Advanced search
Start date
Betweenand
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Unusual Photooxidation of S-Bonded Mercaptopyridine in a Mixed Ligand Ruthenium(II) Complex with Terpyridine and Bipyridine Ligands

Full text
Author(s):
da Silva, Maria Rosana E. [1, 2] ; Auvray, Thomas [2] ; Laramee-Milette, Baptiste [2] ; Franco, Mauricio P. [1] ; Braga, Ataualpa A. C. [1] ; Toma, Henrique E. [1] ; Hanan, Garry S. [2]
Total Authors: 7
Affiliation:
[1] Univ Sao Paulo, Inst Chem, Av Prof Lineu Prestes 748, BR-05508000 Sao Paulo, SP - Brazil
[2] Univ Montreal, Dept Chim, Montreal, PQ H3T 1J4 - Canada
Total Affiliations: 2
Document type: Journal article
Source: Inorganic Chemistry; v. 57, n. 9, p. 4898-4905, MAY 7 2018.
Web of Science Citations: 4
Abstract

An unusual photooxidation of a coordinated 4-mercaptopyridine (SpyH) ligand in the {[}Ru(Hmctpy)(dmbpy)(kappa S-SpyH)](2+) complex (Hmctpy = 4'-carboxy-2,2';6',2 `'-terpyridine, dmbpy = 4,4'-dimethyl-2,2'-bipyridine) takes place under visible and UV irradiation, in aerated acetonitrile. The {[}Ru(mctpy)(dmbpy)(kappa S-SO(2)py)] sulfinato product has been characterized by a variety of methods, including X-ray diffraction which supports the presence of the Ru-kappa S-SpyH isomer in the starting complex. The photooxidation of the 4-mercaptopyridine ligand enhances the back-bonding interactions in the complex by means of the strongly acceptor 4-pyridinesulfinato-SO(2)py species, increasing the redox potential of the Ru(III)/Ru(II) couple significantly from 1.23 to 1.62 V. It also led to pronounced changes in the electronic and NMR spectra of the complexes, corroborated by DFT and ZINDO-S calculations. A possible mechanism based on referenced data of photooxidation has been proposed, which involves the formation of a reactive oxygen species and intermediate endoperoxide species, yielding a very stable Ru-sulfinato product. This novel species exhibits stronger luminescence (Phi(f) = 0.004) than the starting complex under UV excitation. (AU)

FAPESP's process: 13/24725-4 - Supramolecular chemistry and nanotechnology
Grantee:Henrique Eisi Toma
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 14/25770-6 - New frontiers in cross-coupling reactions promoted by palladium: combining enantioselective catalysis, C-H activations, new materials and in flux reactions aiming at high efficiency and sustainability in synthetic processes
Grantee:Carlos Roque Duarte Correia
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 15/01491-3 - Theoretical study of cross-coupling reactions: homogeneous and heterogeneous catalysis
Grantee:Ataualpa Albert Carmo Braga
Support Opportunities: Regular Research Grants