2026-06-19T17:02:55Zhttps://riubu.ubu.es/oai/request

oai:riubu.ubu.es:10259/68172022-08-26T00:05:14Zcom_10259_4363com_10259_5086com_10259_2604com_10259_4354col_10259_4364col_10259_4355

00925njm 22002777a 4500 dc Cuéllar, Elena author Pastor, Laura author García Herbosa, Gabriel author Nganga, John author Angeles-Boza, Alfredo M. author Diez Varga, Alberto author Torroba Pérez, Tomás author Martín-Alvarez, Jose M. author Miguel, Daniel author Villafañe, Fernando author 2020-12 New cis-(1,2-azole)-aquo bis(2,2′-bipyridyl)ruthenium(II) (1,2-azole (az*H) = pzH (pyrazole), dmpzH (3,5-dimethylpyrazole), and indzH (indazole)) complexes are synthesized via chlorido abstraction from cis-[Ru(bipy)2Cl(az*H)]OTf. The latter are obtained from cis-[Ru(bipy)2Cl2] after the subsequent coordination of the 1,2-azole. All the compounds are characterized by 1H, 13C, 15N NMR spectroscopy as well as IR spectroscopy. Two chlorido complexes (pzH and indzH) and two aquo complexes (indzH and dmpzH) are also characterized by X-ray diffraction. Photophysical and electrochemical studies were carried out on all the complexes. The photophysical data support the phosphorescence of the complexes. The electrochemical behavior of all the complexes in an Ar atmosphere indicate that the oxidation processes assigned to Ru(II) → Ru(III) occurs at higher potentials in the aquo complexes. The reduction processes under Ar lead to several waves, indicating that the complexes undergo successive electron-transfer reductions that are centered in the bipy ligands. The first electron reduction is reversible. The electrochemical behavior in CO2 media is consistent with CO2 electrocatalyzed reduction, where the values of the catalytic activity [icat(CO2)/ip(Ar)] ranged from 2.9 to 10.8. Controlled potential electrolysis of the chlorido and aquo complexes affords CO and formic acid, with the latter as the major product after 2 h. Photocatalytic experiments in MeCN with [Ru(bipy)3]Cl2 as the photosensitizer and TEOA as the electron donor, which were irradiated with >300 nm light for 24 h, led to CO and HCOOH as the main reduction products, achieving a combined turnover number (TONCO+HCOO–) as high as 107 for 2c after 24 h of irradiation. 0020-1669 http://hdl.handle.net/10259/6817 10.1021/acs.inorgchem.0c02716 1520-510X Catalytic reactions Electrochemical reduction Ligands Oxidation Redox reactions (1,2-Azole)bis(bipyridyl)ruthenium(II) Complexes: Electrochemistry, Luminescent Properties, And Electro- And Photocatalysts for CO2 Reduction