Bicyclic 1,3a,6a-Triazapentalene Chromophores: Synthesis, Spectroscopy and Their Use as Fluorescent Sensors and Probes

The 1,3a,6a-triazapentalene (TAP) is an aromatic heterocyclic fluorescent dye with interesting features such as its small size, large Stokes shift, solvatochromism, and emission wavelengths that are spread across the visible spectrum. TAPs have been synthesized via different synthetic strategies involving click?cyclization?aromatization domino reactions, gold-catalyzed cyclization of propargyl triazoles or triazolization acetophenones. As a result, diverse substitution patterns were obtained, showing varying fluorescence properties. Based on these properties, several selected studied imaging probes in living cells sensors. This mini review provides overview research bicyclic does not comment literature about benzo otherwise fused systems. methodologies for preparation TAPs, substituent effects behavior TAP core element biological sensors discussed.