Novel triphenylamine-based star-like molecules 11 were synthesized and characterized using FT-IR, 1 H, 13 C, and DEPT-135 NMR spectroscopy, and MALDI-TOF mass spectrometry. The absorption and emission spectra of star-like molecules were studied in different solvents. The effect of solvent polarity and aggregation studies on the absorption and emission spectra has also been studied. The new starlike molecules are found to exhibit broad absorption and emission band along with intramolecular charge transfer character. The fluorescence spectra of triphenylamine derivatives shift from blue to green wavelength on increasing the extended conjugation of the molecule. The experimental results indicate that there is cooperative enhancement originating from the inter-branch coupling and an increase in the light-harvesting ability upon increasing the conjugated molecule size.

New types of bis-quaternary ammonium bromide as chiral multisite phase transfer catalysts derived from cinchona alkaloids have been developed and evaluated for the enantioselective epoxidation of chalcones in the presence of lower concentrations of various oxidants, bases and ultrasonic irradiation conditions.

We reported the synthesis of a new series of azobiphenyl based urea derivatives 7 and their stimulus-responsive supramolecular structures in the form of sheet like self-assembled formations. The self-assembled nanostructural formations of azo derivatives 7 are strongly dependent on the nature of the solvent present in the systems. Further, we found that the amide hydrogen played a crucial role in hydrogen bonding interactions to form a sheet like morphology upon stimulus responsive self-assembly. This was confirmed by transmission electron microscopy and atomic force microscopy.

New types of mesitylene based tri-site containing asymmetric quaternary ammonium salts 9a and 9b have been prepared and used as efficient chiral phase transfer catalysts for enantioselective Michael addition reactions between the chalcones and diethylmalonate under mild reaction conditions such as lower concentration of base, catalyst and ultrasonic conditions with very good chemical yields (up to 98%) and ee's (up to 99%).