Remarkable Electronic Effect on the meso-Tetra(thienyl)porphyrins

Autor(es):Mostrar menos -

Leite, Taise H. O. ^[1] ; Grawe, Gregory ^[1] ; Honorato, Joao ^[1] ; Cunha, Beatriz N. ^{[1, 2]} ; Nascimento, Otaciro R. ^[3] ; de Vargas, Pamela S. ^[1] ; Donatoni, Carolina ^[1] ; Oliyeira, Kleber T. ^[1] ; Lopes, Jefferson M. S. ^[4] ; Barbosa Neto, Newton M. ^[4] ; Moreira, Wania C. ^[1] ; Dinelli, Luis R. ^[5] ; Batista, Alzir A. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Dept Quim, CP 676, BR-13565905 Sao Carlos, SP - Brazil

^[2] Inst Fed Goiano, Campus Ceres, Rodovia GO-154 KM 03, CP 51, BR-76300000 Ceres, Go - Brazil

^[3] Univ Sao Paulo, Inst Fis Sao Carlos, CP 369, BR-13560970 Sao Carlos, SP - Brazil

^[4] Univ Fed Para, Inst Ciencias Exatas & Nat, Programa Posgrad Fis, BR-66075110 Belem, Para - Brazil

^[5] Univ Fed Uberlandia, Fac Ciencias Integradas Pontal, Rua Vinte 1600, BR-38304402 Ituiutaba, MG - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Inorganic Chemistry; v. 58, n. 2, p. 1030-1039, JAN 21 2019.
• Citações Web of Science: 2

Resumo

Complexes derived from meso-tetra(thienyl)-porphyrins (TThP) and meso-tetra(pyridyl)porphyrin (TPyP) containing peripheral ruthenium complexes with general formulas [TPyP{[}RuCl(dppb)(5,5'-Mebipy)](4)](PF6)(4), [TThP{[}RuCl-(dppb)(5,5'-Mebipy)](4])(PF6)(4), and [TThP-me-{[}RuCl(dppb)(5,5'-Mebipy)](4)](PF6)(4) {[}5,5'-Mebipy = 5,5'-dimethyl-2,2'-bipyridine and dppb = 1,4-bis(diphenylphosphino)butane] were synthesized and characterized by spectroscopy techniques CH and P-31[H-1]-NMR, IR, UV/vis, fluorescence, and electron paramagnetic resonance (EPR)), cyclic voltammetry, coulometry, molar conductivity, and elemental analysis. Voltammetry and UV/vis studies demonstrated differentiated electronic properties for ruthenium appended with TThP and TThP-me when compared to ruthenium appended with TPyP. The UV/vis analysis for the ruthenium complex derived from TThP and TThP-me, as well as the Soret and Qbands, characteristics of porphyrins, showed a band at 700 nm referring to the Ru -> S electronic transition, and porphyrin TThP-me showed another band at 475 nm from the Ru N transition. The attribution of these bands was confirmed by spectroelectrochemical analysis. Cyclic voltammetry analysis for the ruthenium complex derived from TPyP exhibited only an electrochemical process with E-1/2 = 0.47 V assigned to the Ru(II)/Ru(III) redox pair (Fc/Fc(+)). On the other hand, two processes were observed for the ruthenium complexes derived from TThP and TThP-me, with E1/2 around 0.17 and 0.47 V, which were attributed to the formation of a mixed valence tetranuclear species containing Ru(II) and Ru(III) ions, showing that the peripheral groups are not oxidized at the same potential. Fluorescence spectroscopic experiments show the existence of a mixed state of emission in the supramolecular porphyrin moieties. The results suggest the formation of Ru(II) Ru(III) mixed valence complexes when oxidation potential was applied around 0.17 V in the [TThP{[}RuCl(dppb)(5,5'-Mebipy)](4)](PF6)(4) and [TThP-me{[}RuCl(dppb)(5,5'-Mebipy)](4)](PF6)(4) species. (AU)

• Processo FAPESP: 15/21110-4 - Explorando reações fotocatalisadas em condições de fluxo contínuo pelo uso de sistemas porfirinóides: (C-FlowPhotoChem)
• Beneficiário: Kleber Thiago de Oliveira
• Linha de fomento: Auxílio à Pesquisa - Regular
• Processo FAPESP: 18/00106-7 - Reações fotocatalisadas por porfirinas em condições de fluxo contínuo: arilação de sistemas heterocíclicos e de olefinas ativadas
• Beneficiário: Kleber Thiago de Oliveira
• Linha de fomento: Auxílio à Pesquisa - Regular
• Processo FAPESP: 16/16312-0 - Citotoxidade e mecanismo de ação de complexos de rutênio contendo produtos naturais ou derivados
• Beneficiário: Alzir Azevedo Batista
• Linha de fomento: Auxílio à Pesquisa - Regular