Fluorescence Modulation by Amines: Mechanistic Insights into Twisted Intramolecular Charge Transfer (TICT) and Beyond

Amine groups are common constituents of organic dyes and play important roles in tuning fluorescence properties. In particular, intensive research works have demonstrated the tendency capabilities amines influencing chromophore brightness. Such properties been explained by multiple mechanisms spanning from twisted intramolecular charge transfer (TICT) to energy gap law beyond, which introduce additional nonradiative dissipation pathways. this review, we aim provide a focused overview mechanistic insights mainly for TICT mechanism, accompanied few other less or influential quenching amine-containing fluorescent molecules. Various aspects current scientific findings including rational design synthesis chromophores, theoretical calculations, steady-state time-resolved electronic vibrational spectroscopies reviewed. These in-depth understandings how amine with diverse chemical structures at various atomic sites affect excited-state decay pathways will facilitate strategic targeted development fluorophores desired emission as versatile chemosensors broad applications.