The first Cd–Hg 2,2′-bipyridine material: structure, properties and TDDFT calculations

The first Cd-Hg 2,2′-bipyridine compound, [Cd(2,2′-bipy)3](Hg2Cl7)·H3O (1), (2,2′-bipy = 2,2′-bipyridine), has been solvothermally prepared and characterized by single-crystal X-ray diffraction. Compound 1 is characterized by an isolated structure, comprising [Cd(2,2′-bipy)3]2+ cations, (Hg2Cl7)3– anions and protontated lattice water molecules. Photoluminescence investigation discovers that compound 1 displays an emission in the yellow region. It has remarkable CIE (Commission Internationale de I'Éclairage) chromaticity coordinates of (0.5126, 0.4865). Its CCT (Correlated Color Temperature) is 2510 K. Time-dependent density functional theory (TDDFT) calculations reveal that the emission is attributed to ligand-to-ligand charge transfer (LLCT).