Enhanced photocatalytic activities of ZnO thin films: a comparative study of hybrid semiconductor nanomaterials

Nanostructure single ZnO, SnO₂, In₂O₃ and composite ZnO/SnO₂, ZnO/In₂O₃ and ZnO/SnO₂/In₂O₃ films were prepared using sol?Cgel method. The obtained composite films were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV?CVis spectroscopy. The photocatalytic activities of composite films were investigated using phenol (P), 2,4-dichlorophenol (2,4-DCP), 4-chlorophenol (4-CP) and 4-aminophenol (4-AP) as a model organic compounds under UV light irradiation. Hybrid semiconductor thin films showed a higher photocatalytic activity than single component ZnO, SnO₂ and In₂O₃ films. The substituted phenols degrade faster than phenol. The ease of degradation of phenols is different for each catalyst and the order of catalytic efficiency is also different for each phenol. The use of multiple components offered a higher control of their properties by varying the composition of the materials and related parameters such as morphology and interface. It was also found that the photocatalytic degradation of phenolic compounds on the composite films and single films followed pseudo-first order kinetics.     

Common tripled fixed point results in cone metric type spaces

In this paper, we prove some common tripled fixed point and tripled coincidence point results for contractive conditions in a cone metric type space. Our results extend, unify and generalize well-known results in the literature, in particular the recent results of Aydi et al. (Fixed Point Theory Appl 2012:134, 2012). Some examples are also presented to validate our obtained results and new concepts.     

Highly stereoselective construction of functionalized cyclopropanes from the reaction between acetylenic esters and C-H acids in the presence of triphenylarsine

A one-pot triphenylarsine-catalyzed synthesis of trans-cyclopropane derivatives is achieved by means of the reaction between acetylenic esters and C-H acids in the presence of triphenylarsine. This procedure is simple and proceeds under mild reaction conditions. Its success depends on the choice of solvent, temperature and C-H acid used.     

Evaluation of the anti-Leishmania major activity of Satureja bakhtiarica essential oil in vitro

Leishmaniasis is a painless chronic skin disease that is caused by the protozoan parasite Leishmania. Due to the importance of this disease and the side effects of chemical drugs, use of drugs of plant origin to treat Leishmaniasis is very important. In the present study, the chemical composition and the anti-Leishmania major activity of the essential oils obtained from Satureja bakhtiarica were evaluated in vitro. The oils were extracted using a Clevenger apparatus and then the chemical composition was analyzed by GC-MS. Promastigotes of L. major were cultured in both N.N.N and RPMI1640 media. GC-MS analysis showed 13 compounds, in which the major components were the phenolic (37.4%) compounds, thymol (22.6%) and p-cymene (19.3%). The essential oil of S. bakhtiarica showed higher activity against L. major than the standard anti-Leishmania drug, glucantime,. Perhaps because of the high concentration of phenolic compounds in the essential oil, all the parasites were killed after 24 hours. The essential oil from S. bakhtiarica is a potential plant drug against leishmaniasis. Further studies are necessary to evaluate this oil in animal models (in vivo) for future drug applications.     

Diastereoselective synthesis of chloro‐ and fluoro‐aniline containing phosphonate esters in a three‐component condensation

New phosphonate ester derivatives were obtained by in situ stereo‐specific reaction between triphenyl phosphite and dialkyl acetylenedicarboxylates in the presence of a series of halogenated anilines. Spectroscopic data and X‐ray crystallography analysis are in agreement with the gauche arrangement for the two vicinal protons in the structures. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:222–227, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20600     

Solvent Effects on the Chemoselectivity of Stable Phosphorus Ylides Involving a Sulfonamide

Hydrazine sulfonamide derivatives undergo a smooth reaction with dialkyl acetylenedicarboxylates in the presence of triphenylphosphine in varieties of solvent for generation of phosphorus ylides in a chemoselective manner.     

Infinitely many solutions for Steklov problems associated to non-homogeneous differential operators through Orlicz-Sobolev spaces

Employing variational methods and critical point theory, in an appropriate Orlicz-Sobolev setting, we establish the existence of infinitely many solutions for Steklov problems associated to non-homogeneous differential operators. We also provide some particular cases and a concrete example in order to illustrate the main results.     

γ‐Spiroiminolactone Synthesis by Reaction of Acetylenic Esters and α‐Dicarbonyl Compounds in the Presence of Aryl Isocyanide

The highly reactive 1∶1 intermediate produced in the reaction of aryl isocyanides and acetylenic esters was trapped by the α‐dicarbonyl compounds to yield γ‐spiroiminolactone derivatives in good yields.     

Reaction of Alkyl and Aryl Isocyanides with Floren‐9‐ones in the Presence of Acetylenic Esters: Preparation of γ‐Spiroiminolactones

The reactive 1∶1 intermediate generated by the addition of alkyl and aryl isocyanides to dialkyl acetylenedicarboxylate was trapped by 2,7‐dinitrofloren‐9‐one and floren‐9‐one to yield iminolactones in good yields.     

KF/Al2O3‐Mediated N‐Alkylation of Amines and Nitrogen Heterocycles and S‐Alkylation of Thiols

KF/Al₂O₃ efficiently catalyzes N‐alkylation of heterocyclic, primary, and secondary amines and S‐alkylation of thiols with a variety of alkyl halides. The N‐alkylation and S‐alkylation adducts were produced in good to excellent yields and in short times.