Synthesis and Characterization of Iridium(III) Complexes with Substituted Phenylimidazo(4,5-)1,10-phenanthroline Ancillary Ligands and Their Application in LEC Devices.

In this work, we report on the synthesis and characterization of six new iridium(III) complexes of the type [Ir(C^N)(N^N)] using 2-phenylpyridine (-) and its fluorinated derivative (-) as cyclometalating ligands (C^N) and R-phenylimidazo(4,5-)1,10-phenanthroline (R = H, CH, F) as the ancillary ligand (N^N). These luminescent complexes have been fully characterized through optical and electrochemical studies. In solution, the - series exhibits quantum yields (Ф) twice as high as the - series, exceeding 60% in dichloromethane and where MLCT/LLCT and LC emissions participate in the phenomenon.

A Proton-Coupled Electron Transfer Strategy to the Redox-Neutral Photocatalytic CO Fixation.

Herein, we report our study on the design and development of a novel photocarboxylation method. We have used an organic photoredox catalyst (PC, 4CzIPN) and differently substituted dihydropyridines (DHPs) in combination with an organic base (1,5,7-triazabicyclodec-5-ene, TBD) to access a proton-coupled electron transfer (PCET) based manifold. In depth mechanistic investigations merging experimental analysis (NMR, IR, cyclic voltammetry) and density-functional theory (DFT) calculations reveal the key activity of a H-bonding complex between the DHP and the base.