Photo-physical properties of coumarin dyes in isotropic and anisotropic solvents

The absorption and fluorescence spectra of a highly fluorescence laser dye, coumarin (C500, C440, C460), were investigated in isotropic liquids and in nematic solvents as a function of the solvent polarity and type. The interaction of the dye with the anisotropic surrounding and with that of the isotropic solvents was investigated and compared using optical spectroscopy. The spectral behavior of a coumarins was also investigated in anisotropic and isotropic environment for comparison. The spectral shifts were correlated by the solvent polarity and nature.