Zn²⁺-induced conformational changes in a binaphthyl-pyrene derivative monitored by using fluorescence and CD spectroscopy

We have developed a unique binaphthyl-pyrene system 1, whose dihedral angle is reversibly modulated by the addition of Zn²⁺. Dihedral angle changes in this system were monitored by using circular dichroism (CD) and by an observed “off–on” fluorescence enhancement in aqueous solution. Owing to these changes, the presence of biologically important Zn²⁺ ions in samples can be readily monitored by employing CD and fluorescence spectroscopy. Finally, the experimental observations made in this effort are supported by the results of quantum mechanical calculations.