Palladium-Catalyzed Synthesis of <i>trans</i>-4-(<i>N</i>,<i>N</i>-Bis(2-pyridyl)amino)stilbene. A New Intrinsic Fluoroionophore for Transition Metal Ions

Abstract

[reaction: see text] The title compound (1) has been synthesized via sequential Pd-catalyzed amination reactions and investigated as an intrinsic fluoroionophore. The efficiency in the synthesis of 1 strongly depends on the order of couplings among the substrates. Compound 1 displays fluorescence quenching upon the binding of transition metal ions, where the binding-triggered conformational twisting and in turn the inhibition of internal charge transfer (ICT) play an important role.