Development of Ni(II) Complexes Based on Thiosemicarbazides as Photocatalysts in Free-Radical Photopolymerization

Resumo

Developing efficient and cost-effective photoinitiating systems that operate under mild conditions remains a key challenge in light-driven polymerization. In particular, the development of systems based on low-cost metal complexes has gained attention as a promising strategy to replace expensive transition metals such as ruthenium or iridium. In this context, monometallic Ni(II) complexes of the type [Ni(N,N,S-tsc)(4-aminopyridine)] (Ni^Me and Ni^Ph), incorporating tridentate ligands derived from thiosemicarbazides, were synthesized. These complexes were characterized using various spectroscopic techniques, and their catalytic activity was evaluated in free-radical photopolymerization (FRP) reactions. This study investigates the role of light in modulating the reactivity of these nickel-based systems, aiming to elucidate their catalytic performance and contribute to the development of new transition-metal photocatalysts for applications in homogeneous catalysis.