In situ-generated arene-ruthenium catalysts bearing cycloalkylamines for the ring-opening metathesis polymerization of norbornene
Arene-ruthenium complexes of type [RuCl2(p-cymene)(cyclo-alkylamine)], where alkyl is pentyl (1), hexyl (2), heptyl (3) or octyl (4), were successful synthetized and applied as pre-catalysts in ROMP of norbornene (NBE). From experiments as a function of temperature and NBE loads, the yields increase...
| Autores: | , , , , , , , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2020 |
| País: | Brasil |
| Recursos: | Universidade Estadual Paulista (UNESP) |
| Repositorio: | Repositório Institucional da UNESP |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.unesp.br:11449/205493 |
| Acesso em linha: | http://dx.doi.org/10.1016/j.cattod.2020.10.018 http://hdl.handle.net/11449/205493 |
| Access Level: | acceso abierto |
| Palavra-chave: | Ancillary ligands Cycloalkylamines DFT study mechanism Norbornene ROMP Ruthenium |
| Resumo: | Arene-ruthenium complexes of type [RuCl2(p-cymene)(cyclo-alkylamine)], where alkyl is pentyl (1), hexyl (2), heptyl (3) or octyl (4), were successful synthetized and applied as pre-catalysts in ROMP of norbornene (NBE). From experiments as a function of temperature and NBE loads, the yields increased with increasing cyclo-alkyl ring size (4 > 3 > 2 > 1). This was associated with steric-electronic features of the amine ligands. The highest yields of polyNBE were obtained with [NBE]/[Ru] molar reaction ratio = 5000/1 in the presence of EDA at 50 °C for 60 min, with molecular weight range of 3.6–5.9 × 104 g mol−1 and Ð of 1.6–2.3. Characterization data obtained from CHN elemental analysis, spectroscopic techniques (FTIR, UV–vis, and 1H- and 13C{1H} NMR), cyclic voltammetry, computational studies, and single crystal diffraction for complexes 2 and 4 were useful for understanding the pre-catalyst behavior. Thermodynamic parameters from DFT-calculation corroborate a ROMP process via a dissociative mechanism. |
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