A pyrene-benzimidazole composed effective fluoride sensor: potential mimicking of a Boolean logic gateElectronic supplementary information (ESI) available. CCDC 1586465. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c8nj01011k

• Main Authors: Kushwaha, Archana, Patil, Sagar K, Das, Dipanwita
• Format: Journal Article
• Language: English
• Published: 29.05.2018
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/c8nj01011k

In this work, three benzimidazole derivatives incorporating 4- N , N ′-dimethylaminobenzene ( 1 ), pyrene ( 2 ) and anthracene ( 3 ) moieties, respectively, have been synthesized and characterized by analytical and spectroscopic techniques. All three receptors were probed as potential anion sensors. Receptor 2 detects F − ions selectively in the presence of various anions like Cl − , Br − , CN − , ClO 4 − , HSO 4 − , NO 3 − , PF 6 − , AcO − and H 2 PO 4 − as their tetrabutylammonium salts (TBA) where the drastic color change can be observed by the naked eye while the other two molecules were found to be unresponsive towards anions. The recognition aspects have been investigated by absorption, emission and 1 H NMR titration study. The sensing mechanism involves hydrogen bonding interaction between F − and an imidazole N-H proton at low concentration followed by deprotonation with the addition of excess F − ions, as confirmed by the HF 2 − signal in 1 H NMR spectra. The strong interaction between receptor 2 and F − ion has been revealed by a high binding constant value. The limit of detection (LOD) was found to be 1.63 × 10 −5 M. Based on the reversibility of the recognition event, we developed a potential "Write-Read-Erase-Read", i.e. recyclable memory function possessing multi-write ability. A highly selective fluoride sensor based on a pyrene benzimidazole unit was developed and studied for recyclable memory function.