemistry (RSC), Vol. 52, No. 14 ( 2023), p. 4442-4455
Abstract:
The electrocatalytic properties of Ru complexes are of great technological interest given their potential application in reactions such water splitting and CO 2 reduction. In this work, a novel terpyridine-based Ru( ii ) complex, [RuCl(trpy)(acpy)], trpy = 2,2′:6′,2′′-terpyridine, acpy − = 2-pyridylacetate was synthesized and its spectroscopic, electrochemical and catalytic properties were explored in detail. In dry acetonitrile, the complex exhibits two reduction peaks at −1.95 V and −2.20 V vs. Fc/Fc + , attributed to consecutive 1 e − reduction. Under CO 2 atmosphere, a catalytic wave is observed ( E onset = 2.1 V vs. Fc/Fc + ), with CO as the main reduction product. Bulk electrolysis reveals a turnover number (TON) of 12 ( k obs = 1.5 s −1 ). In the presence of 1% water, an improvement in the catalytic activity is observed (TON CO = 21 and k obs = 2.0 s −1 ) and, additionally, formate was also detected (TON HCOO = 7). Spectroelectrochemical experiments allowed the identification of a metallocarboxylate (Ru–COO − ) intermediate under anhydrous conditions, while in water, the partial labilization of the acpy − ligand was observed in the course of the catalytic cycle. The experimental data was combined with DFT calculations, allowing the proposal of a catalytic cycle. The results establish important relationships between selectivity, ligand structure and reaction conditions.
Type of Medium:
Online Resource
ISSN:
1477-9226
,
1477-9234
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2023
detail.hit.zdb_id:
1472887-4
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