| Texto completo | |
| Autor(es): |
Cruz, Thais R.
;
Silva, Eliada A.
;
Oliveira, Douglas P.
;
Martins, Daniele M.
;
Gois, Patrik D. S.
;
Machado, Antonio E. H.
;
Maia, Pedro Ivo S.
;
Goi, Beatriz E.
;
Lima-Neto, Benedito S.
;
Carvalho-Jr, Valdemiro P.
Número total de Autores: 10
|
| Tipo de documento: | Artigo Científico |
| Fonte: | APPLIED ORGANOMETALLIC CHEMISTRY; v. 34, n. 5, p. 12-pg., 2020-02-20. |
| Resumo | |
Arene ruthenium(II) complexes bearing the cyclic amines RuCl2(eta(6)-p-cymene)(pyrrolidine)] (1), [RuCl2(eta(6)-p-cymene)(piperidine)] (2), and [RuCl2(eta(6)-p-cymene)(peridroazepine)] (3) were successfully synthesized. Complexes 1-3 were fully characterized by means of Fourier transform infrared, UV-visible, and NMR spectroscopy, elemental analysis, cyclic voltammetry, computational methods, and one of the complexes was further studied by single crystal X-ray crystallography. These compounds were evaluated as catalytic precursors for ring-opening metathesis polymerization (ROMP) of norbornene (NBE) and atom-transfer radical polymerization (ATRP) of methyl methacrylate (MMA). NBE polymerization via ROMP was evaluated using complexes 1-3 as precatalysts in the presence of ethyl diazoacetate (EDA) under different [NBE]/[EDA]/[Ru] ratios, temperatures (25 and 50 degrees C), and reaction times (5-60 min). The highest yields of polyNBE were obtained with [NBE]/[EDA]/[Ru] = 5000/28/1 for 60 min at 50 degrees C. MMA polymerization via ATRP was conducted using 1-3 as catalysts in the presence of ethyl-alpha-bromoisobutyrate (EBiB) as initiator. The catalytic tests were evaluated as a function of the reaction time using the initial molar ratio of [MMA]/[EBiB]/[Ru] = 1000/2/1 at 95 degrees C. The increase in molecular weight as function of time indicates that complexes 1-3 were able to mediate the MMA polymerization with an acceptable rate and some level of control. Differences in the rate of polymerization were observed in the order 3 > 2 > 1 for the ROMP and ATRP. (AU) | |
| 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 |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |
| 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 |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |