Photoinduced organometallic mediating radical polymerization of acrylates mediated by CoII complexes of non-symmetrical tetradentate Schiff-base ligands

Autor(es)

Bignardi, Camila ; Oliveira, Larissa F. ; Pesqueira, Naralyne M. ; Riga-Rocha, Beatriz A. ; Machado, Antonio E. H. ; Carvalho-Jr, Valdemiro P. ; Goi, Beatriz E.

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY; v. 423, p. 9-pg., 2021-10-11.

Resumo

Three new cobalt(II) complexes with non-symmetrically-substituted N2O2 tetradentate Schiff-base ligands, prepared from the 1:1:1 condensation of 3-etoxy-salicylaldehyde, salicylaldehyde and ethylenediamine (H2Etsal 1), o-phenylenediamine (H2Phsal - 2) or 1,2-cis,trans-cyclohexyldiamine (H2Cysal - 3), were synthesized. The complexes 1-3 were characterized by UV-Vis, FTIR, and MALDI-TOF spectroscopy, elemental analysis, molar conductance, cyclic voltammetry, and computational methods. The CoII-Schiff-base complexes (1-3) were used as controlling agents for the polymerization of n-butyl acrylate (BA) photoinitiated by diphenyl(2,4,6trimethylbenzoyl)phosphine oxide (TPO), according to an organometallic-mediated radical polymerization (OMRP) mechanism. Although, all complexes have presented good control ability, the polymerization mediated by complex 1 showed the best control over molecular weight (Mn matching with Mn,th) and dispersity ((SIC) < 1.50). Kinetic results and computational investigations support the activation/deactivation equilibrium, exerted by complexes 1-3, occurring by one face of the complexes via reversible termination (RT) mechanism.minim. (AU)

• Processo FAPESP: 18/06340-1 - Complexos bimetálicos de rutênio(II) e níquel(II): acoplamento de reações mecanisticamente incompatíveis usando catalisadores multifuncionais via catálise tandem
• Beneficiário: Valdemiro Pereira de Carvalho Júnior
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 18/19395-9 - Síntese de novos complexos organometálicos de Fe(III), Co(III) e Ni(III) coordenados a bases de Schiff assimétricas para mediar a foto-OMRP
• Beneficiário: Beatriz Eleutério Goi Carvalho
• Modalidade de apoio: Auxílio à Pesquisa - Regular