Accessible ring opening metathesis and atom transfer radical polymerization catalysts based on dimethyl sulfoxide ruthenium(II) complexes bearing N-heterocyclic carbene ligands

Author(s)

Idehara, Andre H. S. ^[1] ; Gois, Patrik D. S. ^[1] ; Fernandez, Henrique ^[2] ; Goi, Beatriz E. ^[1] ; Machado, Antonio E. H. ^[3] ; Lima-Neto, Benedito S. ^[2] ; Carvalho, Jr., Valdemiro P. ^[1]

Affiliation

^[1] UNESP, Univ Estadual Paulista, 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, BR-38400902 Uberlandia, MG - Brazil

• Document type: Journal article
• Source: MOLECULAR CATALYSIS; v. 448, p. 135-143, APR 2018.
• Web of Science Citations: 2

Abstract

Dimethyl sulfoxide ruthenium(11) complexes of N-heterocyclic carbenes derived from cycloalkylamines (cycloallcyl = cyclopentyl (1a), cyclohexyl (1b), cycloheptyl (1c), and cyclooctyl (1d)) were synthesized: {[}RuCl2(S-dmso)(2)(IPent)] (2a), {[}RuCl2(S center dot dmso)(2)(IHex)) (2b), (RuCl2(S-dmso)(2)(IHept)) (2c), and {[}RuCl2(S center dot dmso)(2)(IOct)) (2d). The imidazolium salts 1a-1d were characterized by FTIR, UV-vis, and H-1 and C-13 NMR spectroscopy, while their respective dimethyl sulfoxide ruthenium(II) complexes (2a-2d) were characterized by elemental analysis, FIR, UV-vis, H-1 and C-13 NMR, and cyclic voltammetry. The complexes 2a-2d were evaluated as catalytic precursors for ROMP of norbornene (NBE) and for ATRP of methyl methacrylate (MMA). The polynorbomene (polyNBE) syntheses via ROMP using the complexes 2a-2d as pre-catalysts were evaluated under reaction conditions of {[}EDA]/{[}Ru] = 28 (5 mu L), {[}NBE]/{[}Ru] = 5000 at 50 degrees C as a function of time. The polymerization of MMA via ATRP was conducted using the complexes 2a-2d in the presence of ethyl 2-bromoisobutyrate (EBiB) as the initiator. All tests were using the molar ratio {[}MMA]/{[}EBiB]/{[}Ru] = 1000/2/1 and conducted at 85 degrees C. The linear correlation of In({[}MMA](0)/{[}MMA]) and time clearly indicates that the concentration of radicals remains constant during the polymerization and that the ATRP of MMA mediated by 2a-2d proceeds in a controlled manner. (AU)

• FAPESP's process: 13/10002-0 - Development of ruthenium complexes as dual catalytic systems in simultaneous polymerization ROMP/ATRP
• Grantee: Valdemiro Pereira de Carvalho Júnior
• Support Opportunities: Research Grants - Young Investigators Grants