Formation of nano-hillocks by impact of swift heavy ions on thin films of TiO2

Amorphous thin films of TiO₂ are irradiated by swift heavy ion (SHI) beam. Surface topography is studied by atomic force microscopy (AFM). Formation of nanosized oblate hillocks on the surface of irradiated films is investigated by AFM studies. After irradiation, amorphous to crystalline phase transition is observed in glancing angle X-ray diffraction (GAXRD) and Raman spectroscopy studies. Photoluminescence (PL)-spectroscopy is carried out for optical characterization. Threshold value necessary for emergence of hillocks is estimated.     

A conventional and solid-state synthesis,biological activity,and molecular docking studies of 6-arylbenzo[4,5]imidazo[1,2-a] [1,8]naphthyridin-10-ols

An effective, practical, and simple approach toward the preparation of highly-substituted 6-arylbenzo[4, 5]imidazo[1,2-a][1,8]naphthyridin-10-ols 6(a-h) by the reaction of 3-aryl-1,8-naphthyridin-2-amines 3(a-h) with benzoquinone 4 in acid catalyzed cyclization under solid-state method, as well as conventional conditions, has been described. The products are obtained in good yields and in a solid of high purity. The major advantages of solid states are easy workup, low costs, short reaction time, good efficacy, and environment-friendly procedure. The newly synthesized compounds were thoroughly characterized using spectral data and elemental analyses. All compounds were screened for their biological evaluation. Predominantly 6b and 6c compounds showed the highest antibacterial activity. Moreover, all the synthesized compounds were docked against topoisomerase II DNA gyrase enzyme.     

Electrospun Hierarchical CaCo2O4 Nanofibers with Excellent Lithium Storage Properties

Hierarchical CaCo₂O₄ nanofibers (denoted as CCO‐NFs) with a unique hierarchical structure have been prepared by a facile electrospinning method and subsequent calcination in air. The as‐prepared CCO‐NFs are composed of well‐defined ultrathin nanoplates that arrange themselves in an oriented manner to form one‐dimensional (1D) hierarchical structures. The controllable formation process and possible formation mechanism are also discussed. Moreover, as a demonstration of the functional properties of such hierarchical architecture, the 1D hierarchical CCO‐NFs were investigated as materials for lithium‐ion batteries (LIBs) anode; they not only delivers a high reversible capacity of 650 mAh g^?1 at a current of 100 mA g^?1 and with 99.6 % capacity retention over 60 cycles, but they also show excellent rate capability with respect to counterpart nanoplates‐in‐nanofibers and nanoplates. The high specific surface areas as well as the unique feature of hierarchical structures are probably responsible for the enhanced electrochemical performance. Considering their facile preparation and good lithium storage properties, 1D hierarchical CCO‐NFs will hold promise in practical LIBs.     

Phase transition studies in (p-n-phenylbenzylidene)-p-alkoxy anilines

The variation in density with temperature in seven compounds of p-n-(phenyl benzylidene)-p-alkoxy anilines, PBnOA homologous series has been carried out. The compounds with the alkoxy chain number, n = 1, 3–8, exhibit monovariant nematic phase N (n = 1 and 3), bi-variant NB (n = 4–6) and tri-variant NAB (n = 7 and 8) phases. The density and thermal expansion coefficient results reveal that the phase transitions present viz, isotropic to nematic, nematic to SmA, nematic to SmB, nematic to solid crystal and SmA to SmB in these compounds show first-order nature as expected. Further, these results reveal that all the parameters show characteristic change in the vicinity of the phase transformation. The results are discussed in light of the body of the data available.     

Effect of molybdenum doping on the electrochromic properties of tungsten oxide thin films by RF magnetron sputtering

Thin films of pure and molybdenum (Mo)-doped tungsten trioxide (WO₃) were deposited on indium tin oxide (ITO)-coated glass and Corning glass substrates by RF magnetron sputtering technique. The effect of Mo doping on the structural, morphological, optical and electrochromic properties of WO₃ films was studied systematically. The energy dispersive X-ray analysis (EDAX) revealed that the films consist of molybdenum concentrations from 0 to 2 at.%. X-ray diffraction (XRD) studies indicated that with the increase of Mo concentration the structural phase transformation takes place from polycrystalline to amorphous phase. The crystallite size of the films decreased from 24 to 12 nm with increase of doping concentration of Mo in WO₃. Scanning electron microscope (SEM) analysis revealed that Mo dopant led to significant changes in the surface morphology of the films. The electrochemical and electrochromic performance of the pure and Mo-doped WO₃ were studied. The WO₃ films formed with 1.3 at.% Mo dopant concentration exhibited high optical modulation of 44.3 % and coloration efficiency of 42.5 cm²/C.     

Development of a New Analytical Method for Determination of Related Components in Nateglinide

An isocratic reverse phase liquid chromatographic (RP-LC) assay method has been developed for the quantitative determination of nateglinide and its related components namely imp-1 and imp-2 in bulk drug and in pharmaceutical dosage form, used for the treatment of type II diabetes mellitus. The developed method is stability indicating and also can be used for stability testing. The chromatographic separation was achieved on C-8, 150 × 4.6 mm, 3.5 μm stationary phase. The LC method employs solution A as mobile phase. Solution A contains a mixture of phosphate buffer pH 3.0: acetonitrile (50:50 v/v). The flow rate was 1.0 mL min⁻¹ and the detection wavelength was 210 nm. In the developed LC method the resolution between nateglinide and its potential impurities namely imp-1 and imp-2 was found to be greater than 5.0. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation. Considerable degradation was found to occur in acid medium, alkaline medium and oxidative stress conditions. The stress samples were assayed against a qualified reference standard and the mass balance was found close to 99.2%. The developed RP-LC method was validated with respect to linearity, accuracy, precision and robustness.     

A novel biomimetic condensation of 2-deoxyribose, aryl amine and acetyl acetone to bicyclic aminols catalyzed by InCl3

2-Deoxyribose, an aryl amine and acetyl acetone undergo smooth cyclocondensation in the presence of 10 mol % of InCl₃ under mild conditions to afford the corresponding sugar-derived bicyclic aminols in good yields with moderate diastereoselectivity. This reaction is reminiscent of the celebrated tropinone synthesis of Robinson. The structures of the products are established by using various NMR experiments and X-ray crystallographic studies.