Photophysical Properties of Novel Tryptanthrin Analogues
Abstract - Luminescent materials find useful applications in many fields, such as fluorescent sensors, in biological microscopy and optoelectronic devices. Highly emissive and stimuli sensitive excited electronic states are often characterised by intramolecular charge transfer (ICT), which is facilitated by the presence in π-conjugated structures of electron-withdrawing N-heterocycles, such as the indoloquinozaline ring, along with electron donating groups. Moreover, the availability of a nitrogen atom’s lone pair allows the indoloquinozaline ring to act as an efficient and stable complexing agent or as a base; the protonation of the nitrogen atom usually associates with a drastic modification in the electronic structure with subsequent dramatic change in the emission properties. This work reports on the synthesis and study of the photophysical properties of new small photoluminescent molecules based on the indoloquinozaline scaffold, highlighting their potential applications.
Keywords - Tryptanthrin; Photoluminescence; Intramolecular Charge-Transfer (ICT); DFT.