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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Cyclic amines homobimetallic ruthenium pre-catalysts bearing bidentate phosphine and their dual catalytic activity for the ring-opening metathesis and atom-radical polymerizations

Texto completo
Autor(es):
Gois, Patrik D. S. [1] ; Cruz, Thais R. [1] ; Martins, Daniele M. [2] ; Machado, Antonio E. H. [3, 4] ; Bogado, Andre L. [5] ; Lima-Neto, Benedito S. [2] ; Goi, Beatriz E. [1] ; Carvalho Jr, Valdemiro P.
Número total de Autores: 8
Afiliação do(s) autor(es):
[1] Univ Estadual Paulista, UNESP, Fac Ciencias & Tecnol, BR-19060900 Presidente Prudente, SP - Brazil
[2] Univ Sao Paulo, Inst Quim Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil
[3] Univ Fed Uberlandia, Inst Quim, POB 593, BR-38400089 Uberlandia, MG - Brazil
[4] Univ Fed Goias, Programa Posgrad Ciencia & Tecnol, Catalao, Go - Brazil
[5] Univ Fed Uberlandia, Inst Ciencias Exatas & Nat Pontal, Rua Vinte 1600, BR-38304402 Ituiutaba, MG - Brazil
Número total de Afiliações: 5
Tipo de documento: Artigo Científico
Fonte: Journal of Molecular Structure; v. 1198, DEC 15 2019.
Citações Web of Science: 0
Resumo

A series of {[}RuCl(dppb)(mu-Cl)(3)Ru(dppb)(amine)] complexes, where amine is pyrrolidine (1), piperidine (2) or perhydroazepine (3), were synthesized and characterized by elemental analysis, FTIR, UV-Vis, and H-1, C-13[H-1] and P-31[H-1] NMR spectroscopy. The electrochemistry properties of the complexes 1-3 were investigated by cyclic voltammetry and exhibited two successive single-electron oxidation processes. The presence of two redox pairs suggests the formation of a dimeric species in which two different fragments, [Ru(amine)(dppb)] and [RuCl(dppb)], were connected via three mu-chloro bridges. The complexes 1-3 were evaluated as catalytic precursors for ROMP of norbornene (NBE) and norbornadiene (NBD), as well as for ATRP of methyl methacrylate (MMA). The polynorbornene (polyNBE) syntheses via ROMP using the complexes 1-3 as pre-catalysts were assessed under reaction conditions of {[}EDA]/{[}Ru] = 28 (5 mu L) and {[}NBE]/{[}Ru] = 5000 as a function of time at 25 or 50 degrees C. Polymerization of MMA via ATRP was conducted using the complexes 1-3 in the presence of ethyl 2-bromoisobutyrate (EBiB) as initiator. Differences in the catalytic activities and polymerization controls were observed in the order 3 > 2 > 1 for both reactions. The activities were discussed considering the steric hindrance and electronic characteristics of the amines as ancillary ligands in the metal center using cyclic voltammetry and NMR studies. (C) 2019 Elsevier B.V. All rights reserved. (AU)

Processo FAPESP: 18/06340-1 - Complexos bimetálicos de rutênio(II) e níquel(II): acoplamento de reações mecanisticamente incompatíveis usando catalisadores multifuncionais via catálise tandem
Beneficiário:Valdemiro Pereira de Carvalho Júnior
Linha de fomento: Auxílio à Pesquisa - Regular
Processo FAPESP: 17/06329-5 - Desenvolvimento de complexos de rutênio com aminas como ligantes ancilares para catálise homogênea de reações de polimerização de olefinas cíclicas via metátese
Beneficiário:Benedito dos Santos Lima Neto
Linha de fomento: Auxílio à Pesquisa - Regular