Neutral Dinuclear Silver(I)-NHC Complexes: Synthesis and Photophysics

We report the synthesis and characterization of a new anionic pincer-type mu(2)-eta(2)(1 kappa C-carbene:2 kappa C'(carbene))-C*-N-C*) ligand with a triazine core. Hydrolysis of one chloro substituent of the cyanuric chloride leads to the hydroxy-2,4-dichloro-1,3,5-triazine and the corresponding bis(imidazolium) salts, which, after deprotonation, serve as monoanionic ligands. Treatment of the bis(imidazolium) precursor with silver(I) oxide leads to stable silver(I)-NHC complexes with interesting photophysical properties (phosphorescent emission in the deep blue region of the spectrum). Depending on the substitution pattern of the NHC ligand, the emission can be shifted between 417 and 480 nm. X-ray structure analysis reveals the dimeric structure of these complexes.