Photoinduced intramolecular charge transfer process of betaine pyridinium: A theoretical spectroscopic study

► TD-DFT is used to investigate the spectral properties of a pyridinium betaine. ► Very good agreement with experiment is reached for absorption and emission. ► S2 state is involved in the absorption band and S1 in the emission band. ► Solvatochromic effects are reproduced. ► Charge distribution and dipole moment evolutions upon photoexcitation are analyzed.