Ni(II) complexes for controlled radical photopolymerization reactions (photo-OMRP and CRP2) and application in 3D printing

Abstract

Complexes of NiII metal will be synthesized to catalyze/control Controlled Radical Photopolymerization reactions (photo-OMRP and CRP2). The proposal extends into three stages, which are completely interconnected in the development process. Initially, attention will be directed to the synthesis of Schiff base ligands and non-symmetric NHCs and their respective Ni(II) complexes, involving the entire characterization part through the FTIR, UV-Vis, EPR, 1H and 13C NMR techniques, elemental analysis and mass spectrometry. The second stage will be dedicated to the evaluation of the photochemical properties of the complexes synthesized with Schiff base ligands and with NHCs ligands, considering that they will be used as CRP2 photoinitiator systems. The third step will be dedicated to the evaluation of Ni(II) complexes as photo-OMRP mediators and CRP2 redox photocatalysts using vinyl acetate, methyl acrylate, butyl acrylate and methyl methacrylate monomers. In CRP2, the Ni(II) redox photocatalysts will be studied in the presence of phenacyl bromide and EDB amine under LED irradiation. The copolymerization of selected monomers will also be evaluated using the most efficient photoinitiator systems in the photocontrol of homopolymerization and also the application in 3D printing based on stereolithography. It is intended, therefore, to achieve a fine adjustment of the electronic, electrochemical and steric properties in the coordination sphere of the Ni(II) metal complexes through the combination of ancillary ligands, in order to find the ideal reactivity to promote a satisfactory efficiency in this reaction. (AU)