LAUSR

Abstract A comprehensive spectroscopic, photophysical and electrochemical investigation of N-alkylacridones, their newly synthesised chlorosulfonyl and water-soluble sulfonic acid derivatives has been undertaken in solution at room temperature. The study includes absorption and emission spectra together with quantitative measurements of the deactivation of the first excited singlet state, from which the rate constants for all the decay processes has been obtained. A comparison on the gradual change of the electronic spectral and photophysical properties with the degree of substitution is considered. In addition the electrochemical behavior of the water-soluble acridones at different pH values was obtained by cyclic and differential pulse voltammetry. The oxidation mechanism of disulfonated acridone is found to occur in one consecutive and irreversible charge transfer pH-dependent reaction. The water-soluble acridones were found to display long lifetime values, dependent on the pH and solvent polarity. This opens a door for its use as selective probes for different cellular environment and targets.