Improving the quantum yields of fluorophores by inhibiting twisted intramolecular charge transfer using electron-withdrawing group-functionalized piperidine auxochromes.

Herein, we present that the negative inductive effect exerted by electron-withdrawing groups, such as sulfone groups, can obviously improve the ionization potential of amino auxochromes, thereby effectively inhibiting twisted intramolecular charge transfer (TICT) and markedly improving the quantum yields of several families of fluorophores in aqueous solution.