Efficient near-infrared emission of a Ytterbium(III) compound with a green light rhodamine donor

A new approach to design and synthesize efficient near-infrared luminescent ytterbium(III) compound has been achieved through incorporating a ring-opened rhodamine unit as energy donor with the excitation wavelength in the visible range (500 nm). The tetradentate binding unit of ligand fulfils the high coordination numbers of the lanthanide cation ensuring the efficient NIR emission.