Metal‐induced rearrangement of benzothiazoline ring: Synthesis and characterization of some new organoantimony(V) derivatives of N,O, and S atom containing schiff base ligands

Some new triphenylantimony(V) derivatives of Schiff bases having the composition have been synthesized by the equimolar reactions of Ph₃SbBr₂ with newly synthesized benzothiazoline ligands, (where R = C₆H₅(H₂L¹), 4‐BrC₆H₄(H₂L²), 4‐ClC₆H₄(H₂L³), 4‐CH₃‐OC₆H₄(H₂L⁴), 4‐CH₃C₆H₄(H₂L⁵)). The reaction proceeds with the rearrangement of benzothiazoline ring. All the derivatives have been characterized by elemental analyses, molecular weight measurements and their plausible structures have been proposed on the basis of IR and NMR (¹H and ¹³C) spectral studies. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:70–75, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20260     

Matching tyre size to weight, speed and power available for maximising pulling ability of agricultural tractors

The desirable weight-to-axle power ratio for agricultural tractors is determined by the necessity for the optimum utilisation of the available axle power to produce the required drawbar pull at a preselected slip. For a vehicle designed to operate in a given speed range, the weight-to-axle power ratio should be within a particular limit, so that a specific level of conversion efficiency can be maintained. In this paper attempts have been made to select suitable tyres for Indian two-wheel drive tractors operating in sandy clay loam soils on the basis of weight-to-power utiisation and maximum pull-to-optimum weight ratio at a preselected slip using the developed traction prediction equations. A comparison has also been made between the desired and actual weight on a single traction wheel and suitable tyre and tyre normally fitted in Indian two wheel drive tractors up to 35 kW.     

Analyses of Lattice Traffic Flow Model on a Gradient Highway

The optimal current difference lattice hydrodynamic model is extended to investigate the traffic flow dynamics on a unidirectional single lane gradient highway. The effect of slope on uphill/downhill highway is examined through linear stability analysis and shown that the slope significantly affects the stability region on the phase diagram.Using nonlinear stability analysis, the Burgers, Korteweg-deVries(KdV) and modified Korteweg-deVries(mKdV) equations are derived in stable, metastable and unstable region, respectively. The effect of reaction coefficient is examined and concluded that it plays an important role in suppressing the traffic jams on a gradient highway. The theoretical findings have been verified through numerical simulation which confirm that the slope on a gradient highway significantly influence the traffic dynamics and traffic jam can be suppressed efficiently by considering the optimal current difference effect in the new lattice model.     

High‐mobility solution‐processed zinc oxide thin films on silicon nitride

A high effective electron mobility of 33 cm² V^–1 s^–1 was achieved in solution‐processed undoped zinc oxide (ZnO) thin films. The introduction of silicon nitride (Si₃N₄) as growth substrate resulted in a mobility improvement by a factor of 2.5 with respect to the commonly used silicon oxide (SiO₂). The solution‐processed ZnO thin films grown on Si₃N₄, prepared by low‐pressure chemical vapor deposition, revealed bigger grain sizes, lower strain and better crystalline quality in comparison to the films grown on thermal SiO₂. These results show that the nucleation and growth mechanisms of solution‐processed films are substrate dependent and affect the final film structure accordingly. The substantial difference in electron mobilities suggests that, in addition to the grain morphology and crystalline structure effects, defect chemistry is a contributing factor that also depends on the particular substrate. In this respect, interface trap densities measured in high‐κ HfO₂/ZnO MOSCAPs were about ten times lower in those fabricated on Si₃N₄ substrates. (© 2014 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)

     

Preparation and Photocatalytic Performance of TiO2 Nanowire-Based Self-Supported Hybrid Membranes

Nowadays, the use of hybrid structures and multi-component materials is gaining ground in the fields of environmental protection, water treatment and removal of organic pollutants. This study describes promising, cheap and photoactive self-supported hybrid membranes as a possible solution for wastewater treatment applications. In the course of this research work, the photocatalytic performance of titania nanowire (TiO₂ NW)-based hybrid membranes in the adsorption and degradation of methylene blue (MB) under UV irradiation was investigated. Characterization techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), X-ray powder diffractometry (XRD) were used to study the morphology and surface of the as-prepared hybrid membranes. We tested the photocatalytic efficiency of the as-prepared membranes in decomposing methylene blue (MB) under UV light irradiation. The hybrid membranes achieved the removal of MB with a degradation efficiency of 90% in 60 min. The high efficiency can be attributed to the presence of binary components in the membrane that enhanced both the adsorption capability and the photocatalytic ability of the membranes. The results obtained suggest that multicomponent hybrid membranes could be promising candidates for future photocatalysis-based water treatment technologies that also take into account the principles of circular economy.     

Ligand-Enabled Palladium-Catalyzed Through-Space C−H Bond Activation via a Carbopalladation/1,4-Pd Migration/C−H Functionalization Sequence

We report, herein, a palladium-catalyzed cascade comprising carbopalladation, 1,4-Pd-migration and C(sp²)−C(sp²) bond formation to construct a variety of bis-heterocyclic frameworks in a single operational step. The methodology provides a direct approach to introduce an oxadiazole core at a remote location without any functional group obligation, with moderate to good yields.     

Titania-silica nanoparticles ensemblies assisted heterogeneous catalytic strategy for the synthesis of pharmacologically significant 2,3-diaryl-3,4-dihydroimidazo[4,5-b]indole scaffolds

Present paper elicits the multicomponent reaction (MCR) strategy assisted by titania nanoparticles hosted on silica (TiO₂.SiO₂ NPs) as heterogeneous catalyst to synthesize a series of pharmacologically significant 2,3-diaryl-3,4-dihydroimidazo[4,5-b]indole derivatives. To the best of our information, the use of isatin as one of the precursors was hitherto unreported. The decrease in reaction time, low catalyst loading, high product yield (up to 92%), and excellent reusability of the catalyst (up to 7 cycles) put this protocol under the umbrella of green chemistry tenets. Characterization of catalysts was achieved through a number of techniques viz., energy-dispersive X-ray (EDX) spectroscopy, field emission scanning electron microscopy (FESEM), powder X-ray diffraction (XRD), fourier transform infrared (FTIR) spectra of adsorbed pyridine, temperature-programmed desorption of ammonia, and porosity measurements by nitrogen adsorption (Brunauer–Emmett–Teller [BET] method). Also, the structures of synthesized compounds were corroborated on the basis of FTIR, nuclear magnetic resonance (NMR), mass, and elemental analyses data.