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.)

Effects of a strong pi-accepting ancillary ligand on the water oxidation activity of weakly coupled binuclear ruthenium catalysts

Full text
Author(s):
Matias, Tiago A. [1] ; Rein, Francisca N. [2] ; Rocha, Reginaldo C. [2] ; Barboza Formiga, Andre Luiz [3] ; Toma, Henrique E. [1] ; Araki, Koiti [1]
Total Authors: 6
Affiliation:
[1] Univ Sao Paulo, Inst Chem, Dept Chem, Av Lineu Prestes 748, BR-05508000 Sao Paulo, SP - Brazil
[2] Los Alamos Natl Lab, Los Alamos, NM 87545 - USA
[3] Univ Estadual Campinas, UNICAMP, Inst Chem, POB 6154, BR-13083970 Campinas, SP - Brazil
Total Affiliations: 3
Document type: Journal article
Source: DALTON TRANSACTIONS; v. 48, n. 9, p. 3009-3017, MAR 7 2019.
Web of Science Citations: 0
Abstract

Significant differences were found in the proton-coupled redox chemistry and catalytic behavior of the binuclear {[}[Ru(H2O)(bpz)](2)(tpy(2)ph)](PF6)(4) complex {[}bpz = 2,2-bipyrazine; tpy(2)ph = 1,3-bis(4-2,2:6,2-terpyridin-4-yl)benzene] as compared with the structurally analogous derivative with 2,2-bipyridine (bpy) instead of bpz. The differences were assigned to the stronger -accepting character of bpz relative to bpy as the ancillary ligand. The expectation of a positive shift for the Ru-centered redox potentials was confirmed for the lower oxidation state species, but that trend was reversed in the formation of the high-valence catalytic active species as shown by a negative shift of 0.14 V for the potential of the {[}Ru-IV/V?O] process. Moreover, DFT calculations indicated a significant decrease of about 15% on the spin density and oxyl character of the {[}Ru-V?O](3+) fragment. The significantly lower k(cat)(O-2) for the bpz system was attributed to these combined electronic effects. (AU)

FAPESP's process: 14/50906-9 - INCT 2014: in Functional Complex Materials
Grantee:Fernando Galembeck
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 18/03576-4 - Mechanistic studies in water oxidation catalysis promoted by ruthenium complexes bearing imidazole units
Grantee:André Luiz Barboza Formiga
Support Opportunities: Scholarships abroad - Research