Publications

Seven fluorescent pyrazolines were synthesized. pyrazoline derivatives 5a-g was obtained by cyclization of chalcones 3a-g with phenylhydrazine using various synthetic methods including traditional method and green methodologies such as microwave heating and ultrasound irradiation. The reaction time, product yields are improved using the green methods. The structures were established based on IR spectra, 1H-, 13C NMR, elemental analysis, X-Ray Crystal Structure Determination, UV visible spectra and fluorescence spectra.). The seven compounds showed an excellent fluorescence in various solvents. The fluorescence properties such as quantum yield were measured. The substitution on both aromatic rings showed a remarkable influence on the fluorescence properties, this was rationalized using theoretical calculations of the charge density of both HOMO and LUMO orbitals. This new pyrazolines are potential fluorescent markers for biological systems.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Copper oxide-cadmium oxide nanocomposites (CuO-CdO NCs) were synthesized by solvothermal technique in a basic medium. CuO-CdO NCs were characterized using conventional techniques, such as Fourier Transform Infrared Spectroscopy (FTIR), UVâVisible Spectroscopy (UV/Vis), Field-Emission Scanning Electron Microscopy (FESEM), X-ray electron dispersive spectroscopy (XEDS), X-ray photoelectron spectroscopy (XPS), and powder X-ray diffraction (XRD). A selective and enzyme-less Bilirubin (BLR) sensor was developed with a thin-layer of NCs onto a glassy carbon electrode (GCE, surface area = 0.0316 cm2) using 5% nafion binders at room conditions. Improved electrochemical performances of higher sensitivity, lower detection limit, linear dynamic range (LDR), and long-term stability of preferred BLR were achieved by a reliable current-voltage (I-V) approach. The calibration curve was found linear (R2 = 0.9347) in a wide range of BLR concentration (10.0 pM ~ 10.0 mM). Based on the signal to noise ratio value of 3, the sensitivity and limit of detection (LOD) of the sensor were calculated as 95.0 pA μMâ1 cmâ2 and 1.0 ± 0.1 pM respectively. Solvothermally synthesized CuO-CdO NCs/GCE is an excellent advancement of developing a selective and sensitive BLR sensor by electrochemical approach and practically implemented in real sample applications. Keywords: CuO-CdO nanocomposites, Bilirubin biosensor, Glassy carbon electrode, Sensitivity, Real sample analysis, Health care field

Irradiation of colorless 1,3,3-trimethylspiro[indoline-2,3′-[3H]naphtho[2,1-b][1,4]oxazine] SO doped in PMMA and epoxy resin with UV light (at 366 nm) results in the formation of an intensely colored zwitterionic photomerocyanine PMC. The reverse reaction was photochemically induced by irradiation with white light. Photocoloration and photobleaching reactions follow a first-order rate equation. It was found that photocoloration rate constant of SO in PMMA film is greater than that in epoxy resin. On the other hand, the photobleaching rate constant is almost identical in both matrices. Spirooxazine doped in epoxy resin shows much better fatigue resistance than that doped in PMMA.

Purpose The purpose of this paper is to evaluate the photochromic performance of photochromic compounds in polymer matrices. Design/methodology/approach The polystyrene films doped with photochromic fulgide were prepared and the effect of UV irradiation were studied using spectrophotometer. The reversible reaction was effected using white light. The effect of heat was also determined. Findings A film of the green coloured fulgide 2‐E doped in polystyrene polymer was irradiated with UV light (366 nm), the film turned blue. The latter colour was partially switched back to the original green colour when the film was irradiated with a white light. Increasing the annealing temperatures, increases the percentage conversion of 2‐C to 2‐E . The observed large bathochromic shifts in λ max of 2‐C and the partial conversion of 2‐C to 2‐E were rationalised on the bases of electronic and steric effects. It was found that both isomers 2‐C and 2‐E absorbed white light and they interconvert. The kinetics of photocoloration and photobleaching processes were followed spectrophotometrically by monitoring the absorbance of the ring closed product 2‐C at its λ max of 620 nm. The apparent first‐order rate constants for both processes were determined. It was found that there was slight variation in the rate constant for photocoloration reaction with annealing temperature. On the other hand, the apparent first‐order rate constant of the photobleaching reaction decreases with increasing the annealing temperature. Research limitations/implications The polystyrene polymer doped photochromic fulgides described in the present paper was prepared and studied. The principle of study established can be applied to any type of polymer or to any type of photochromic compounds. Practical implications The photochromic materials developed can be used for different applications, such as coatings and holography. Originality/value The method developed may be used to enhance the performance of photochromic materials.

Strontium oxide nanoparticle decorated carbon nanotube nanocomposites (SrO·CNT NCs) were prepared in alkaline medium using a wet-chemical technique at low temperature.