Design, synthesis, crystal structure and photophysical studies of an emissive, terbium based sensor for zinc

The synthesis, crystal structure and photophysical studies of the probe complex Tb · L are described. Tb · L is a mononuclear complex with a 46-membered macrocyclic rings constructed by intermolecular hydrogen bond. The mononuclear complex Tb · L shows Laporte-forbidden 5D4 → 7FJ f–f transitions and exhibits strong green luminescence emission bands in the solid state at ambient temperature which is characteristic of terbium ion. New selective luminescent lanthanide chemosensor for Zn(II) ion based on Tb · L is also described, suggesting host–guest complexation signaling transduction mechanism.

Graphical abstractA new selective lanthanide luminescent sensor for Zn(II) as well as its supramolecular structure is described here. The participation of nitrogen atoms in binding with Zn(II) complexation helps in the release of fluorescence through efficient intramolecular energy transfer from the pyridyl group to the Tb(III) ion. Thus Tb · L represents a new case of luminescence enhancement with Zn(II) ion. This finding may not only enlarge the arsenal for detecting Zn(II) ion, but also add new merits to the chemistry of salicylamide derivatives, which are usually used as the chromophore for the lanthanide luminescence and constituents for tunable supramolecular chemistry.Figure optionsDownload full-size imageDownload as PowerPoint slide