Excited state electric dipole moments of two exalite dyes from solvatocromic shift measurements

Abstract

The determination of excited state electric dipole moment through solvatochromic shifts of two Exalite dyes, namely, E-392A, E-398 have been carried out using fluorescence shifts and have been found to be less than those calculated through absorption shifts. It is felt that the one calculated using shifts in emission are more reliable. The results are presented and discussed. A qualitative estimate of the orientation of dipole moments in ground and excited state are also presented and discussed.

Keywords:

• Electric dipole moment
• Solvatochromic shifts
• Onsager cavity radius
• Solvent dielectric medium
• Exalite dyes

Acknowledgements

The authors acknowledge the help and encouragement shown by the Principal, SDM College of Engineering and technology, Dharwad, India and management of SDME Society, Dharwad, India, in carrying out this work. The authors also wish to express their gratitude to Dr D. K. Deshpande, Rtd Professor of Physics, Karnataka University, Dharwad, India for helpful discussions.