The right substituent, at the right place : predicting the modulation of UV-visible absorption and emission of mono-substituted pyrido[2,3,4-kl]acridines by electron density variations analysis

DFT and TD-DFT calculations were performed to rationalize the relationship between UV-Visible absorption and emission spectraand the nature and position of a substituent on the heteroaromatic pyrido[2,3,4-kl]acridine skeleton. Studying the variation of electron density and partial charges between the ground state and the first excited state, we describe here a quantitative method to predict the modulation of UV-Visible spectroscopic properties depending on the nature and the position of a substituent.