甲基丙烯酸三苯墓甲酯和甲基丙烯酸酯类的共聚物在溶液中的螺旋诱导和解旋作用

甲基丙烯酸三苯墓甲酯和甲基丙烯酸酯类的共聚物在溶液中的螺旋诱导和解旋作用陈传福，刘卫宏，陈永明，任长玉，习复（中国科学院化学研究所北京１０００８０）关键词甲基丙烯酸三苯基甲酯，甲基丙烯酸甲酯，光学活性，螺旋诱导，解旋在手性阴离子复合引发剂存在下，甲基...     

Surface-enhanced Raman scattering studies on the adsorption of p-nitrobenzoic acid at Au electrode under different potential with ultraviolet excitation

The potential-dependent surface-enhanced Raman spectrum of adsorbed p-nitrobenzoic acid (PNBA) on the roughened Au electrode has been obtained by using ultraviolet (UV) excitation at 325 nm. The surface-enhanced Raman spectra of PNBA intensely changed when the voltage was in the rang of negative value, and the electrode potential at which the resonance (potential of maximum intensity) occurs varied when the vibrational mode changes, indicating that the PNBA molecules were chemisorbed on the roughened Au surface. The charge transfer (CT) mechanism could probably explain the experiment results in the present work.     

变温红外光谱研究多嵌段聚氨脂脲的微相分离行为

用傅里叶变换红外光谱方法研究了热处理对由聚环氧丙烷聚醚多元醇、３．５－二乙基甲苯二胺和４，４－二苯基甲烷二异氰酸酯组成的多嵌段聚氨酯脲（ＳＰＵＵ）的微相分离行为的影响．从室温逐步升温到３１０℃的过程中，氨基甲酸酯键（ＵＴ）之间形成的氢键大量解离，而脲键（ＵＡ）之间形成的、具有平面状双分叉结构的氢键在１３０～２００℃范围却大量生成；从３１０℃缓慢冷却到室温后，部分游离的ＵＴ重新形成氢键，而硬段之间形成的ＵＡ氢键的含量又有所增加．结果表明：高温热处理可以有效地提高ＳＰＵＵ的微相分离程度．     

Spectroscopic studies on 2,3,4,5-tetraphenylpyrylium salts with and without silver (I)-bridged structures

Two novel phenylated pyrylium compounds, silver (I)-bridged 2,3,4,5-tetraphenylpyrylium perchlorate (P1) and its silver (I)-free pyrylium ligand (P2) were prepared from 1,2,3,4-tetraphenylcyclopentadiene to examine their spectroscopic behaviors. The UV/vis absorption and fluorescent emission spectra of P1 and P2, measured in three solvents (acetonitrile, dichloromethane and toluene), reveal that the photophysical behaviors are closely related to silver (I) fragment, and strongly dependent on solvent polarity. In polar acetonitrile, P1 displays longer absorption wavelength and much lower fluorescent emission intensity than P2, although they exhibit much similarity in shape. In contrast, in nonpolar toluene, while P2 shows an apparent absorption band at 338 nm, P1 displays a tail-like line without absorption band observed. All the spectra obtained indicate a better coplanarity and a stronger intra-molecular charge transfer in P1 due to the effect of silver (I) fragment. Additionally, the 1H NMR spectra of P1 and P2, which were recorded under the same conditions, indicate that the silver (I) fragment reinforces pyrylium ring's capacity to localize the formal positive charge within the heterocyclic ring.     

PREPARATION OF CUO/γ-Al2O3 CATALYSTS FOR CATALYTIC COMBUSTION VOCS VIA PLASMA

CuO/γ-Al2O3 catalysts were prepared by plasma treatment and conventional impregnation methods. The catalytic combustion of two kinds of volatile organic compounds (VOCs), toluene and benzene, were carried out over these CuO/γ-Al2O3 catalysts. The surface properties of these catalysts were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The experimental results showed that in catalytic combustion the activity of the CuO/γ-Al2O3 catalyst prepared via plasma was much higher than that of the CuO/γ-Al2O3 catalyst prepared by conventional impregnation method. XRD results showed that an enhanced dispersion had been achieved with the plasma treatment. SEM results indicated that the size became much smaller and the surface became more uniform with the plasma treatment.     

SYNTHESIS AND CHARACTERIZATION OF A NEW POLYSILOXANE CONTAINING N,N’-BIS(DIPHENYLSILYL)TETRAPHENYLCYCLODISILAZANE

A new kind of polysiloxane containing N,N'-bis(diphenylsilyl)tetraphenylcyclodisilazane was prepared by anionicnon-equilibrium polymerization with a "seed solution" as initiator. The monomer, N,N'-bis(hydroxydiphenylsilyl)-tetraphenyl-cyclodisilazane (BHPTPC), was synthesized via the hydrolysis of N,N'-bis(chlorodiphenylsilyl)tetraphenyl-cyclodisilazane (BCPTPC). A new method for the preparation of BCPTPC is also reported here with high yield and simplermanipulation. The synthesized polysiloxane containing N,N'-bis(diphenylsilyl)tetraphenylcyclodisilazane was characterized by ~1H-NMR, ~(29)Si-NMR, gel permeation chromatography (GPC) and intrinsic viscosity.     

从核磁共振氢谱推导的重质油氢碳原子摩尔比计算式

通过对炼油厂的催化油浆、重催油浆和催化重焦蜡油核磁共振氢谱中质子归属和重质油结构的假设，推导出计算这3种重质油的氢碳原子摩尔比计算式；结果表明，氢碳原子摩尔比的计算值与实测值非常接近，平均误差仅为3．1％。     

Cyclopalladated ferrocenylimine: a highly effective catalyst for the borylation/suzuki coupling reaction

The cyclopalladated ferrocenylimine was an efficient catalyst for the borylation/Suzuki coupling reaction. The catalytic loading for the reaction containing bromoarenes was 1 mol %. When iodobenzene was used, the catalytic loading was as low as 0.1 mol %. Furthermore, the cyclopalladated ferrocenylimine also exhibited excellent catalytic power in the case of substrates containing electron-donating substituents, with yields reaching 93% or higher.     

Separation of ephedrine stereoisomers by molecularly imprinted polymers--influence of synthetic conditions and mobile phase compositions on the chromatographic performance

Separation of ephedrine stereoisomers by molecularly imprinted polymers was performed to study the factors that affect the selectivity and column efficiency. The polymer synthesized with pentaerythritol triacrylate as the cross-linker and chloroform as the porogen was found to have the best overall separation performance. Investigation of the recognition mechanism by NMR and chromatographic analysis revealed that the major binding forces between the polymer stationary phase and ephedrine are the ionic and hydrogen bonding interactions. Studies of the influence of mobile phase compositions on the HPLC analysis have shown that a methanol-aqueous buffer was the suitable mobile phase for the separation in which pH, ionic strength and water content can be adjusted to optimize the chromatographic analysis.     

聚（甲基丙烯酸甲酯—二甲基二烯丙基氯化铵）的合成及表征

以水和乙醇作混合溶剂，用逐步滴加甲基丙烯酸甲酯的方法，通过自由基聚合，由溶解性和共聚活性差异较大的两种单体ＭＭＡ和二甲基二烯丙基氯化铵合成了新型含阳离子共聚物聚，并用ＩＲ和＾１Ｈ－ＮＭＲ进行了分析表征。该共聚物溶于丙酮和水组成的二元溶剂，并与Ｐ（ＭＭＡ－ＭＡＡ）有较强的分子复合能力。