Triphenylbenzene Sensor for Selective Detection of Picric Acid

Area of Science:

• Materials Science
• Analytical Chemistry
• Organic Chemistry

Background:

• Triphenylbenzene derivatives are explored for their photoluminescent properties.
• Development of selective sensors for explosive detection is crucial.

Purpose of the Study:

• To synthesize and characterize a C3-symmetric triphenylbenzene-based photoluminescent compound, [NHMe]3TAPB.
• To evaluate the potential of [NHMe]3TAPB as a selective fluorescent sensor for analytes like picric acid.

Main Methods:

• Synthesis of 1,3,5-tris(4'-(N-methylamino)phenyl) benzene ([NHMe]3TAPB) via mono-N-methylation of 1,3,5-tris(4'-aminophenyl) benzene (TAPB).
• Structural characterization of the synthesized compound.
• Fluorescence spectroscopy was used to assess sensing capabilities and selectivity towards various analytes, including picric acid (PA), TNT, DNT, and DNB.
• Fluorescence lifetime measurements were performed to elucidate the quenching mechanism.

Main Results:

• The synthesized compound [NHMe]3TAPB exhibits selective fluorescence sensing for picric acid (PA).
• A low detection limit of 2.25 ppm for PA was achieved (S/N=3).
• The sensor showed minimal response to other nitroaromatic compounds like TNT, DNT, and DNB.
• Selectivity is attributed to proton transfer and ground-state complex formation involving hydrogen bonding.
• Fluorescence quenching was determined to be static in nature.

Conclusions:

• [NHMe]3TAPB is a promising C3-symmetric photoluminescent material for selective picric acid detection.
• The sensor's mechanism involves proton transfer and hydrogen bonding interactions.
• The study highlights the potential of triphenylbenzene derivatives in developing advanced chemical sensors.