Simple Pyrene Derivatives as Fluorescence Sensors for TNT and RDX in Micelles

Abstract

Various pyrene derivatives were synthesized and systematically examined in micelles. Synthesized mono and bispyrene derivatives were tested in micelles so that they displayed a strong excimer band and the excimer band was quenched in the presence of TNT and RDX. In the optimized condition, the binding constant for TNT of a simple dipyrene derivative 4 was increased up to 1.0 × 10 6 M −1 in cetyl trimethylammonium bromide (CTAB) micelles, which allowed for the detection of 2 ppb of TNT and 334 ppb of RDX by fluorescence titrations.

π-Electron rich small molecule sensors for the recognition of nitroaromatics

“…Unlike 28, molecular structure analysis of 29 revealed that it does not form such supramolecular polymeric structure due to the lack of required H-bonding interactions. Compounds 28─30 exhibited strong emission in solution with estimated quantum yields of Φ = 0.21 (28); 0.23 (29) and 0.47 (30). The fluorescence quenching titration study of 28─30 with picric acid 5 demonstrated that, as expected, the quenching efficiency followed the order 28>29>30.…”

“…The fluorescence quenching titration study of 28─30 with picric acid 5 demonstrated that, as expected, the quenching efficiency followed the order 28>29>30. The calculated quenching constants (K SV ) were 2100 M -1 (28); 200 M -1 (29) and 130 M -1 (30). In addition, similar titration study with a series of analytes indicated the largest quenching responses of 28─30 for NACs at 10 ppb level over other analytes BQ, BA, which were elicited poor fluorescence quenching.…”

“…28 A pyrene based sensor 8 showed two monomeric emissions 125 at 378 nm and 398 nm and one broad excimer emission at 484 nm. 29 Upon the addition of TNT to the solution of 8 in CTAB micelle caused decreased in intensity of both monomer and excimer emissions. The observed large quenching constant (K SV = 2.9 × 10 5 M -1 ) was attributed to the hydrophobic nature of 8.…”

“…6). Two analogues compounds 29 and 30 were also synthesized by replacing ─COOH in 28 with ─COOEt (29) and CH 3 (30) to 130 substantiate the role of H-bonding interaction on sensitivity of detection. Unlike 28, molecular structure analysis of 29 revealed that it does not form such supramolecular polymeric structure due to the lack of required H-bonding interactions.…”

Fluorescent Detection of 2,4‐DNT and 2,4,6‐TNT in Aqueous Media by Using Simple Water‐Soluble Pyrene Derivatives

“…[28] Gho andc o-authors reported unprecedentedly high binding constants due to the excimer fluorescencequenching by TNT( K sv TNT = 110 6 m À1 )w hile using micellar solutionso ft weezers-like pyrene derivative in semiaqueous conditions. [29] Herein, we report the synthesis and use of water-soluble pyrene derivatives 1-6 for the direct fluorescent detection of common explosives in aqueous solutions. The highs electivity and sensitivity have been confirmed by the enhanced fluorescence quenching of 1-6 in the presence of trace amountso f 2,4-DNT and 2,4,6-TNT.…”