Efficient Ytterbium Near-Infrared Luminophore Based On A Nondeuterated Ligand

A novel molecular ytterbium complex is reported with a new tetradentate ligand based on the 2,2'-bipyridine-6,6'-dicarboxylic acid scaffold. The photophysical properties are investigated, especially with respect to near-infrared luminescence. The ytterbium complex shows a rather high absolute luminescence quantum yield of Phi = 3.0% and a luminescence lifetime of tau(obs) = 72 mu s at room temperature in CD3OD solution.