Synthesis, Crystal Structure and Optical Properties of 2-(3-(Hexyloxy)-5-Methylphenoxy)-N-(4-Nitrophenyl)acetamide for Anion Detection

In this study, 2-(3-(hexyloxy)-5-methylphenoxy)-N-(4-nitrophenyl)acetamide (sensor L1) was synthesized and characterized by FT–IR, ESI–MS, 1H and 13C NMR spectroscopy, elemental analysis, and single crystal X-ray techniques. The crystal structure and space group of sensor L1 was monoclinic and P21, respectively. The crystal packing of sensor L1 was dominantly linked by two strong hydrogen bonds forming a six membered ring pattern. The binding properties of sensor L1 and various anions (F−, Cl−, Br−, CH3COO−, C6H5COO−, and H2PO4−) were investigated by UV–Vis and 1H NMR spectroscopy in DMSO. The proton resonance signals of sensor L1 and F− greatly changed positions when compared to those of anions. The solution color of sensor L1 changed from pale yellow to orange in the presence of F−. The UV–Vis results indicate that sensor L1 and F− ions underwent an internal charge transfer process. The stoichiometric complex was confirmed by Job’s method, revealing a 1:1 formation for sensor L1 and fluoride. Our results show that sensor L1 is highly selective for fluoride ions over other anions.

A benzothiazole-based fluorescence turn-on sensor for copper(II)

A new benzothiazole-based chemosensor BTN (1-((Z)-(((E)-3-methylbenzo[d]thiazol-2(3H)-ylidene)hydrazono)methyl)naphthalen-2-ol) was synthesized for the detection of Cu2+. BTN could detect Cu2+ with “off-on” fluorescent response from colorless to yellow irrespective of presence of other cations. Limit of detection for Cu2+ was determined to be 3.3 µM. Binding ratio of BTN and Cu2+ turned out to be a 1:1 with the analysis of Job plot and ESI-MS. Sensing feature of Cu2+ by BTN was explained with theoretical calculations, which might be owing to internal charge transfer and chelation-enhanced fluorescence processes.

Ultrafast synthesis of near-zero-cost S-doped Ni(OH)2 on C3N5 under ambient conditions with enhanced photocatalytic activity

2D S–Ni(OH)2 is facially planted on 2D C3N5 at room temperature in 30 minutes via a reaction between Ni(NO3)2 and Na2S in aqueous solution. Due to quick internal charge transfer efficiency, the hybrid is highly efficient for photocatalytic H2 production.

A molecular tailoring approach – a new guide to quantify the energy of push–pull effects: a case study on (E)-3-(1H-pyrrol-2-yl)prop-2-enones

We report a new approach to quantify the push–pull effect in molecules with internal charge transfer.

Quantifying internal charge transfer and mixed ion-electron transfer in conjugated radical polymers

Conjugated radical polymers can exhibit internal electron transfer depending on the radical loading.

Cost-effective approach to detect Cu(ii) and Hg(ii) by integrating a smartphone with the colorimetric response from a NBD-benzimidazole based dyad

A new optical chemosensor N1 was designed and synthesized by condensing 4-chloro-7-nitrobenzofurazan with 2-aminophenylbenzimidazole. In CH3OH : H2O (1 : 1, v/v) medium, sensor N1 exhibited high selectivity and sensitivity towards Cu2+ and Hg2+ ions by showing a distinct colour change from pale yellow to pink due to the internal charge transfer occurring between the sensor N1 and the Cu2+/Hg2+ ions upon complexation in 1 : 1 stoichiometry.

Recent Progress on the Evolution of Pourbaix Sensors: Molecular Logic Gates for Protons and Oxidants

Recent progress in the area of molecular logic, in particular molecules capable of sensing for acidity and oxidizability, are gathered together in this short review. Originally proposed as AND logic gates that provide a high fluorescence output when simultaneously protonated and oxidized, the concept has been extended from two-input to three-input variants and to include molecules that function as INHIBIT logic gates. Photochemical concepts such as photoinduced electron transfer (PET) and internal charge transfer (ICT) are exploited as favorite design concepts. This review highlights the evolution of Pourbaix sensors with anthracene, pyrazoline, and naphthalimide fluorophores. Future applications abound in various disciplines from corrosion science, material science, geochemistry to cell imaging.