Facile Synthesis of Benzotriazole Derivatives Using Nanoparticles of Organosilane-Based Nitrite Ionic Liquid Immobilized on Silica and Two Room-Temperature Nitrite Ionic Liquids

Nanoparticles of organosilane-based nitrite ionic liquid immobilized on silica, 1-butyl-3-methylimidazolium nitrite, and 1-(3-trimethoxysilylpropyl)-3-methylimidazolium nitrite were used as effective reagents for the preparation of benzotriazole derivatives from 1,2-diaminobenzenes at room temperature under mild solvent-free conditions. These ionic liquids play as nitrosonium sources in this procedure.1,2-Diaminobenzene derivatives have been treated with ionic liquids to give the related diaminobenzenes in very good to excellent yields in short reaction times.

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Oxidative coupling of methane over （Na2WO4＋Mn or Ce）/SiO2 catalysts： In situ measurement of electrical conductivity

The effects of manganese oxide or ceria promoters on the performance of Na2WO4/SiO2 catalysts for oxidative coupling of methane (OCM) are reported. The OCM reaction was performed in a continuous-flow microreactor at 800 ℃, atmospheric pressure and under GHSV = 13200 ml gC-1at h-1. Catalysts were characterized by in situ conductivity measurement, FT-IR spectroscopy, XRD, SEM and temperature programmed reduction analysis. Manganese oxide promoted Na2WO4/SiO2 is considered as one of the active and selective ca...     

A facile and efficient addition reaction of nitrogen‐containing heterocyclic compounds with DMAD under neat conditions

A simple and efficient method was developed for the reaction of dimethyl acetylenedicarboxylate with benzothiazole, isoquinoline, quinoline, 3‐bromopyridine, pyridine, benzoxazole, benzimidazole, and 5,6‐dimethyl benzimidazole for the high‐yield synthesis of the related heterocyclic products ( 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ) in very short reaction time under neat procedure. The reaction of isoquinoline, 3‐bromopyridine, and pyridine afforded to diastereomeric mixtures of products 2 , 4 , and 5 , respectively. However, only one isomer of products 1 , 3 , 6 , 7 , and 8 were identified from the reaction of benzothiazole, quinoline, benzoxazole, benzimidazole, and 5,6‐dimethyl benzimidazole, respectively. Benzotriazole afforded to product 9 under these conditions. For comparison, the reactions were examined in different reaction mediums and/or under microwave irradiation. J. Heterocyclic Chem., (2011).     

Laser-induced forward transfer of intact chalcogenide thin films: resultant morphology and thermoelectric properties

We present a laser-based transfer method for the novel application of fabricating elements for planar thermoelectric devices. Thin films of thermoelectric chalcogenides (Bi₂Te₃, Bi₂Se₃ and Bi_0.5Sb_1.5Te₃) were printed via laser-induced forward transfer (LIFT) onto polymer-coated substrates over large areas of up to ～15 mm² in size. A morphological study showed that it was possible to partially preserve the polycrystalline structure of the transferred films. The films’ Seebeck coefficients after LIFT transfer were measured and resulted in ?49±1 μV/K, ?93±8 μV/K and 142±3 μV/K for Bi₂Te₃, Bi₂Se₃ and Bi_0.5Sb_1.5Te₃, respectively, which were found to be ～23±6 % lower compared to their initial values. This demonstration shows that LIFT is suitable to transfer sensitive, functional semiconductor materials over areas up to ～15 mm² with minimal damage onto a non-standard polymer-coated substrate.     

Mutual interplay between pnicogen–π and tetrel bond in PF<Subscript>3</Subscript>⊥X–Pyr…SiH<Subscript>3</Subscript>CN complexes: NMR,SAPT, AIM,NBO, and MEP analysis

The mutual interplay between pnicogen–π and tetrel bond in the formation of PF₃⊥X–Pyr…SiH₃CN ternary complexes has been investigated via a computational chemistry at MP2/aug-cc-pVDZ level of theory. We proved by computational NMR data the effect of electron-withdrawing and electron-donating substituents on ^1tJ(N-Si) across ¹⁵N...³⁵Si tetrel bonds was investigated at M06-2X/aug-cc-pVDZ levels of theory in PF₃⊥CN–Pyr…SiH₃CN complex. The nature of the interactions has been studied by means of symmetry-adapted perturbation theory (SAPT) and molecular electrostatic potentials (MEP). The electrostatic interaction played a major role in the change of tetrel bond interaction strength in the X–Pyr…SiH₃CN binary systems, whereas the change of pnicogen–π strength in the PF₃⊥X–Pyr complexes was caused jointly by the dispersion interactions. Energy decomposition indicates that the percentage of the electrostatic term in the tetrel bond system constitutes in the total attractive binding energies, while the percentage of the dispersion term in the pnicogen bonding constitutes in the attractive binding energies. In addition, atoms in molecules (AIM) and natural bond orbital (NBO) analyses were also performed to unveil the mechanism of these interactions in the title complexes.     

Antibacterial activity of the essential oil and main components of two Dracocephalum species from Iran

The antibacterial activity of Dracocephalum polychaetum and D. surmandinum essential oils and two main components were investigated. Essential oils of the plants were analysed by GC and GC-MS. Twenty-three components were characterised in the essential oil of D. polychaetum. The oil was rich in oxygenated (73.1%) and hydrocarbon (25.0%) monoterpenes including perilla aldehyde (63.4 %) and limonene (22.1%) as the major constituents. From 25 identified compounds (97.8%) in the oil of D. surmandinum perilla aldehyde (54.3%) and limonene (30.1%) were the main constituents. The bioassays exhibited that all of the Gram-positive and Gram-negative bacteria tested were highly inhibited in the presence of the oils and main components investigated. The most sensitive microorganism to the oils was found to be Staphylococcus epidermidis with the lowest MIC value of 0.3?mgmL(-1). The resistant Gram-negative Pseudomonas aeruginosa was highly inhibited by the oil of D. polychaetum with MIC value of 2.4?mgmL(-1).     

Methane hydrate stability in the presence of water-soluble hydroxyalkyl cellulose

The effect of low-dosage water-soluble hydroxyethyl cellulose (approximate MW～90,000 and 250,000) as a member of hydroxyalkyl cellulosic polymer group on methane hydrate stability was investigated by monitoring hydrate dissociation at pressures greater than atmospheric pressure in a closed vessel. In particular, the influence of molecular weight and mass concentration of hydroxyethyl cellulose (HEC) was studied with respect to hydrate formation and dissociation. Methane hydrate formation was performed at 2℃ and at a pressure greater than 100 bar. Afterwards, hydrate dissociation was initiated by step heating from -10℃ at a mild pressure of 13 bar to 3℃, 0℃ and 2℃. With respect to the results obtained for methane hydrate formation/dissociation and the amount of gas uptake, we concluded that HEC 90,000 at 5000 ppm is suitable for long-term gas storage and transportation under a mild pressure of 13 bar and at temperatures below the freezing point.     

Artificial Rydberg atom

We analyze bound states of an electron in the field of a positively charged nanoshell. We find that the binding and excitation energies of the system decrease when the radius of the nanoshell increases. We also show that the ground and the first excited states of this system have remarkably the same properties of the highly excited Rydberg states of a hydrogen-like atom, i.e., a high sensitivity to the external perturbations and long radiative lifetimes.