Synthesis, optical properties and self-assemblies of three novel asymmetrical perylene diimides modified with functional hydrogen bonding groups at bay positions

Three new perylene diimides modified with functioned hydrogen bonding groups at bay positions were successfully prepared. Their optical properties and self-assemblies on HOPG were investigated.

Perylene diimide-based treatment and diagnosis of diseases

Integrated treatment using imaging technology to monitor biological processes for the precise treatment and diagnosis of diseases to improve treatment outcomes is becoming a hot topic. Accordingly, perylene diimide (PDI) has excellent photothermal conversion and photostability, which can be used as a good material for disease treatment and diagnosis. Herein, we review the latest research progress on the real-time diagnosis of related diseases based on perylene diimide probes in the aspects of bioimaging, detection of biomarkers and determination of the pH in living cells. Furthermore, perylene diimide-based multifunctional nano-delivery systems are particularly emphasized, showing great therapeutic potential in the field of image-guided combination therapy in tumor therapy. Finally, the great opportunities and challenges still faced by perylene diimide before entering the clinic are comprehensively analyzed.

Unraveling the electrochemical and spectroscopic properties of neutral and negatively charged perylene tetraethylesters

A detailed investigation of the energy levels of perylene-3,4,9,10-tetracarboxylic tetraethylester as a representative compound for the whole family of perylene esters was performed. It was revealed via electrochemical measurements that one oxidation and two reductions take place. The bandgaps determined via the electrochemical approach are in good agreement with the optical bandgap obtained from the absorption spectra via a Tauc plot. In addition, absorption spectra in dependence of the electrochemical potential were the basis for extensive quantum-chemical calculations of the neutral, monoanionic, and dianionic molecules. For this purpose, calculations based on density functional theory were compared with post-Hartree–Fock methods and the CAM-B3LYP functional proved to be the most reliable choice for the calculation of absorption spectra. Furthermore, spectral features found experimentally could be reproduced with vibronic calculations and allowed to understand their origins. In particular, the two lowest energy absorption bands of the anion are not caused by absorption of two distinct electronic states, which might have been expected from vertical excitation calculations, but both states exhibit a strong vibronic progression resulting in contributions to both bands.

Imaging of lysosomal pH changes with a novel quinoline/benzothiazole probe

A fluorescent pH probe BTVQ for imaging lysosomal pH fluctuations in live cells and extreme acidity in E. coli cells.

Novel fluorescent probes for the fluoride anion based on hydroxy-substituted perylene tetra-(alkoxycarbonyl) derivatives

The fluoride anion (F⁻) sensing abilities of 1-hydroxyl-3,4,9,10-tetra (n-butoxyloxycarbonyl) perylene (probe 1) and 1-hydroxyl-mono-five-membered S-heterocyclic annulated tetra (n-butoxyloxycarbonyl) perylene (probe 2) were studied through visual detection experiments, UV-Vis, fluorescence, and ¹H NMR titrations. The probes were sensitive and selective for distinguishing F⁻ from other anions (Cl⁻, Br⁻, I⁻, SO₄⁻, PF₆⁻, H₂PO₄⁻, BF₄⁻, ClO₄⁻, OH⁻, CH₃COO⁻, and HPO₄²⁻) through a change of UV-Vis and fluorescence spectra. The absorption and fluorescence emission properties of the probes arise from the intermolecular proton transfer (IPT) process between a hydrogen atom on the phenolic O position of probe and the F⁻ anion. The sensing mechanism was supported by theoretical investigation. Moreover, probe-based test strips can conveniently detect F⁻ without any additional equipment, and they can be used as fluorescent probes for monitoring F⁻ in living cells.

The fluoride anion (F⁻) sensing abilities of two fluorescent probes based on hydroxy-substituted perylene tetra-(alkoxycarbonyl) derivatives were studied through visual detection experiment, UV-Vis, fluorescence, and ¹H NMR titrations.