Phenolic −OH-Induced\nFluorescence and Chemoselectivity\nin a Triptycene-Based <i>trans</i>-Azo Oligomer for Sensing\nApplications

A novel triptycene-based <i>trans</i>-azo fluorescent\noligomer exhibiting phenolic groups has been designed. The presence\nof phenolic −OH in conjugation with the azo group rendered\nthe oligomer fluorescence active by keto–enol tautomerism,\nwhich was evidenced by quenching the fluorescence intensity of <b>TP1</b> in 1 M aq. NaOH. A green synthetic protocol was employed\nto synthesize this oligomer as a dark-brown solid, and it was characterized\nby using diverse analytical tools such as FTIR, <sup>13</sup>C-CPMAS\nNMR, GPC, FESEM, EDS, TGA, and PXRD techniques. FESEM and PXRD confirmed\nits existence as amorphous nanoclusters. The oligomer displayed efficient\nchemosensing properties toward the detection of picric acid with the\nLOD value of 391 nM. The specific recognition of PA in the presence\nof other explosives and the results of real water sample analysis\nfurther indicated the high efficacy of the <b>TP1</b> as a chemosensor.