Visible light-promoted nickel-NHC photocatalysts for free radical photopolymerization and 3D printing application

Autor(es)

Pesqueira, Naralyne M. ; Morlet-Savary, Fabrice ; Schmitt, Michael ; Carvalho Jr, Valdemiro P. ; Goi, Beatriz E. ; Lalevee, Jacques

• Tipo de documento: Artigo Científico
• Fonte: Polymer Chemistry; v. 16, n. 20, p. 13-pg., 2025-04-23.

Resumo

The evaluation of NiII complexes bearing bidentate N-heterocyclic carbene (NHC) ligands has shown their great potential as catalysts in various reactions. However, their luminescence properties and photocatalytic applications remain underexplored. Two novel nickel-based NHC complexes, [Ni(py-NHC)2](PF6)2 (NiC1) and [Ni(ph-NHC)2] (NiC2), were synthesized with ligands N-mesityl-N '-2-pyridylimidazolium tetrafluorophosphate and 1-mesityl-3-phenyl-1H-imidazol-3-ium tetrafluorophosphate, respectively. The complexes were thoroughly characterized using spectroscopy techniques, including FTIR, UV-Vis, 1H NMR, and fluorescence, along with elemental analysis, cyclic voltammetry, and mass spectrometry. NiC1 and NiC2 exhibited emission properties and lifetimes of 3.8 and 9.1 ns, respectively. The photocatalytic properties of NiC1 and NiC2 were investigated for initiating free radical photopolymerization of ethoxylated trimethylolpropane triacrylate under violet light. This process incorporated di-tert-butyl-diphenyl iodonium hexafluorophosphate and ethyl dimethylaminobenzoate as additives. NiC2 achieved the highest monomer conversion under air or in laminate and was effective in on-off LED irradiation. Proposed oxidative and reductive mechanisms were supported by photolysis, fluorescence quenching, and electron spin resonance data. The optimized system was applied in 3D printing, producing smooth-surfaced, high-resolution patterns. (AU)

• Processo FAPESP: 21/13128-1 - Desenvolvimento de novos materiais poliméricos via acoplamento de reações mecanisticamente incompatíveis usando catalisadores heterobimetálicos de Ru/Pd e Ru/Ni
• Beneficiário: Valdemiro Pereira de Carvalho Júnior
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 21/11741-8 - Desenvolvimento de novos complexos de Ni(II) para reações de fotopolimerização radicalar controlada (foto-OMRP e CRP2) e aplicação em impressão 3D
• Beneficiário: Naralyne Martins Pesqueira
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 22/16213-2 - Fotopolimerização radicalar controlada (CRP2) e aplicação em impressão 3D usando novos complexos de Ni(II)
• Beneficiário: Naralyne Martins Pesqueira
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado Direto
• Processo FAPESP: 21/11873-1 - Complexos organometálicos de Mn(II), Fe(II) e Ni(II) como fotocatalisadores redox da CRP2: nova estratégia para fotopolimerização com LEDs
• Beneficiário: Beatriz Eleutério Goi Carvalho
• Modalidade de apoio: Auxílio à Pesquisa - Regular