手性配体立体选择性萃取分离扁桃酸对映体

Based on chiral ligand exchange, the distribution behavior of mandelic acid enantiomers in the two-phase system containing copper ion(Ⅱ)(Cu²⁺) and N-n-dedecane-L-hydroxyproline (L), was studied. At different pH, the partition of Cu²⁺ in the two-phase system containing N-n-dedecane-L-hydroxyproline, was investigated. The formation constant of binary cpmplex(Li₂Cu) was obtained by regression. The influence of pH, concentrations of Cu²⁺ and chiral ligand, and solvents on partition coefficients(K) and separation factor(α), was discussed. The experimental results show that Li forms more stable ternary complex with D-mandelic acid than with L- mandelic acid. There is a large influence of pH on K and α. At low pH values (<3.5), formation of binary complexes is thermodynamically unfavourable. K and α are best when pH values are above 3.5 and the molar ratio of chiral ligand to Cu²⁺ is 2∶1. At the same time, solvents influence K and α very much.     

Formation of ring calcium oxalate patterns induced by domains in DPPC Langmuir-Blodgett films

The ring patterns of calcium oxalate crystals were induced by domains in Langmuir-Blodgett （LB） films of dipalmitoylpho- sphatidylcboline （DPPC）. The result was explained by the defects at the ring boundaries of liquid condensed （LC） and liquid expanded （LE） phases of LB film. These boundaries could provide less free energy and much more nucleating sites for COM crystals.     

Ti4+修饰阳离子交换树脂催化制备环已烯

在Ti^4 修饰阳离子交换树脂催化剂上进行了环己醇脱水制备环己烯的反应，考察了催化剂吸附毗啶的FT-IR，证实了该催化剂表面具有Bronsted酸和Lewis酸性住是催化环己烯脱水反应的物质基础，实验结果表明：修饰树脂具有较高的热稳定性，Ti^4 交换容量对阳离子交换树脂的催化活性存在着明显的影响，催化剂对环己醇脱水制环己烯反应的活性高，并得到该反应的优化条件如下：环己醇40g，催化剂5g，反应温度175℃，反应时问60min，在此条件下，环己烯的产率达89％。     

5,10,15-Tris(pentafluorophenyl)corrole as highly selective neutral carrier for a silver ion-sensitive electrode

A new highly selective silver(I) electrode was prepared with a PVC membrane using 5,10,15-tris(pentafluorophenyl)corrole as an electroactive material, 2-nitrophenyl octyl ether (o-NPOE) as a plasticizer and sodium tetraphenylborate (NaTPB) as an additive in the percentage ratio of 3:3:62:32 (corrole:NaTPB:o-NPOE:PVC, w:w). The electrode exhibited linear response with a near Nernstian slope of 54.8 mV/decade within the concentration range of 5.1 × 10⁻⁶ to 1.0 × 10⁻¹ M silver ions, with a working pH range from 4.0 to 8.0, and a fast response time of <30 s. Selectivity coefficients for Ag(I) relative to a number of interfering ions were investigated. The electrode is highly selective for Ag(I) ions over a large number of mono-, bi-, and tri-valent cations. Common interferents like Hg²⁺ and Cd²⁺ show very low interfering effect on the silver assay, which is valuable property of the proposed electrode. Several electroactive materials and solvent mediators have been compared and the experimental conditions were optimized. The sensor was applied to the determination of silver in real ore samples with satisfied results.     

Racemic ofloxacin separation by supported-liquid membrane extraction with two organic phases

As the relation of chirality and activities of drugs is researched deeply, people become to re-alize the clinic importance of chirality. The different enantiomers of a drug can have vastly differ-ent pharmacological activities, pharmacokinetic processes and toxicity[1,2]. The most well-docu- mented example is that of the drug substance thalidomide. Bitter lessons and scientific research promote the interest in single-enantiomer drugs, so the potential of the chiral drug market is enormous[3]. …     

碱土金属掺杂纳米TiO2催化剂的制备与光催化活性的评价

The nanometer TiO₂ were prepared by the hydrolyze-gel method and fellowed by doping alkaline-earth metals (Mg, Ca, Sr, Ba). XRD, SEM, diffuse reflection spectra were used to investigate their characteristices. The result indicates that the average particles size of the TiO₂ is about 80 nm and keep uniformity in distributing. The product was mainly anatase in 300～400 ℃ calcinations, the einstein shift of absorption spectrum was observed after doping the alkaline-earth metals. The best mole percentages of Mg, Ca, Sr and Ba are 0.5%, 1.0%, 1.5%, 1.5% respectively. Under the same reaction conditions, it is more effective to the UV-catalyed degradation reaction that the catalysts containing Mg and Ca were calcined at 300 ℃ for 1h or containing Sr and Ba were calcined at 400 ℃ for 1 h. The photocatalystic activity is considerably depondent on pH and the concentration of the oxidant. Using the sunlight to do the degradation experimental, the result also show that the doping catalysts has higher degradation efficiency than that of pure TiO₂.     

The Use of IR Spectroscopy and Density Functional Theory for Estimating the Relative Concentration of Triglycerides of Oleic and Linoleic Acids in a Mixture of Olive and Sunflower Seed Oils

Optics and Spectroscopy - Infrared spectra of five samples of sunflower seed oil and five samples of cold-pressed olive oil of different brands are recorded in the range of 650–3800...     

Synthesis of N-arylcarbamates with tetrazole fragment and some their derivatives

Reactions of methyl(ethyl) N-(2-cyanophenyl)carbamates with sodium azide in dimethylformamide at 80–90°C in the presence of anhydrous CdCl₂ afforded the corresponding N-arylcarbamates with a 1,2,3,4-tetrazole fragment. The acylation of methyl N-[2-(1H-1,2,3,4-tetrazol-5-yl)phenyl]carbamate with acetic anhydride followed by the condensation of the obtained N-acyl derivative with thiophene-2-carbaldehyde in the KOH methanol solution led to the formation of methyl N-(2-{1-[3-(2-thienyl)-2-propenoyl]-1H-1,2,3,4-tetrazol-5-yl}phenyl)carbamate. The reaction of cyclohexyl N-(4-aminophenyl)carbamate with a triethyl orthoformate and sodium azide in glacial AcOH yielded cyclohexyl N-[4-(1H-1,2,3,4-tetrazol-1-yl)phenyl]carbamate.     

硅凝胶体系中不同结构羧酸钾对草酸钙结晶的影响

采用扫描电子显微镜(SEM)和X射线衍射(XRD)方法研究了硅凝胶体系中不同种类羧酸钾对草酸钙(CaC₂O₄)晶体生长的调控作用. 加入一元醋酸钾(KOAc)只生成一水草酸钙(COM)晶体; 三元柠檬酸钾(K₃Cit)和四元乙二胺四乙酸二钾(K₂EDTA)可诱导二水草酸钙(COD)形成, 且随着其浓度增加, 对COD的诱导能力增加, 而二元酒石酸钾(K₂Tart)同时诱导了COM, COD和三水草酸钙(COT)生成. 随着结晶温度降低, 多元酸钾可以进一步减小COM晶体的比表面积, 增加COD的百分含量, 但K₂Tart诱导COT的能力减弱. 由于诱导COD和COT晶体形成、减小COM的比表面积均有利于防止草酸钙尿石的形成, 因此, 多元羧酸钾可用于草酸钙结石的预防和治疗.