UV-visile absorption and fluorescence characteristics of the luminescent label coumarin-6-sulphonyl chloride in homogeneous and micellar solutions

This paper describes the study of the UV-visual absorption, Fluorescence emission, and fluorescence excitation spectra of coumarin-6-sulphonyl chloride (C-6SCl) in various organic solvents and buffer solutions. In addition, the spectral behaviour in aqueous micellar systems of anionic and cationic surfactant was investigated. The spectral properties of the compound together with the detemined p_K values in the ground and excited state are discussed in relation to its electronic structure. The results reflect the importance of the medium effect on the analytical application of C-6SCl as a potential luminescent label for derivatization of amino and phenolic groups.