Anilate Tethered Neutral Tetrahedral Pd(II) Cages Exhibiting Selective Encapsulation of Xylenes and Mesitylene

The design of porous materials for the recognition of multiple hydrocarbons is highly desirable for the energy-efficient separation and recognition of chemical feedstock. Herein, three new iso-structural porous discrete metal–organic cages of formula {[Pd₃(NiPr)₃PO]₄(R-AN)₆} (R-AN=anilate linkers) for the selective recognition of substituted aromatic hydrocarbons are reported. The tetrahedral cages 1 , 2 , and 3 containing anilate, chloranilate, and bromanilate linkers exhibited selective encapsulation of mesitylene, o-xylene, and p-xylene, respectively, over other analogous aromatic hydrocarbons. These selective encapsulations were driven by the variations in the portal diameters present at each of these cages and their interactions with the hydrocarbon guests. These observations are supported by mass spectrometry, NMR studies, and theoretical binding-energy calculations.     

Site-selective C–H nitration of N-aryl-7-azaindoles under palladium(II) catalysis

The site-selective C–H nitration reaction of 7-azaindoles with t-butyl nitrite under palladium catalysis is described. This protocol provides an efficient method for the construction of ortho-nitrated N-aryl-7-azaindoles with excellent site-selectivity and functional group compatibility. The formed 7-azaindole derivatives can be readily transformed into 7-azaindoles containing an aniline functional group under palladium-catalyzed hydrogenation conditions.     

Leading-edge flow criticality as a governing factor in leading-edge vortex initiation in unsteady airfoil flows

A leading-edge suction parameter (LESP) that is derived from potential flow theory as a measure of suction at the airfoil leading edge is used to study initiation of leading-edge vortex (LEV) formation in this article. The LESP hypothesis is presented, which states that LEV formation in unsteady flows for specified airfoil shape and Reynolds number occurs at a critical constant value of LESP, regardless of motion kinematics. This hypothesis is tested and validated against a large set of data from CFD and experimental studies of flows with LEV formation. The hypothesis is seen to hold except in cases with slow-rate kinematics which evince significant trailing-edge separation (which refers here to separation leading to reversed flow on the aft portion of the upper surface), thereby establishing the envelope of validity. The implication is that the critical LESP value for an airfoil–Reynolds number combination may be calibrated using CFD or experiment for just one motion and then employed to predict LEV initiation for any other (fast-rate) motion. It is also shown that the LESP concept may be used in an inverse mode to generate motion kinematics that would either prevent LEV formation or trigger the same as per aerodynamic requirements.     

High spin yrast states in even platinum isotopes

The high spin yrast states up toJ=20⁺ in^{184, 186}Pt and^{190, 192, 194}Pt are studied in a microscopic approach of variation with number-conserved projected states. The energy spectra, quadrupole moments andB(E2) values are calculated by employing the Hamiltonian with quadrupole plus pairing interactions. The results of the calculations are in fair agreement with the available experimental data.     

Evaluation of fuels for the synthesis of Li2CoMn3O8

Li₂CoMn₃O₈, a 5 V cathode material used in rechargeable lithium batteries, has been synthesized by adopting a novel technique of using fuels along with the nitrate reactants. The effect of the fuel on the synthesis of Li₂CoMn₃O₈ has been analyzed in terms of the physical and electrochemical properties of the final product formed by various methods such as solid-state carbonate fusion and the solution route using acetate and nitrate precursors. Powder X-ray diffraction FT IR spectrum, particle size, surface area and SEM analysis were carried out. The combustion method, also known as selfpropagating high temperature (SPHT) method, has been employed in the present study by using nitrate mixtures of the respective salts and a nitrogeneous fuel (urea or glycine) at a temperature of 300 °C for 3 hrs. The nitrate reactants without the addition of fuel gave only a deliquescent product even at elevated temperature (600 °C) thus indicating the necessity of fuels. Similar attempts using acetate reactants with and without the addition of nitrogeneous fuels were made separately in order to find out the necessity of fuel also in this case. The characterization of the product in terms of purity, single-phase formation and surface morphology suggested that the fuel played no role in the case of the acetate precursors. A comparative study was made on the products obtained by the acetate precursor, combustion method and the conventional carbonate method. Among the three methods, the combustion method with glycine as fuel yielded the spinel phase with high purity Li₂CoMn₃O₈ with superior electrochemical behavior both in terms of high cell voltage and good cycle life behavior.     

Chiral Schwinger model in curved space-time

We extend the method of path integrals to obtain the solution of the chiral Schwinger model in curved space-time and compare it with the flat space-time solution.     

Crystal growth,optical and thermal studies of nonlinear optical γ-glycine single crystal grown from lithium nitrate

Single crystals of the nonlinear material γ-glycine have been grown in the presence of lithium nitrate by slow-evaporation method. Structural characterization of the grown crystals was carried out by powder and single crystal X-ray diffraction (XRD) methods and it is observed that the samples crystallize in hexagonal system with non-centrosymmetric space groups. The modes of vibrations of different molecular groups present in glycine have been identified by spectral analyses. UV–visible transmittance study was performed to analyze optical transparency of γ-glycine crystals and found that the crystal was transparent in the entire visible-NIR region. Second harmonic generation (SHG) conversion efficiency has been estimated as 62 mV and the output power by the crystal was 1.72 times that of potassium dihydrogen phosphate (KDP) crystal. The thermal stability and decomposition of the sample have been studied by thermal analysis and it is observed that the γ-glycine crystal have good thermal stability.     

Validated HPLC method for simultaneous quantification of mutant IDH1/2 inhibitors (enasidenib,ivosidenib and vorasidenib) in mouse plasma: Application to a pharmacokinetic study

Isocitrate dehydrogenase (IDH) inhibitors comprise a novel class of anticancer drugs, which are approved to treat acute myeloid leukemia patients having mutations on IDH1/2. We report the development and validation of a high‐performance liquid chromatography (HPLC) method for the simultaneous quantitation of IDH inhibitors, namely enasidenib (EDB), ivosidenib (IDB) and vorasidenib (VDB), in mouse plasma as per the US Food and Drug Administration regulatory guidelines. The method involves extraction of EDB, IDB and VDB along with internal standard (IS; phenacetin) from mouse plasma (100 μl) using a simple protein precipitation process. The chromatographic analysis was performed on an HPLC system using a gradient mobile phase (comprising 10 mm ammonium acetate and acetonitrile in a flow‐gradient) and an X‐Terra Phenyl column. The UV detection wave length was set at λ_max 265 nm. EDB, IDB, VDB and the IS eluted at 7.36, 8.60, 9.50 and 5.12 min, respectively, with a total run time of 10 min. The calibration curve was linear over a concentration range of 0.20–12.5 μg/ml for EDB and 0.50–12.5 μg/ml for IDB and VDB (r² = ≥0.998 for all of the analytes). Validation results met the acceptance criteria. The validated HPLC method was successfully applied to a pharmacokinetic study in mice.     

Physical properties and processing conditions correlations of the ldpe/lldpe tubular blown films

Experiments are carried out to verify a theory developed to correlate the strain history of the polymer during film blowing to the ultimate physical properties of the film. The theory predicts that the amount of strain put into the film once it starts to freeze, defined as strain in the amorphous region and the plastic strain, has a dominant effect on the film properties. Two grades of low and linear low density polyethylene, experimental resins supplied by Mobil chemical company, were used to produce the blown film yielding a 1.25 mil film at the for all experimental runs. Film surface and bulk temperatures, along the machine direction and around the bubble, were measured using the infra-red techniques to identify the points where film starts to crystallize. A video digitization technique was used to measure the bubble kinematics. Film properties were measured using standard ASTM methods. The results indicate a correlation between the amount of strain and a measure of stress with ultimate physical properties of the blown film. This principle leads to the correlation of both the machine and transverse film properties on the same surface. The results obtained can potentially be exploited by designing the blown-film equipment and processing conditions such that optimal bubble stretching produces desired film properties.