Self-assembly, optical, thermal and electrochemical properties of bis-N-benzyl perylene diimide dye.

Flexible methylene containing N,N'-bis-(benzyl)-3,4,9,10-perylenebis(dicarboximide) (1) was synthesized. Self-assembled microstructures (hollow tubes, average length and width: 7.7 and 0.8 µm) of 1 were also prepared (T-1). Comparative studies of the optical, thermal and electrochemical properties of 1 and T-1 have been extensively carried out. The T-1 hallow tubes have shown extremely broad absorption in the near-infrared (300-800 nm) region (NIR) even in solution and intensified conductivity in the solid-state compared to 1. Under daylight and a UV lamp (365 nm), the emission colors of 1 are uniform pink and fluorescent yellow, respectively. Under the same conditions the colors of T-1 change to deep brown and glowing red, respectively. Two different isopotential points obtained through CV scans for 1 indicate the presence of two interconvertible chromophores within the system. The results clearly indicate that the anodic and cathodic processes are extremely intensified in the self-assembled T-1 structure.

Synthesis of a novel fluorescent amphiphilic chitosan biopolymer: photophysical and electrochemical behavior.

The present investigation describes for the first time, the synthesis and detailed characterization of a novel fluorescent and amphiphilic chitosan polymer (3) containing fluorescent peryleneimide chromophores for biomedical applications. The polymer 3 is moderately soluble in a wide range of organic solvents and aqueous solutions, unlike chitosan (2). The Mw of 3 and 2 determined by GPC were 467 kDa and 460 kDa, respectively. The photophysical and electrochemical properties measured in solution and solid states are engrossing. is soluble in the entire pH range and exhibits excimer emission above pH 5. In solution, 3 is electroactive but 2 is not. Whereas in the solid-state, 3 shows one quasi-reversible oxidation and reversible reduction step and 2 exhibits only one quasi-reversible oxidation step. Our results point out a new class of organic biopolymers that could yield promising potentials in many biomedical applications.

Drug Repurposing of FDA Compounds against α-Glucosidase for the Treatment of Type 2 Diabetes: Insights from Molecular Docking and Molecular Dynamics Simulations.

Type 2 diabetes mellitus is a chronic health problem that can be controlled by slowing one's carbohydrate metabolism by inhibiting α-glucosidase, an enzyme responsible for carbohydrate degradation. Currently, drugs for type 2 diabetes have limitations in terms of safety, efficiency, and potency, while cases are rapidly increasing. For this reason, the study planned and moved towards drug repurposing by utilizing food and drug administration (FDA)-approved drugs against α-glucosidase, and investigated the molecular mechanisms. The target protein was refined and optimized by introducing missing residues, and minimized to remove clashes to find the potential inhibitor against α-glucosidase. The most active compounds were selected after the docking study to generate a pharmacophore query for the virtual screening of FDA-approved drug molecules based on shape similarity. The analysis was performed using Autodock Vina (ADV)-based on binding affinities (-8.8 kcal/mol and -8.6 kcal/mol) and root-mean-square-deviation (RMSD) values (0.4 Å and 0.6 Å). Two of the most potent lead compounds were selected for a molecular dynamics (MD) simulation to determine the stability and specific interactions between receptor and ligand. The docking score, RMSD values, pharmacophore studies, and MD simulations revealed that two compounds, namely Trabectedin (ZINC000150338708) and Demeclocycline (ZINC000100036924), are potential inhibitors for α-glucosidase compared to standard inhibitors. These predictions showed that the FDA-approved molecules Trabectedin and Demeclocycline are potential suitable candidates for repurposing against type 2 diabetes. The in vitro studies showed that trabectedin was significantly effective with an IC50 of 1.263 ± 0.7 µM. Further investigation in the laboratory is needed to justify the safety of the drug to be used in vivo.

A new tunable light-emitting and π-stacked hexa-ethyleneglycol naphthalene-bisimide oligomer: synthesis, photophysics and electrochemical properties.

An oligomer (3) containing flexible hydrophilic hexa(ethylene glycol) and hydrophobic naphthalene-bisimide chromophores has been synthesized by a one-step condensation reaction and its photophysical and electrochemical properties were investigated. 3 was characterized through the data from NMR, IR, UV-vis, GPC, DSC, TGA, elemental analysis and cyclic voltammetry. The average molecular weight (M(w)) of 3 was 4430 g mol(-1). Intrinsic viscosity was measured as 0.28 dL g(-1) in m-cresol at 25 °C. It has high thermal stability (T(d) = 325 °C). Interestingly, compound 3 shows excimer-like emission in all kinds of solvents. The band gap energy (E(g)), LUMO and HOMO energy values in nonpolar and polar protic solvents were 2.71 eV/3.12 eV, -3.69 eV/-3.88 eV and -6.40 eV/-7.00 eV for 3, respectively. The oligomer showed concentration and solvent dependent fluorescent color tunability. Remarkably, the fluorescent colors of the excimer emissions at 10(-6) M concentration in CHCl(3), DMF and MeOH are light yellow, light blue-yellow and strong blue, respectively, and become more intense at higher concentrations. The excimer emission color in CHCl(3) and DMF is fluorescent yellow and changed to green in MeOH at 10(-4) M concentration. 3 shows two reversible reduction steps at -1.103 and -1.457 V (vs. ferrocene/ferrocenium) in nonpolar solvent CH(2)Cl(2) and only one at -0.917 V in (50:50) CH(3)OH-CH(3)CN binary solvent mixture with higher reversibility. Strong blue-shifts of emission band were noted in protic solvents, which confirm the existence of a negative solvatochromism probably due to protonation. The strong solvent-dependent photophysical and electrochemical properties, including the large shift of excimer emission maximum reflecting self-assembly mediated through hydrogen bonding and π-stacking interactions, make the oligomer a potential candidate for various photo-sensing applications.

Chiral substituent containing perylene monoanhydride monoimide and its highly soluble symmetrical diimide: synthesis, photophysics and electrochemistry from dilute solution to solid state.

A new chiral perylene monoanhydride monoimide (1) with a sterically hindered chiral amine was successfully synthesized for further selective functionalization at terminal positions. At the same time, the chiral perylene diimide (2) with the same amine has been synthesized. The synthesized products were characterized using the data from NMR, IR, MS, UV-vis, DSC, TGA, elemental analysis and cyclic and square wave voltammetry. Compound 2 shows an excellent solubility of 200 mg mL(-1) in chloroform. The band gap energy (Eg), LUMO and HOMO energy values were 2.28, -3.77 and -6.05 eV for 2, respectively in chloroform. In solid state, the band gap energy (Eg), LUMO and HOMO energy values were 1.96, -4.22 and -6.18 eV for 1 and 1.92, -4.13 and -6.05 eV for 2, respectively. Whereas 1 (solid state: -0.58 and -0.69 V vs. ferrocene/ferrocenium couple) and 2 (in chloroform: -1.03 and -1.22 V vs. ferrocene/ferrocenium couple) show two reversible reduction steps, 2 exhibits only one reversible wave (solid state: -0.67 V vs. ferrocene/ferrocenium couple). The diffusion coefficients were determined as 1.91 x 10(-7) and 8.47 x 10(-7) cm2 s(-1) for 1 and 2 in solid state, respectively, and 1.27 x 10(-5) cm2 s(-1) for 2 in solution. The solid state emission ability of the chiral products ( is much more emissive than ) remains a challenge for photonic, electronic and sensor applications. 1 and 2 showed high thermal stability. Efficient prevention of intermolecular pi-pi contacts of fluorophores results in an excellent fluorescence emission in solid state and solubility for 2.

Novel naphthalene diimides and a cyclophane thereof: synthesis, characterization, photophysical and electrochemical properties.

Three novel naphthalene diimides (1-3) and a cyclophane (4) containing two naphthalene diimide moieties were synthesized and characterized. In contrast to the absorption spectra, the emission spectra were strongly dependent on the solvent polarity. The excimer-like emission and low fluorescence rate constant suggest the formation of ground state complexes in DMF. All the compounds have low fluorescence quantum yields (0.001-0.012). They undergo reversible electron reduction and oxidation while deltaEp values depend strongly on solvent polarity. The LUMO energy values of 1 (3.76 eV), 2 (3.69 eV), and 3 (3.66 eV) vary with the substituent pattern. The structurally relatively rigid cyclophane 4 exhibits excellent thermal stability, a high glass transition temperature (tg, 102 degrees C) and a low LUMO energy value (3.59 eV). Compound 2 is insoluble in DMF at room temperature, but begins to dissolve at 37 degrees C and could therefore potentially serve as a sensor in temperature-sensing devices.