Phosphites in combination with p-cymene in ruthenium complexes for catalysis of cyclic olefin polymerizations via metathesis.

• Grant number: 23/09286-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2023
• End date: September 30, 2024
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Analytical Chemistry
• Principal Investigator: Benedito dos Santos Lima Neto
• Grantee: Gabriel Pasian Ferreira Santos
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

This project is part of the research carried out in our Group whose objective is the synthesis of ruthenium complexes for ring-opening metathesis polymerization (ROMP) of cyclic olefins. The present study aims to investigate the electronic behavior of P(OR)3, where R = phenyl (Ph), ethyl (Et), n-butyl (nBu) and i-Propyl (iPr) as ancillary ligands in the sphere of coordination of ruthenium(II) complexes, obtained from the dimer [RuCl2(p-cymeno)]2. The complexes will be synthesized and characterized by elemental analysis (CHN), infrared, mass spectrometry, UV-Vis spectrophotometry, NMR (1H; 13C; 31P) and cyclic voltammetry. The ROMP reactions of norbornene (NBE) and norbornadiene (NBD) and copolymerizations between NBE and NBD will be carried out in the presence of ethyldiazoacetate (EDA) as a function of time (5 - 60 minutes) and temperature (20 - 60 °C). Reaction yields and characteristics of the isolated polymers will be discussed in terms of molecular weights and stereochemistry, correlating the reactivities of the complexes with similar complexes with phosphines. The individual properties in each complex will allow comparisons in the results of the characterizations and reactivity, allowing the electronic and stereo arguments to be directly experienced in each case.