Structural and optical properties of ZnSe thin films stacked with PbSe submonolayers

Structural and optical properties of Zinc Selenide (ZnSe) thin films stacked with multiple Lead Selenide (PbSe) submonolayers (ML) were studied. Thermal evaporation was preferred to produce ZnSe–PbSe thin films with the PbSe ML thickness ranges from 2.5 to 10 nm. Polycrystalline nature of the ZnSe was revealed through high resolution X-ray diffractometer measurement. The development of micro strain at the interfaces with increasing PbSe ML thickness was observed. A cross-sectional TEM image shows well-ordered periodicity and reproducibility of the layer thickness. The enhancement of optical absorption of ZnSe was identified upon stacking of PbSe ML. The evidence for quantum confinement in PbSe ML was revealed by the obtained red shift in band gap (2.5–1.8 eV) values as well as photoluminescence emission at 1,071 nm. The presence of tensile strain in the ZnSe layers upon staking of PbSe ML was discussed by the shift in LO phonon modes in Raman spectra.     

An expedient synthesis of spirooxindoles incorporating 2-amino pyran-3-carbonitrile unit employing dialkyl acetone-1,3-dicarboxylates

Spirooxindoles are a class of molecules possessing significant biological effects such as antiviral, antifungal, antibacterial and anticancer properties. Herein we report a series of spirooxindole molecules having 2-amino pyran-3-carbonitrile and with two ester groups. These molecules were prepared by the reaction of dialkyl acetone-1,3-dicarboxylate and isatilidenes in the presence of triethyl amine.     

Silver-attached reduced graphene oxide nanocomposite as an eco-friendly photocatalyst for organic dye degradation

Research on Chemical Intermediates - Dye effluents play a major role in polluting water bodies, and various treatment technologies are being used for their removal. Among these methods, green...     

Development and validation of a liquid chromatographic method for monitoring of process-related synthetic organic impurities of profenofos in technical products

A simple and rapid reversed-phase high-performance liquid chromatographic method for the monitoring of process-related synthetic organic impurities of profenofos (PFS) is developed. Impurities are separated and determined on a reversed-phase Hypersil C(18) column using gradient elution of 50 mM ammonium formate buffer-acetonitrile as a mobile phase and detection at 230 nm at ambient temperature. The method is validated with respect to accuracy, precision, linearity, and limits of detection and quantitation. The method is found to be suitable not only for monitoring the reactions involved in the process development of PFS, but also quality assurance, as it can detect impurities at the level of 1.5 x 10(-8) g.