Polynuclear heteroleptic ruthenium(II) photoredox catalysts: Evaluation in blue-light-mediated, regioselective thiol-ene reactions
作者:Nozuko M. Motimani、Siyabonga Ngubane、Gregory S. Smith
DOI:10.1016/j.poly.2021.115616
日期:2022.1
spectra (614–633 nm) relative to the canonical [Ru(bpy)3](PF6)2 complex (609 nm), attributed to the transition from the triplet MLCT excited state (3MLCT) to the ground state. The complexes were evaluated as visible-light photoredox catalysts in the radical hydrothiolation reaction of olefins (thiol-ene coupling) to afford thioethers. Control reactions performed in the absence of the photocatalyst resulted
合成了结合亚胺或胺官能化联吡啶配体的多核杂配钌 (II) 光敏剂(通过席夫碱缩合/还原胺化反应),表征并研究了它们在氢硫醇化反应中的光反应性。此外,还进行了配合物的电化学、电子吸收和发射研究。所有配体修饰的杂配配合物都显示出相对于经典 [Ru(bpy) 3 ](PF 6 ) 2 配合物 (609 nm)的红移发射光谱 (614–633 nm),归因于三重态 MLCT 的转变激发态 ( 3MLCT) 到基态。在烯烃的自由基氢硫醇化反应(硫醇-烯偶联)中,该配合物被评估为可见光光氧化还原催化剂,以提供硫醚。在没有光催化剂的情况下进行的对照反应导致产率显着降低 (6%) 或没有产物形成,证明了配合物作为光氧化还原催化剂的作用。使用三核复合物(E red (Ru 2+*/+ ) = +0.300 V vs Ag/Ag +)进行的反应与它们各自的单核同系物相比产率增加,并且大于 [Ru(bpy) 3