Gas bubbles grown on solids are more than simple vehicles for gas transport. They are charged particles with surfaces populated with exchangeable ions. We here unveil a gateway for alkali metal ion transport between oxygen bubbles and semi-conducting (iron oxide) and conducting (gold) surfaces. This gateway was identified by electrochemical impedance spectroscopy using an ultramicroelectrode in direct contact with bubbles pinned onto these solid surfaces. We show that this gateway is naturally present at open circuit potentials, and that negative electric potentials applied through the solid enhance ion transport. In contrast, positive potentials or contact with an insulator (polytetrafluoroethylene) attenuates transport. We propose that this gateway is generated by overlapping electric double layers of bubbles and surfaces of contrasting (electro)chemical potentials. Knowledge of this ion transfer phenomenon is essential for understanding electric shielding and reaction overpotential caused by bubbles on catalysts. This has especially important ramifications for predicting processes including mineral flotation, microfluidics, pore water geochemistry, and fuel cell technology.

Arylazo sulfonates (ArÀ N=NÀ SO 3 Na) have been found to undergo photografting on gold surface through both AuÀ N sp2 À and AuÀ C sp2 À bond formation. The functionalized materials have been fully characterized by infrared reflection absorption spectroscopy (IRRAS), Raman, XPS, DFT calculations and UV-Vis absorption spectroscopy. These methods permit to evidence aromatic substituents (IRRAS), the AuÀ N=N signature (Raman and XPS spectroscopy), and the bond dissociation energy values of the two linkages (DFT calculation). The grafting proceeds through two competitive paths, namely a stepwise reaction involving an aryl radical (for the formation of the AuÀ Ar bonds) and a concerted reaction on the surface of gold (for AuÀ N=NÀ Ar bond formation). The occurrence of an aryl radical upon irradiation has been fully evidenced by EPR spectroscopy. Finally, E/Z photoisomerisation of the N=N bonds present on prepared few layer films has been observed by means of UV-Vis absorption spectroscopy.

Developing a new effective anticancer agent becomes an urgent need to overcome of current drug-resistance. In this study we demonstrated that curcumin with heterocyclic moiety can function as an anticancer agent in a human. A new series of curcumin-based benzodiazepines, diazepines and diazoles were prepared using a simple one pot process. The process involved a condensation reaction of curcumin with various 1,2 diamino compounds and hydrazine. The structures of the prepared heterocycles were identified by the spectroscopic methods FT-IR, 1H NMR, and 13C NMR. The in vitro anticancer activities of the synthesized curcumin-based heterocycles against HeLa cancer cells were evaluated by the 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. The viability of HeLa cells was reduced in the range of 4.48- 14.57% within the studied concentrations. Curcumin-based diazepine 6 showed the highest cytotoxic effect on the HeLa cells at all concentrations. it reduced the viability of the tested HeLa cells in range of 4.48 % for the 400 μg /ml concentration to 4.95% for the 12.5 μg /ml concentration. Moreover, heterocyclic 6 showed the highest cytotoxic and cytostatic effect among the tested heterocyclics against Hela cells. It exhibited IC50 and a cytostatic effect of of 0.4572 and 0.08515 µg/ml, respectively at a nontoxic level, as the control L6 cells showed cytotoxic and cytostatic effect with IC50 values of 22.47 and 1.977 µg/ml, respectively. This study revealed that, the prepared curcumin-based compounds exhibit a promising anticancer activity against HeLa cancer cells at a nontoxic concentration.

Three synthesized Schiff base named 2,2’- (((2,2-dimethylpropane-1,3-diyl)bis(azanediyl)bis(methylene)disphenol (I1), 4,4’- (((2,2-dimethylpropane-1,3-diyl)bis(azanediyl)bis(methylene)bis(2-methoxyphenol) (I2) and 6,6’- (((2,2-dimethylpropane-1,3-diyl)bis(azanediyl)bis(methylene)bis(2-methoxyphenol) (I3) were evaluated as corrosion inhibitors for API 5L grade B steel in the artificial seawater by electrochemical impedance, polarization and Quantum chemical calculations methods. The results showed that all three compounds act as good inhibitors for carbon steel, but the I3 has the best inhibition efficiency of about 58% at 1mg/L. The results of density functional theory method were consistent with the experimental results.