Selective Detection of Trinitrophenol by Amphiphilic Dimethylaminopyridine-Appended Zn(II)phthalocyanines at the Near-Infrared Region

Abstract

Novel amphiphilic Zn(II)phthalocyanines (ZnPcs) peripherally substituted with four and eight dimethylaminopyridinium units (ZnPc 1 and ZnPc 2 ) were synthesized by cyclotetramerization of the corresponding phthalonitriles. The effect of aggregation and photophysical (fluorescence quantum yields and lifetimes) and photochemical (singlet oxygen generation and photodegradation under light irradiation) properties was investigated. The chemosensing ability of ZnPcs toward explosive nitroaromatic compounds was explored in aqueous medium. This study demonstrates that ZnPc 1 and ZnPc 2 show fluorescence quenching behavior upon interaction with different nitro analytes and show unprecedented selectivity toward 2,4,6-trinitrophenol with a limit of detection (LOD) of 0.7–1.1 ppm with a high quenching rate constant ( K sv ) of 1.6–2.02 × 10 5 . The near-infrared (NIR) fluorescence in thin films was quenched efficiently because of the photoinduced electron-transfer process through strong intermolecular π–π and electrostatic interactions. The sensing process is highly reversible and free from the interference of other commonly encountered nitro analytes. Further, experiments were performed to demonstrate the use of ZnPcs as efficient heterogeneous photocatalysts in the reduction of nitro explosives. The smart dual performance of multicharged ZnPcs in aqueous media quantifies them as attractive candidates in developing sensor materials at the NIR region and to possibly convert the toxic explosives into useful scaffolds. These results provide an interesting perspective toward elaboration of stable fluorescent systems for the selective sensing behavior of nitro explosives and their facile heterogeneous catalytic behavior in the reduction reactions.

One-pot synthesis of poly(vinylpyrrolidone)-encapsulated color-emitting silicon quantum dots for sensitive and selective detection of 2,4,6-trinitrophenol

“…Compared with some previous TNP probes (Table S1, ESI†), the PVP-Si QDs showed moderate linear range and sensitivity for TNP detection; it is easy to prepare and advantageous in its comprehensive ability. 25–28,33,51–53…”

“…Compared with some previous TNP probes (Table S1, ESI †), the PVP-Si QDs showed moderate linear range and sensitivity for TNP detection; it is easy to prepare and advantageous in its comprehensive ability. [25][26][27][28]33,[51][52][53] Selectivity of the PVP-Si QDs for TNP sensing Zn 2+ , Hg 2+ , Cu 2+ , Cr 3+ , Fe 2+ and Al 3+ ) and anions (F À , Cl À , Br À , I À , CN À , SCN À , ClO ) were studied under the same test conditions. As shown in Fig.…”

“…Different analytical techniques such as electrochemical detection, mass spectrometry, Raman spectroscopy, mobility spectroscopy, neutron activation analysis, chromatography, infrared spectroscopy, surface-enhanced Raman spectroscopy, and X-ray imaging have been utilized in the detection of TNP. [28][29][30][31][32][33][34] However, most of these methods require expensive instruments, capable professionals, tedious operation, and even preconcentration before detecting trace explosives. 35 In recent years, the methods based on fluorescence colorimetric and spectroscopy have gained great attention due to their inexpensiveness, high sensitivity, and quick response.…”

Protonation- and electrostatic-interaction-based fluorescence probes for the selective detection of picric acid (2,4,6-trinitrophenol) – an explosive material

“…Further, the detection of vapor of picric acid by fluorescent probe can give advantage for the device formation. However, only in a couple of cases, thin films 108,109,111,120 of probe undergo fluorescence quenching with picric acid within couple of minutes and in other cases the probe deposited on TLC plate 53,89 or the solution of probe in THF-water 33 detect picric acid vapor.…”

Azine Steric Hindrances Switch Halogen Bonding to N‐Arylation upon Interplay with σ‐Hole Donating Haloarenenitriles

“…Some groups reported the intramolecular nucleophilic substitution of bromide or iodide in α-acyl substituted β-carboline system at elevated temperature (220°C), which give pyridodiindole quaternary salt. [74][75][76] A few examples of azines N-arylation by nitrile-containing reagents have been reported: three examples for chlorides, [77][78][79] one for bromides, [80] and no examples for iodides were found. Particularly, BNPN reacts with an excess of pyridine at RT to provide, presumably, the corresponding N-arylpyridinium salt; [80] the structure of the isolated product was postulated based exclusively 1 H NMR and elemental analyses data and no XRD study was performed.…”