Synthesis of organocobalt (iii) complexes as clean sources of radicals for cobalt mediated radical polymerization

• Grant number: 13/11883-0
• Support Opportunities: Regular Research Grants
• Start date: February 01, 2014
• End date: July 31, 2016
• Field of knowledge: Physical Sciences and Mathematics - Chemistry
• Principal Investigator: Beatriz Eleutério Goi Carvalho
• Grantee: Beatriz Eleutério Goi Carvalho
• Host Institution: Faculdade de Ciências e Tecnologia (FCT). Universidade Estadual Paulista (UNESP). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil

Abstract

New organocobalt (III) complexes will be synthesized to catalyze/regulate cobalt-mediated radical polymerization. The proposal is to systematically evaluate different combinations of ancillary ligands in the coordination sphere of cobalt complexes and then, reach a fine tuning through the variation of the electronic and steric contributions, which have the task of driving the reactivity of these complexes to operate efficiently in the reaction CMRP. The investigated ligands will be different diimines and alkyl radicals simultaneously coordinated to the cobalt center to polymerize vinyl monomers via CMRP. The research proposal is divided into three steps, which are completely interlinked with one another in a development process. Initially, attention will be addressed to synthesis of organic precursors of free radicals (symmetrical ketones) via photo-cleavage. The second step will approach the development of new organocobalt complexes under mild conditions by addition of photochemically formed carbon-centered radicals onto cobalt (II) complexes. The last step will be dedicated to evaluating the reactivity of synthesized organocobalt (III) complexes in CMRP reactions directed towards the synthesis of new polymeric materials. The purpose is to provide base for understanding the performance of the catalysts, as well as the formation of reaction intermediates involved in each catalysis and then, design catalytic systems that combine reactivity and selectivity for synthesis of new materials with different architecture obtained by CMRP. (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)

SILVA, TALITA T.; SILVA, YAN F.; MACHADO, ANTONIO E. H.; MAIA, PEDRO IVO S.; TASSO, CARLOS R. B.; LIMA-NETO, BENEDITO S.; SILVA SA, JOSE L.; CARVALHO-JR, VALDEMIRO P.; BATISTA, NOUGA C.; GOI, BEATRIZ E.. Cycloalkyl-substituted salicylaldimine-nickel(II) complexes as mediators in controlled radical polymerization of vinyl acetate. Journal of Macromolecular Science Part A-Pure and Applied Chemistry, v. 56, n. 12, p. 1132-1140, DEC 2 2019. (13/11883-0, 13/10002-0)

SILVA, YAN F.; RIGA, BEATRIZ A.; DEFLON, VICTOR M.; SOUZA, JHONATHAN R.; SILVA, LEONARDO H. F.; MACHADO, ANTONIO E. H.; MAIA, PEDRO IVO S.; CARVALHO-JR VALDEMIRO, P.; GOI, BEATRIZ E.. Organometallic-mediated radical polymerization using well-defined Schiff base cobalt(II) complexes. Journal of Coordination Chemistry, v. 71, n. 22, p. 3776-3789, NOV 17 2018. (13/11883-0, 13/10002-0)