Terpyridine-Functionalized Calixarenes: Synthesis, Characterization and Anion Sensing Applications
Lanthanide complexes have been developed and are reported herein. These complexes were derived from a terpyridine-functionalized calixarene ligand, chelated with Tb3+ and Eu3+. Synthesis of these complexes was achieved in two steps from a calixarene derivative: (1) amide coupling of a calixarene bearing carboxylic acid functionalities and (2) metallation with a lanthanide triflate salt. The ligand and its complexes were characterized by NMR (1H and 13C), fluorescence and UV-vis spectroscopy as well as MS. The photophysical properties of these complexes were studied; high molar absorptivity values, modest quantum yields and luminescence lifetimes on the ms timescale were obtained. Anion binding results in a change in the photophysical properties of the complexes. The anion sensing ability of the Tb(III) complex was evaluated via visual detection, UV-vis and fluorescence studies. The sensor was found to be responsive towards a variety of anions, and large binding constants were obtained for the coordination of anions to the sensor.
Edwards, N.Y., Schnable, D.M., Gearba-Dolocan, I.R., and Strubhar, J.L. (2020). Terpyridine-functionalized calixarenes: Synthesis, characterization and anion sensing applications. Molecules, 26(1). https://doi.org/10.3390/molecules26010087