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

• Autor(a) principal: Bignardi, Camila [UNESP]
• Data de Publicação: 2022
• Outros Autores: Oliveira, Larissa F. [UNESP], Pesqueira, Naralyne M. [UNESP], Riga-Rocha, Beatriz A. [UNESP], Machado, Antonio E.H., Carvalho-Jr, Valdemiro P. [UNESP], Goi, Beatriz E. [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1016/j.jphotochem.2021.113595; http://hdl.handle.net/11449/222619
• topic: CoII complexes; n-Butyl acrylate; photo-OMRP; Tetradentate Schiff-base

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(2,4,6-trimethylbenzoyl)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 (Ð < 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.