Generation of Organozinc Reagents by Nickel Diazadiene Complex Catalyzed Zinc Insertion into Aryl Sulfonates

The generation of arylzinc reagents (ArZnX) by direct insertion of zinc into the C−X bond of ArX electrophiles has typically been restricted to iodides and bromides. The insertions of zinc dust into the C−O bonds of various aryl sulfonates (tosylates, mesylates, triflates, sulfamates), or into the C−X bonds of other moderate electrophiles (X=Cl, SMe) are catalyzed by a simple NiCl₂–1,4-diazadiene catalyst system, in which 1,4-diazadiene (DAD) stands for diacetyl diimines, phenanthroline, bipyridine and related ligands. Catalytic zincation in DMF or NMP solution at room temperature now provides arylzinc sulfonates, which undergo typical catalytic cross-coupling or electrophilic substitution reactions.     

Timing properties and pulse shape discrimination of LAB-based liquid scintillator

Linear Alkyl Benzene (LAB) is a promising liquid scintillator solvent in neutrino experiments because it has many appealing properties. The timing properties of LAB-based liquid scintillator have been studied through ultraviolet and ionization excitation in this study. The decay time of LAB, PPO and bis-MSB is found to be 48.6 ns, 1.55 ns and 1.5 ns, respectively. A model can describe the absorption and re-emission process between PPO and bis-MSB perfectly. The energy transfer time between LAB and PPO with different concentrations can be obtained via another model. We also show that the LAB-based liquid scintillator has good (n, γ) and (α, γ) discrimination power.     

Electrophilic Addition Reaction of Ethene with Hydrogen Chloride on Cold Molecular Films: Evidence of Ethyl Cationic Intermediate

We studied the initial‐stage mechanism of the electrophilic addition reaction of ethene with HCl by examining the interactions between ethene and HCl on water‐ice and frozen molecular films at temperatures of 80–140 K. Cs⁺ reactive ion scattering (RIS) and low‐energy sputtering (LES) techniques were used to probe the reaction intermediates that were kinetically trapped on the surface, in conjunction with temperature‐programmed desorption (TPD) mass spectrometry to monitor the desorbing species. The reaction initially produced the π complex of HCl and ethene at temperatures below about 93 K and an “ethyl cationic species” at temperatures below about 100 K. The ethyl cationic species was formed via direct proton transfer from the HCl molecule to ethene with the assistance of water solvation, rather than via the interaction of hydronium ions and ethene. At high temperatures, this species dissociated into ethene and hydronium and chloride ions. The reaction did not, however, complete the final transition state on the ice surface to produce ethyl chloride. The observation gives evidence that the electrophilic addition reaction of ethene occurs through an ethyl‐like intermediate with an ionic character.     

The Interfacial Tension and Alkane Carbon Number (nmin) of Alkyl Benzene Sulfonates in Relation to Enhanced Oil Recovery. Part I: Effect of Surfactant Molecular Weight/Temperature and Electrolyte on nmin

Twelve anionic monoisomeric surfactants based on the alkyl benzene sulfonic acid were prepared. In two sets of experiments, the (n_min) values were determined at 28 and 70°C for them. The n-hydrocarbon scans (n-C₅ to n-C₁₈) against the interfacial tension were used to determine the (n_min) values. The factors affecting (n_min) such as; molecular weight, branching of side chain, temperature and electrolyte addition were investigated. From the obtained results, it was found that the surfactants which has the highest molecular (8φ C₁₅ ABS) gave (n_min) equal 8, so it can be used in the enhanced oil recovery(EOR) without additives (the suitable (n_min) for EOR between 7-9). Otherwise, the lowest molecular weight surfactant (7φ C₁₃ ABS) gave (n_min) equal 5 without addition of alcohols or electrolyte. This case needs some additives to adjust the (n_min) in the range of 7 to 9. By investigation the factors affecting (n_min), it was found that the side chain of alkyl benzene shifted the (n_min) to the highest values. The increasing of temperature decreased the (n_min) values. Also, it was found that the (n_min) increased to high value by adding the electrolytes and alcohols. The mixture between surfactants with and without side chain shifted the (n_min) to the highest value. Using these parameters, the alkane carbon number (n_min) can be used to select the suitable solvent during the preparation of emulsion to get the minimum interfacial tension at which the maximum emulsion stability should be obtained and also to select the surfactant for EOR.     

Study on Foaming Properties and Dynamic Surface Tension of Sodium Branched-alkyl Benzene Sulfonates

Foaming properties and the dynamic surface tension (DST) were carried out with aqueous solutions of sodium branched-alkyl benzene sulfonates to elucidate the relationship between foaming properties and surfactant structures. The parameters of the DST (t*, n, R _1/2 ) are correlated with the foaming ability for alkyl benzene sulfonates with benzene ring substituting at positions 2, 4, and 8 of hexadecane. The parameters of the DST (t*, n, R _1/2 ) are correlated with the foaming ability of the same surfactant solutions. The results indicated that the molecular diffusion in the solution, adsorption, and arrangement at the air/water interface were changed with different molecular structures: changing the substituted position of benzene ring from 2 to 8 of hexadecane, the value of t* and n decrease, and the value of R _1/2 increases, which lead to the high dynamic surface activity and high foam volume. The foam stability is correlated with the high surface dilational elasticity and the strength of surface monolayer: changing the substituted position of benzene ring from 2 to 8 of hexadecane, the branched-alkyl chain becomes more flexible, which is characterized by densely packed adsorbed molecules and high film elasticity of the adsorption film. Therefore, the foam stability increases.     

Conformational studies of intermolecular hydorgen bonding through induced crystal G phase in nBA:7HB

This paper exploits the physical investigation on liquid crystal complexes obtained by self-organisation of p-n-alkyl benzoic acid (nBA) mesogens with non-mesogenic materials heptyl p-hydroxy benzoate (7HB). Intermolecular interactions of the molecules result the hydrogen bond between the proton donor (COOH) of nBA and proton acceptor (OH) of 7HB. The formation of hydrogen bond is attributed to the quenching of the nematic phase and inducement of crystal G phase in liquid crystal complex. A comparative study of phase abundance is presented with respect to the pure nBAs and other hydrogen bonded liquid crystal complexes of nBAs. Thermal and phase behaviour of the complexes are determined by polarising optical microscope (POM), differential scanning calorimetry (DSC) and image moments approach. Intermolecular interactions which result the hydrogen bond in complexes are investigated using Fourier transform infrared (FTIR) spectroscopy. Molecular structure of the liquid crystal complexes in the solid phase was elucidated using powder X-ray diffraction and proton nuclear magnetic resonance (¹HNMR).     

苄基淀粉醚与烷基多糖苷复配制备氰氟草酯水乳剂

以苄基淀粉醚与烷基多糖苷复配为乳化剂,油酸甲酯为溶剂,采用浓缩乳化法制备了高度稳定的10%氰氟草酯水乳剂。分析了苄基淀粉醚的红外和紫外特征图谱。采用正交试验设计,通过测定乳滴粒径分布,结合乳液外观,研究了乳化方法、预处理液中苄基淀粉醚与烷基多糖苷质量分数、转速和剪切时间等工艺条件对乳液稳定性的影响。结果表明,苄基淀粉醚与原淀粉相比,在红外、紫外光照射下出现了苯甲基的特征吸收峰。以苄基淀粉醚与烷基多糖苷质量比3∶2复配为乳化剂、质量分数9%油酸甲酯为溶剂制备的10%氰氟草酯水乳剂,乳滴平均粒径在1.02μm左右,且经(54±2)℃密封14 d加速试验和常温储存6个月后,平均粒径仅增长0.1~0.6μm,析水率为2.7%,均优于用常规乳化剂和溶剂制备的10%氰氟草酯水乳剂。因此,苄基淀粉醚与烷基多糖苷以及油酸甲酯可作为备选乳化剂和溶剂,用于环境相容性好的农药剂型加工。     

REDUCTION OF TERMINAL ORGANYLCHALCOGENO PHOSPHONATES AS A WAY TO PREPARE PRIMARY ORGANYLCHALCOGENO PHOSPHINES

2-Organylseleno(telluro)ethyl phosphines and 4-organylthio(seleno (telluro))butyl phosphines were prepared by reduction of diethyl 2-organylseleno(telluro)ethyl phosphonates and diethyl 4-organylthio(seleno(telluro)) butyl phosphonates with lithium aluminium hydride in diethyl ether. ¹H and ³¹P NMR spectra as well as mass spectra of the resulting phosphines were considered. Their stability in regard to the oxidation by oxygen was discussed.     

一种SO2固定及用于制备BaSO3或BaSO4的方法

在常温常压下,由乙二胺（EDA）和乙二醇及其衍生物（EGs）组成的混合体系可捕集SO₂并转化为一种SO₂储集材料（SO₂SM）。EDA+EGs体系呈现了强的捕集性能（0.364~0.662 g_SO2·g_absorbent^-1）。FTIR,XPS和XRD结果确证了SO₂SM为一种烷基亚硫酸盐。以EG-SO₂SM为原料制备具有多种形貌的BaSO₃或BaSO₄,在此过程中,EG-SO₂SM不仅提供了原材料,而且可以释放EDA和EG用作表面活性剂,调控晶体的结晶化过程。