Zn(2+)-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 Zn(2+). 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 Zn(2+) 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.