A Highly Efficient Coordination Polymer for Selective Trapping and Sensing of Perrhenate/Pertechnetate

Area of Science:

• Materials Chemistry
• Coordination Polymers
• Sensing Technologies

Background:

• Perrhenate (ReO4-) contamination poses environmental and health risks.
• Development of selective and efficient adsorbents and sensors for perrhenate is crucial.
• Coordination polymers offer tunable structures for targeted applications.

Purpose of the Study:

• To synthesize and characterize a novel porous cationic Ag(I) coordination polymer.
• To evaluate its performance in perrhenate removal and selective sensing.
• To investigate the underlying mechanisms of sorption and sensing.

Main Methods:

• Synthesis of [Ag(1,2,4,5-p4b)](SbF6) (TJNU-302) using 1,2,4,5-tetra(pyridin-4-yl)benzene ligand.
• Sorption capacity and distribution coefficient (Kd) measurements.
• Selectivity studies in the presence of competing anions (CO3^2-, PO4^3-).
• Crystalline and solution-based fluorescence sensing of perrhenate.
• Single-crystal structure analysis and Density Functional Theory (DFT) calculations.

Main Results:

• TJNU-302 exhibits high sorption capacity (211 mg g^-1) and Kd (5.8 × 10^5 mL g^-1) for perrhenate.
• Demonstrates outstanding selectivity for perrhenate removal over carbonate and phosphate anions.
• Functions as a crystalline turn-off sensor for perrhenate under UV radiation.
• Shows efficient fluorescence quenching (86%) in water solution, outperforming existing sensors.
• Structural and DFT analyses elucidate the sorption and sensing mechanisms.

Conclusions:

• TJNU-302 is a highly effective material for perrhenate removal and sensing.
• Its porous cationic structure facilitates selective perrhenate uptake.
• The material's sensing capabilities can be utilized for developing test paper strips.
• Further research into coordination polymers for environmental remediation and sensing is warranted.