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

CoII complexes with non-symmetrical tetradentate Schiff-base ligands were applied in the photo-OMRP of butyl acrylate under 390 nm UV irradiation. [Display omitted] •CoII complexes with non-symmetrical tetradentate Schiff-base ligands were prepared.•Three new CoII complexes were applied in the photo induced OMRP of butyl acrylate.•CoII complexes were able to control the polymerization under 390 nm UV irradiation.•Experimental and theoretical data suggest a majority reversible termination pathway. 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