ESIPT or not ESIPT? Revisiting recent results on 2,1,3-benzothiadiazole under the TD-DFT light

Abstract

Recently, the spectroscopic signatures of amino-substituted benzothiadiazoles were investigated by complementary experimental and theoretical approaches [Neto et al., RSC Adv., 2012, 2, 1524–1532]. It was concluded that these molecules were exhibiting excited-state intramolecular proton transfer. In this communication, we revisit these results using a state-of-the-art time-dependent density functional theory approach which provides a complete explanation to the spectroscopic observations.