手性胺醇稀土配合物的合成、荧光性质及其催化芳香酮的不对称氢化反应

合成了三种新的含C₂-对称轴的手性胺醇(PhOHCHCH₂)₂NCH₂C₆H₄R (R＝OCH₃, L₁; R＝CH₃, L₂; R＝Cl, L₃), 将其与无水氯化稀土LnCl₃•4THF (Ln＝La, Sm, Gd)反应生成了九个新的胺醇类稀土配合物LLnCl•2THF (L＝L₁, L₂, L₃; Ln＝La, Sm, Gd). 用元素分析、热重分析、红外和紫外光谱等手段对它们进行了表征. 荧光光谱显示一些配合物具有荧光性能. 原位催化芳香酮的不对称氢化反应表明: L₁/SmCl₃•4THF体系催化苯乙酮不对称氢化反应的转化率达71%, 相应的对映体过量值达32%.     

Determination of alcohol polyether average molar oligomer value/distribution via supercritical fluid chromatography coupled with UV and MS detection

Supercritical fluid chromatography (SFC) was used for the analysis of ethoxylated and propoxylated surfactants. Samples were derivatized to phenylated silyl ethers with a disilazane-chlorosilane mixture. Addition of a phenyl group to the surfactant allowed UV-absorbance detection of each oligomer. Acetonitrile and methanol were evaluated as mobile phase modifiers. Better peak shape was realized with methanol-modified CO2 on an octadecyl silica bonded phase than with acetonitrile-modified CO2. Peak assignments were made via SFC coupled with electrospray ionization-mass spectrometry (ESI-MS) in the positive ion mode. A sulfonamide-embedded alkyl stationary phase was also evaluated for separation of the derivatized samples. SFC-UV and SFC-ESI-MS data were jointly used for calculation of average molar oligomer values which were then compared to values calculated from 1H NMR data of non-derivatized samples. The derivatization or separation method using the sulfonamide embedded phase required no preliminary cleanup and yielded reproducible oligomer values that were consistent with those of the manufacturer's nominal values.     

Sulfur hexafluoride as a mobile phase for supercritical fluid chromatography

Summary The capabilities of sulfur hexafluoride as a mobile phase for supercritical-fluid chromatography are investigated. An evaluation of its overall utility on the basis of separations of standard aromatic hydrocarbon odel mixtures performed on a variety of bonded-phase, packed columns with UV detection is presented. The dependence of separation performance upon operational parameters is also examined. A comparative evaluation of the chroamtographic properties of supercitrical sulfur hexafluoride and those of supercritical carbon dioxide is developed from these separations under corresponding supercritical state conditions.     

γ－芳基取代烯丙醇菊酯的合成及杀虫活性

γ－芳基取代烯丙醇菊酯的合成及杀虫活性陈亚娟，黄润秋，马军安（南开大学元素有机化学研究所，天津，３０００７１）关键词γ－芳基取代烯丙醇，拟除虫菊酯，杀虫活性第一个人工合成除虫菊酯烯丙菊酯保留了天然除虫菊酯醇部分的环戊烯醇酮结构，至今仍广泛用作卫生杀虫...     

Refining adsorption parameters of n-butyl alcohol at the interface of mercury electrode with aqueous NaF and Na2SO4 solutions by correcting the adsorbate concentration

As an adjunct to the regression analysis of differential capacitance curves, which allows refining the adsorption parameters, a program, which takes into account possible errors in volume concentrations of organic substances, is developed. Using this procedure, the earlier data on the differential capacitance of a mercury electrode in aqueous solutions of normal butanol (1-BuOH) containing either 0.1 M NaF or 0.05 and 0.5 M Na₂SO₄ as the supporting electrolyte are analyzed. This allows obtaining the most accurate values of adsorption parameters for the systems mentioned above within the framework of the model of two parallel capacitors and the Frumkin isotherm. It is shown that, when a linear dependence of the intermolecular interaction parameter on the electrode potential is taken into account, the standard deviation of experimental capacitance values from those calculated using the mentioned model is 6.8–8.8%, which points to very high accuracy of this phenomenological model.     

Analysis to obtain precise density fluctuation of supercritical fluids by small-angle X-ray scattering

A procedure of analysis for small-angle X-ray scattering (SAXS) data has been established to obtain density fluctuation of supercritical fluids near the critical point. It is indispensable for the certain analysis to utilize both of high-quality SAXS data measured under stable thermodynamic condition and accurate P–ρ–T data in supercritical region. As a standard example, SAXS measurements have been performed for supercritical CO₂, which is a suitable sample satisfying the condition for both experiment and analysis. The measurements were carried out along four isothermal conditions at reduced temperature of T_r = T/T_c = 1.020, 1.022, 1.043 and 1.064. Comparing the experimental density fluctuation with calculated one from the most reliable equation of state, the differences are within 8% at most.     

HMS和NaY固载酒石酸钛配合物的研究

利用化学键合和“瓶中造船”方法,成功地将酒石酸钛配合物接枝到HMS(heragonal mesoporous silicas)上或包络合于微孔NaY内.FT-IR表征表明酒石酸钛在HMS上是通过与载体表面羟基发生交换作用而被固载的;在NaY载体上则是通过包络合被封装在载体的超笼内.UV-Vis可见漫反射表征表明两类固载型催化剂有着相似的钛配位环境.在催化肉桂醇环氧化反应中,HMS键合型催化剂的反应转化率比NaY包络型催化剂的高;但后者在环氧化选择性上要高于前者.回收样品的重复使用实验结果表明,两类固载型催化剂在重复使用过程中均存在不同程度的失活.     

Integrated production of ethanol fuel and protein from Coastal Bermudagrass

The herbaceous crops that may provide fermentable carbohydrates for production of fuels and chemicals also contain 10–20% protein. Protein coproduction with biomass-derived fuels and chemicals has important advantages: (1) food and fuel production can be integrated, and (2) protein is a high-value product that may significantly improve overall process economics. We report the results of an integrated approach to producing protein and fermentable sugars from one herbaceous species, Coastal Bermudagrass (CBG). The ammonia fiber explosion (AFEX) process makes possible over 90% conversion of cellulose and hemicellulose to simple sugars (about 650 mg reducing sugars/g dry CBG) at 5 IU cellulase/g vs < 20% conversion for untreated CBG. The AFEX treatment also improves protein extraction from CBG; over 80% protein recovery is possible from AFEX-treated CBG vs about 30% recovery from untreated CBG.     

High-performances membranes for pervaporation I. Poly(vinyl alcohol)–poly(N-vinyl pyrrolidone) blends

Dense membranes were prepared from poly(vinyl alcohol)–poly(N-vinyl pyrrolidone) (PVA–PVP) blends of different compositions and studied in swelling and dehydration by pervaporation of three organic solvents contaminated by 5 wt% water. The swelling generally increases with the PVP content. No extraction occurs in water–tetrahydrofuran (THF) and water–methyl ethyl ketone (MEK) mixtures. In ethanol containing 10 wt% of water, there is no extraction for blends containing less than 40 wt% PVP and an increasing extraction beyond this PVP content. The pervaporation flux of the water–ethanol mixture increases drastically at the same threshold whereas the water permselectivity falls to a low level. The values of the diffusion and permeability coefficients determined from transient permeation of the test water–ethanol mixture exhibit a similar sudden increase at the same PVP content threshold. This singular behavior of the blend membranes is interpreted by a strong affinity of the PVP component to ethanol, combined with a disappearance of crystallites in the blend at this threshold. Consequently the amorphous membrane can swell freely according to the affinity of the PVP component, leading to the observed behavior.     

超临界流体萃取仪器的研制

本文报道了以国产原配件为基础，成功地研制了分析规模的超临界流体萃取仪器、并对仪器性能进行了全面考察，仪器性能稳定，重现性良好（ＲＳＤ＜３．１％），定量线性关系可靠，可满足定量萃取的要求。