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Development of ruthenium complexes with ammines as ancillary ligands for homogeneous catalysis of ring opening metathesis polymerization of cyclic olefins

Grant number: 17/06329-5
Support type:Regular Research Grants
Duration: August 01, 2017 - January 31, 2020
Field of knowledge:Physical Sciences and Mathematics - Chemistry
Principal Investigator:Benedito dos Santos Lima Neto
Grantee:Benedito dos Santos Lima Neto
Home Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

Ruthenium complexes with cyclic and acyclic amines will be developed to act as catalysts in reactions of ring-opening metathesis polymerization (ROMP). In addition to the ammines in the metal coordination sphere, phosphines, phosphites or sulfoxides will also be present as ancillary ligands. The strategy is to make electronic and steric hindrance combinations by using different ancillary ligands in the coordination sphere of the complex. In this way, the reactivity of the metal center can be controlled regarding the induction period for the formation of the active metal-carbene species, and especially with respect to the initiation and propagation rates in the polymerizations. The resulting complexes may present different affinities for the monomers, affecting the physico-chemical characteristics of the polymers, such as molar mass, polydispersity, degree of crosslinking, solubility, microstructure, thermal and mechanical properties, etc. A variety of unsaturated bicyclic monomers will be tested, e.g., norbornene and derivatives, 7-oxanorbornene and derivatives, norbornadiene, and dicyclopentadiene to obtain homopolymers and copolymers. The derivative parts inserted into the monomers are amides functionalized with fatty acids or N-heterocyclics and esters of fatty acids, all developed throughout the research. The research focuses on aspects of ROMP by considering individual reactions that are key steps in the catalytic cycle or that initiate it. It is intended to provide fundamentals for understanding the performance of pre-catalysts (initiators), and subsequently design chemical systems that combine catalytic activity and polymer syntheses with desirable characteristics, aiming at technology transfer. There is concern with the development of robust complexes that are resistant to storage and reactive in ambient atmosphere. (AU)

Scientific publications
(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)
GOIS, PATRIK D. S.; CRUZ, THAIS R.; MARTINS, DANIELE M.; MACHADO, ANTONIO E. H.; BOGADO, ANDRE L.; LIMA-NETO, BENEDITO S.; GOI, BEATRIZ E.; CARVALHO JR, VALDEMIRO P. Cyclic amines homobimetallic ruthenium pre-catalysts bearing bidentate phosphine and their dual catalytic activity for the ring-opening metathesis and atom-radical polymerizations. Journal of Molecular Structure, v. 1198, DEC 15 2019. Web of Science Citations: 0.
MARTINS, DANIELE M.; MAIA, PEDRO I. S.; CARVALHO-JR, VALDEMIRO P.; LIMA-NETO, BENEDITO S. Cooperative Effects of Aniline with DMSO in Ru-II Complexes: Tuning the Reactivity for Ring-Opening Metathesis Polymerization. European Journal of Inorganic Chemistry, v. 2019, n. 41, p. 4421-4426, NOV 10 2019. Web of Science Citations: 0.
FERREIRA, MARCELLA S.; FERNANDES, HENRIQUE; SILVA SA, JOSE L.; CARVALHO, JR., VALDEMIRO P.; LIMA-NETO, BENEDITO S. ROMP-based biorenewable polymers of norbornene modified with triglycerides or esters from natural buriti oil. POLYMER BULLETIN, v. 76, n. 10, p. 5399-5413, OCT 2019. Web of Science Citations: 0.

Please report errors in scientific publications list by writing to: cdi@fapesp.br.