A luminescent cyclic binuclear zinc–pamoate complex for highly selective and sensitive sensing of 2,4,6-trinitrophenol

A luminescent cyclic binuclear zinc–pamoate complex, [Zn2(PAM)2(1,3-PDA)2] (1), has been synthesized by self-assembly of Zn(II) ions, 4,4′-methylenebis(3-hydroxy-2-naphthalenecarboxylic acid) (H2PAM) and 1,3-propanediamine (1,3-PDA) under hydrothermal condition and characterized by elemental analysis, infrared spectroscopy, powder X-ray diffraction and single-crystal X-ray diffraction analysis. In 1, two Zn2+ ions are bridged by two PAM ligands to form a 24-membered ring binuclear structure. The emission of 1 could be quenched efficiently and selectively by 2,4,6-trinitrophenol(TNP), indicating that 1 can serve as a selective chemosensor for the detection of TNP via a fluorescence quenching mechanism.