Cooperative Effects of Aniline with DMSO in Ru-II Complexes: Tuning the Reactivity for Ring-Opening Metathesis Polymerization

Autor(es)

Martins, Daniele M. ^[1] ; Maia, Pedro I. S. ^[2] ; Carvalho-Jr, Valdemiro P. ; Lima-Neto, Benedito S. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Quim Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil

^[2] Univ Fed Triangulo Mineiro, Dept Quim, BR-38025440 Uberaba, MG - Brazil

• Tipo de documento: Artigo Científico
• Fonte: European Journal of Inorganic Chemistry; v. 2019, n. 41, p. 4421-4426, NOV 10 2019.
• Citações Web of Science: 2

Resumo

The complex cis,fac-{[}RuCl2(DMSO-O)(DMSO-S)(3)] {[}1] reacted with aniline (NH2Ph) under reflux to produce the complex trans,cis,cis-{[}RuCl2(DMSO-S)(2)(NH2Ph)(2)] {[}2], whereas at room temperature the resulting complex was cis,fac-{[}RuCl2(DMSO-S)(3)(NH2Ph)] {[}3]. The complexes were characterized by FTIR, EPR, H-1 and C-13 NMR, electronic spectra, and the crystal structure of 2 was determined by single X-ray crystallography. The influence of NH2Ph and DMSO as ancillary ligands in the new complexes was then evaluated for ring-opening metathesis polymerization (ROMP) of norbornene (NBE), norbornadiene (NBD), and dicyclopentadiene (DCPD) in presence of ethyl diazoacetate (EDA) with different {[}monomer]/{[}Ru] molar ratios. Homopolymers of NBE with molecular weights in the order of magnitude of 10(5) g.mol(-1) and insoluble polymers in CHCl3 from NBD and DCPD were obtained in different yields depending of the starting complex, reaction time (5 and 30 min), and temperature (25 and 50 degrees C). Valorous results were obtained for polyNBD, polyDCPD, and copolymerizations from NBE with NBD or DCPD using the new complexes, affording higher yields than with 1. In conclusion, beneficial effects are observed when DMSO and the weak sigma-donor NH2Ph ligands are arranged in the same coordination sphere of Ru(II) pre-catalysts for ROMP. (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
• Modalidade de apoio: 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
• Modalidade de apoio: Auxílio à Pesquisa - Regular