title: Solvents effect on the absorption and fluorescence spectra of 7-diethylamino-3-thenoylcoumarin: evaluation and correlation between solvatochromism and solvent polarity parameters.
abstract: Effect of solvents of varying polarities on absorption and fluorescence spectra and dipole moment of laser dye: 7-diethylamino-3-thenoylcoumarin (DETC) has been investigated. A small band shift is obtained in the absorption spectra compared to emission spectra. The spectral shifts were correlated with Catalan's parameters using linear solvation energy relationship. It reveals that non-specific interaction measured by solvent polarity has more influence on absorption and solvent dipolarity contribution is significant in case of fluorescence. A bathochromic shift observed in absorption and emission spectra with increasing solvent polarity, which implied that the transition involved is π→π(∗). The solvatochromic correlations were used to estimate the excited state dipole moment using experimentally determined ground state dipole moment. The observed single-state excited state dipole moment is found to be greater than the ground state.
authors.affiliation: Department of Physics, Siddaganga Institute of Technology, Tumkur 572 103, India.
authors.forename: Jana
authors.initials: J
authors.lastname: Basavaraja
authors.affiliation: Laser Spectroscopy Programme, Department of Physics, Karnatak University, Dharwad 580 003, India.
authors.forename: S R
authors.initials: SR
authors.lastname: Inamdar
authors.affiliation: Department of Physics, Siddaganga Institute of Technology, Tumkur 572 103, India. Electronic address: sureshkumarhm@rediffmail.com.
authors.forename: H M
authors.initials: HM
authors.lastname: Suresh Kumar
mesh_terms: D004396:Coloring Agents / Q000737:chemistry*; D003374:Coumarins / Q000737:chemistry*; D012997:Solvents; D013050:Spectrometry, Fluorescence; D013876:Thiophenes / Q000737:chemistry*
chemical_list: D004396:Coloring Agents; D003374:Coumarins; D012997:Solvents; D013876:Thiophenes
keywords: Coumarin; Dipole moment; Intramolecular charge transfer; Preferential solvation; Solvatochromic; Solvent polarity