Photophysical properties and estimation of ground and excited state dipole moments of Rhodomine-123 laser dye

Article English OPEN
Pattanashetti, Dr. I I ; Meti, Prabhu M ; Rayar, Jyoti N (2014)
  • Publisher: Journal of Engineering Computers & Applied Sciences
  • Journal: Journal of Engineering Computers & Applied Sciences (issn: 2319-5606, eissn: 2319-5606)
  • Subject: Engineering; Department of Physics
    arxiv: Physics::Chemical Physics

The present paper reports about the study of Stokes shift for the Rhodomine-123 molecule in different alcoholic solvents. The ground state dipole moment (g) and the excited state dipole moment (e) of Rhodomine-123 are estimated in various alcoholic solvents by Backshieve [9, 10] and Lippert [8] Kawski-Chamma-Viallet [11, 12], McRae, Suppan [14] equations respectively. Using the variation of stokes shift with the solvent dielectric constant and refractive index with an assumption that the dipole moments of the molecule in ground and excited states were parallel to each other. But after calculation observed that they are oriented with some angle (?). The oscillating strength of molecule and Einstein coefficients have been examined in various solvents. The observation shows that the dipole moment values of excited state (e) were higher than corresponding ground state values (g), indicating a substantial redistribution of the ? electron densities in a more polar excited state than the ground state. From the calculation it is concluded that Kawski-Chamma-Viallet and McRae method is most suitable for the determination of excited state dipole moment, which are in close agreement.
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