Goutam Masanta

Triphenylamine-Based Receptors in Selective Recognition of Dicarboxylic Acids

New triphenylamine-based chemosensors for selective recognition of dicarboxylic acids have been designed and synthesized. They are variants of previously synthesized chemosensors, offering different possibilities for selective recognition of dicarboxylic acids. Theoretical calculations by density functional theory and time dependent density functional theory have been carried out on these as well as on one of the previously reported systems and on complexes formed by the triphenylamine based chemosensors and aliphatic dicarboxylic acids of different chain-lengths. Carboxylic acid binding takes place through charge-neutral pyridyl amide receptor sites with concomitant quenching of fluorescence of the triphenylamine moiety. The theoretical results are consistent with the experimental and correlation is found between the calculated binding energies and the experimental binding constants.

Anthracene-appended Pyridine Amide: A Simple Sensor for Monocarboxylic Acids

Anthracene-appended receptor 1, which can function as an “on–off” fluorescence switch for monocarboxylic acids, has been designed and synthesized. The photophysical behavior of 1 has been examined by fluorescence, UV–vis and NMR spectroscopy.

Anthracene-based open and macrocyclic receptors in the flurometric detection of urea

Anthracene-based open and macrocyclic receptors 1 and 2 have been designed and synthesized for the recognition of urea in less polar CHCl3 and more polar CH3CN solvents. Receptor 1 binds urea strongly in CHCl3 and exhibits a significant increase in the emission of the anthracene. Macrocyclic analogue 2 shows higher binding and good sensibility towards urea due to the macrocyclic effect. In CH3CN, the binding constant values are lower in magnitude, but the trend is similar to that seen in CHCl3. Both the receptors 1 and 2 are examples of PET sensors for the recognition of urea.