Conjugated mesoporous perylene and triazine based oligomers for promising application towards N2 adsorption and fluorescence sensing of picric acid.

Introducing conjugated Mesoporous Perylene and triphenylamine based Triazine oligomers (M-TPI and D-TPI) for N₂ adsorption and fluorescence detection of explosive materials such as Picric acid. This has been synthesized from perylene 3,4,9,10-tetracarboxylic dianhydride with mono and di amino triazine and triphenylamine based compound using a simple polycondensation route. These oligomers are well analysed towards FT-IR, Solid-state NMR (CP-MAS), and HRMS technique. These oligomers have shown good thermal stability up to 280 ˚C from TGA analysis. The mesoporous of these oligomers was recognized from BET N₂ adsorption/desorption measurements and showed pore size and volume increased from 1.3 to 2 nm and 0.002–0.08 cm³/g before and after pyrolysis. Photophysical properties (UV–Vis and Fluorescence) reveal that absorption at 350 nm and emission at 513 nm and 505 nm. The optical band gap was found to be 1.7 eV and 1.6 eV and it was well correlated with DFT data. These oligomers dealt with polar solvents and observed a Bathochromic shift of fluorescence emission. In-depth studies of oligomers with various solvent fractions (THF/Water), luminescence intensity was increased leading to aggregation-induced enhanced emission (AIEE), and specifically 60–70% fractioned oligomers showed enormous emission. Further analysis from FE-SEM studies showed that the particles are well aggregated, and the size was measured in the range of 0.67–2.6 µm. AIEE helped to detect explosives (particularly picric acid) and the LOD determined as 1.48 × 10^–6 M and 1.196 × 10^–7 for M-TPI and D-TPI oligomers. These oligomers underwent practical application on real-water samples, demonstrating excellent recovery rates. These results highlight their efficacy for explosive applications, indicating their potential for significant real-world impact. Hence, the synthesized oligomers are well deserved for gas adsorption and explosive applications. [ABSTRACT FROM AUTHOR]