Rhenium(VII) polyhydrides supported by chelating bis -phosphine ligands: DPEphos,xantphos and biphep

Three new rhenium polyhydride complexes, [ReH₇(L₂)], incorporating bidentate organophosphorus ligands (L₂ = DPEphos, xantphos and biphep), were successfully synthesized using the corresponding [ReOCl₃(L₂)] complexes as precursors. The polyhydride complexes were characterized by IR, ¹H and ³¹P NMR, and elemental analysis.     

An unprecedented tetranuclear Zn(ΙΙ) complex with an unsymmetric Salen-type bisoxime ligand: synthesis,crystal structure,and spectral properties

A tetranuclear Zn(ΙΙ) complex, [Zn₄L₂(OAc)₂(CH₃OH)₂] with an unsymmetric Salen-type bisoxime (H₃L?=?6-hydroxy-4′,6′-dibromo-2,2′-[ethylenediyldioxybis(nitrilomethylidyne)]diphenol), has been synthesized and structurally characterized. There are two kinds of coordination geometry (trigonal bipyramidal and square pyramidal) in the Zn(ΙΙ) complex. The molecule has serious distortion probably from the asymmetry. The complex exhibits blue emission with the maximum emission wavelength λ _max?=?423?nm when excited with 340?nm.     

由季戊四醇合成季戊四硫醇的新方法

以季戊四醇为原料,先合成四对甲苯磺酸季戊四醇酯,然后四对甲苯磺酸季戊四醇酯与硫氰酸钾在N,N-二甲基甲酰胺中加热反应,生成了2,3,7,8-四硫螺[4,4]壬烷,2,3,7,8-四硫螺[4,4]壬烷经四氢化铝锂还原、酸化,得到季戊四硫醇.产物结构经熔点、红外光谱、质子核磁共振谱、拉曼光谱鉴定.     

Toroid type high-pressure device: history and prospects

The Toroid type high-pressure device and its predecessor, the Chechevitsa (lentil) type high-pressure device, are known to be used efficiently for the synthesis of new materials in recent decades. It was through the Chechevitsa device the first ultradense modification of silica, ‘stishovite’, was obtained. Both devices were essential for the industrial production of superhard materials in the USSR and other socialist countries. In 1980s, almost half of the world synthetic diamond and c-BN products were manufactured by these devices. However, the application of the Toroid device for examining the structure and physical properties of highly compressed substances has been considerably less appreciated. Meanwhile, the device has some unique features that have made possible 35-years of an extensive investigation of physical properties of substances at pressures up to 150 kbar, including electron transport and thermodynamic properties, elastic characteristics, viscosity, thermo-conductivity and other physical properties. Also, the device has been widely employed for structural X-ray and neutron diffraction studies of many materials. But it is not until recently that the convenience of the Toroid device for physical studies has been fully recognized. Through this recognition, the Toroid type device is today becoming increasingly popular among the researchers in the field of high pressures around the world.     

A pressure vessel for studying gas foaming of thermosetting polymers: sorption,synthesis and processing

We herein report the design of an apparatus for studying the concurrent chemo-physical processes occurring during gas foaming of thermosetting polymers. In particular, to address the recent interest in combining the gas (physical) foaming with the classical (chemical) polyurethane foaming, a novel instrumented pressure vessel was designed for investigating: i) gas sorption under high pressure on the different reactants, kept separate; ii) synthesis under high gas pressure, upon mixing and iii) foaming upon release of the pressure. The design of the new pressure vessel relies on two key features. From the processing side, we make use of a rubber impeller to keep the two reactants separate during gas sorption and to allow for an efficient mixing at the end of the sorption stage. From the analytic side, we utilized a sapphire window beneath the sample holder to use diffuse reflectance near-infrared spectroscopy to measure both the amount of sorbed gas and the reaction kinetics under gas pressure. Preliminary results are reported for the polyol-isocyanate/CO₂ system.     

Synthesis,characterization and energetic properties of novel 1-methyl-1,2,4-triazolium N-aryl/N-pyridinyl ylids

Synthesis, characterization and energetic properties of novel, nitrogen-rich 1-methyl-1,2,4-triazolium N-aryl/N-pyridinyl ylids 3a–m are reported.     

α‐Chlorination of Carboxylic Acids Using Trichloroisocyanuric Acid

Abstract

Carboxylic acids are chlorinated in the α position by heating with trichloroisocyanuric acid after formation of a small amount of the acid chloride using phosphorus trichloride.     

Studies on Azolylacetonitriles: The Reactivity of Thiazole-2-yl,Thiadiazol-2-yl Acetonitriles Toward Electrophilic Reagents

5-Acetyl-2-cyanomethyl-4-methylthiazole, 2-aminothiazole, and 5-N-benzoylamino-1,3,4-thiadiazole-2-yl-acetonitrile react with acetone, and malononitrile derivatives in the presence of sulfur to yield the corresponding thiophene derivatives. Also, 4-furylmethylene-2-phenyl-2-oxazolin-5-ones react with thiophenol, and/or thionaphthol to give the thiolester derivatives in one-pot synthesis. The structures of the products were based on IR, 1 H NMR, and elemental analysis.     

An Efficient and Environment Friendly Procedure for the Synthesis of Arylmethylenemalononitrile Catalyzed by Strong Base Anion‐Exchange Resin in Water

Abstract

Knoevenagel condensation of malononitrile with aromatic aldehydes catalyzed by strong base anion‐exchange resin in water results arylmethylenemalononitrile in 74–98% yield at room temperature.     

Efficient Preparation of γ-Hydroxynitriles via Nitrile Enolate-Epoxide Reactions: Scope and Diastereoselectivity

The nucleophilic opening of epoxides by nitrile enolates using an efficient, convenient protocol is described. The diastereoselectivity of this reaction was explored and found to give syn:anti ratios ranging from 1.1:1.0 to 4.8:1.0.