Synthesis and application of ruthenium complexes bearing Bi-Phosphines and N-heterocyclic carbenes as dual catalysts in mechanistically-incompatible reactions (ROMP and ATRP)

• Grant number: 19/07252-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2019
• End date: July 31, 2020
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Valdemiro Pereira de Carvalho Júnior
• Grantee: Douglas Henrique Nunes Santos
• Host Institution: Faculdade de Ciências e Tecnologia (FCT). Universidade Estadual Paulista (UNESP). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil

Abstract

Ruthenium complexes will be synthesized to catalyze cyclic olefin polymerization reactions via ROMP (ring-opening metathesis polymerization) and atom transfer radical polymerization (ATRP) radical polymerization. The proposal is to systematically evaluate different combinations of ancillary binders in the sphere of coordination of the complexes and, consequently, to achieve a fine adjustment through the variation of the electronic and steric contributions in the metallic center, directing the reactivity of these complexes to act efficiently in the tandem ROMP / ATRP catalysis. The binders evaluated will be different carbenes and bisphosphonates coordinated simultaneously to the center of ruthenium against the polymerization of cyclic monomers unsaturated via ROMP and the polymerization of vinyl monomers via ATRP to obtain block copolymers. Initially, the research will focus on the catalytic activity of the complexes in the ROMP and the ATRP separately, considering that a thorough understanding of the individual reactions is a key step in the development of dual catalysts for tandem ROMP / ATRP catalysis. It is intended, therefore, to establish fundamentals for the understanding of the performance of the catalysts, as well as the formation of the reaction intermediates involved in each reaction and, thus, enable the planning of dual catalytic systems combining reactivity and selectivity for the synthesis of new materials with differentiated architecture via tandem polymerization ROMP / ATRP.