Investigations on Photophysical Properties of some Coumarin Based Fluorophores

Abstract

The study of the interaction of radiation with organic fluorophores at the molecular levels newline(Photophysical properties) have earned immense significance for many decades [1-3]. The newlinephotophysical properties of organic fluorophores provide crucial information about excited newlineelectronic states, solute-solvent interactions, geometric and electronic structure of organic newlinemolecules in short-lived state and the molecular environment surrounding the newlinemacromolecules. The photophysics of organic fluorophores is an area of increasing interest. newlineA better knowledge of the properties of excited states of fluorophores provides a deeper newlineunderstanding in the formulation of novel compounds for important applications like laser newlinedyes, micellar, biological systems for molecular devices and probes for polymers etc. Some newlineof the important excited state photophysical properties are quantum yield in different newlineenvironments, fluorescence lifetime, fluorescence quenching by excitation energy transfer, newlinefluorescence enhancement, dipole moment and orientation of molecules in the excited state newlineetc. [4, 5]. newlineThe quantum yield and fluorescence lifetime photophysical properties are significant newlinecharacteristics of organic fluorophores. The probability of an excited state being de-excited newlineby fluorescence is given by quantum yield measurements. The lifetime measurement gives newlinethe time available for the organic fluorophore to interact with its environment and provides newlinethe excited state reaction and rate of energy transfer between the molecules. Also, newlinefluorescence quenching is extensively utilized as a probe in many chemical sensors to newlinedetect chemical groups newline