Synthesis and photophysical properties of triphenylamine-based multiply conjugated star-like molecules

Abstract

Novel triphenylamine-based star-like molecules 11 were synthesized and characterized using FT-IR, ¹H, ¹³C, 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 star-like 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.