The architectonics of bitetrazole-based porous organic polymers for capturing iodine and fluorescence sensing to iodine and 4-nitrophenol

Two bitetrazole-based porous organic polymers (POPs), TBTZ and HBTZ, have been synthesized by nucleophilic substitution reactions with yields up to 79.08% and 78.81%, respectively. After a series of characterization, these two POPs show good chemical stability, thermal stability, and high pore properties. Through performance tests, we found that the two POPs show dual functions due to the introduction of bitetrazole, capturing iodine and fluorescence sensing I-2 and 4-nitrophenol (p-NP). First, owing to the plenty of nitrogen affinity sites, both TBTZ and HBTZ show excellent iodine adsorption with 3.54 and 5.66 g g(-1), respectively. The higher adsorption amount of HBTZ for iodine than TBTZ is due to the larger specific surface area of HBTZ than TBTZ, and stronger interaction of cyclophosphonitrile unit with iodine are than triazine ring with iodine. Second, on account of their excellent conjugated properties and nitrogen-enriched structures, TBTZ and HBTZ exhibit high sensitivity to I-2 and p-NP with K-SV of 3.97 x 10(3) and 5.49 x 10(4) L mol(-1) and limits of detection of 8.00 x 10(-10) and 5.46 x 10(-11) mol L-1, respectively. The former is the photo-induced electron transfer mechanism, while the latter is the energy transfer mechanism.