Sensitive Fluorescence Detection of Phthalates by Suppressing the Intramolecular Motion of Nitrophenyl Groups in Porous Crystalline Ribbons

A novel,
highly sensitive fluorescence sensor for phthalates is
developed by introducing nitrophenyl groups to a trifluorene molecule
that can form porous crystalline ribbons. On the basis of single-crystalline
analysis and theoretical calculations, we demonstrate that phthalate
molecules can diffuse into the caves of crystalline ribbons and effectively
suppress the rotation of nitrophenyl groups via noncovalent interactions
to enhance the emission. Because of this novel response mechanism,
fluorescence detection of phthalates with high sensitivity (the limit
of detection of widely used di­(2-ethylhexyl) phthalate (DEHP) is 0.03
ppb) and rapid reversible turn-on responses is achieved. Sensitive
detection of phthalates released from commercial polyvinyl chloride
(PVC) products further illustrate the utility of such a sensor in
in situ and real-world applications.