Dedicated to Professor Józef Heldt on the occasion of his 75th birthday
Keywords:Ethyl 5-(4-dimethylaminophenyl)-3-amino-2,4-dicyanobenzoate Charge transfer fluorescence Donor-acceptor system a b s t r a c tWe report the synthesis and photophysical properties of ethyl 5-(4-dimethylaminophenyl)-3-amino-2,4-dicyanobenzoate (EDMAADCy) in neat solvents of different polarity. The relation between molecular conformations of molecule under study and spectral behavior has been studied using steady-state spectroscopic technique, electrochemical measurements, and quantum-chemical calculations. The fluorescence spectra of EDMAADCy possess, in medium polar solvents, two bands. Theoretical studies of the TICT phenomenon have been made in order to explain the dual emission of the molecule under study. Calculated electric dipole moments in the ground and excited states, for perpendicular and flatted conformers, have been compared with experimentally determined data. Additionally, the results of spectroscopic measurements were used to calculate, according to Marcus theory, the outer-sphere solvent reorganization energy and the internal molecular reorganization energy.