高效液相色谱直接分离μ-FcCCHCoW(CO)5(CpCOOC2H5)簇合物对映体

将三（苯基氨基甲酸）支链淀粉酯涂敷在硅胶上制成了手性固定相．将支链淀粉与过量的苯异氰酸酯在吡啶中反应得到的苯基氨基甲酸酯溶解并涂敷在用３－氨基丙基三乙氧基硅烷处理过的硅胶上，涂敷量为０．４５／２．５５（重量比）．用此手性固定相拆分了外消旋的簇合物μ－ＦｃＣＣＨＣｏＷ（ＣＯ）５（ＣｐＣＯＯＣ２Ｈ５）．拆分在室温下进行，洗脱液为甲醇，流速为０．５ｍＬ／ｍｉｎ．     

OXIDATIVE COUPLING OF METHANE OVER Mn_2O_3-Na_2WO_4/SiO_2 CATALYST Ⅰ.CHARACTERIZATION OF ACTIVE SITES ON THE CATALYST

EPR and Raman spectroscopy have been used to characterize the catalyst. F-centers with EPR parameter of g=2. 0046 form when gas phase oxygen is admitted onto the catalyst reduced with methane at 800℃- Molecular oxygen plays an induced role in the electron transfer from W4 to the oxygen ion vacancy which is produced by methane reduction. Raman spectra give the further evidence for the production of lattice oxygen from molecular oxygen.     

SYNTHESIS AND EVALUATION OF A NEW PHOTOSTABILIZER—2, 2, 6, 6-TETRAMETHYL-4-PIPERIDINYL SALICYLATE FOR POLYMERS

A new photostabilizer--2,2,6,6-tetramethyl-4-piperidinylsalicylate (TMPS) has been syn-thesized by ester-exchange reaction between 2,2, 6, 6-tetramethyl-4-piperidinol and methylsalicylate.The photostabilizing effect of TMPS and Tinuvin 770, PDS on the photodegradation of cis-1,4-polybutadiene has been investigated for comparison. The results observed show that the mosteffective stabilizer of the three is TMPS. The reason of the good photostabilizing effect of TMPSwas discussed by fluorescence spectra.     

Pd（OAc）2／FePc催化环己烯氧化合成环己酮的研究

考察了几种Ｆｅ－大环配合物与Ｐｄ（ＯＡｃ）２组成的双组分催化体系，在乙腈酸性水溶液中环己烯经合成环己酮的催化活性，实验结果表明，其中以酞菁失（ＦｅＰｃ）与Ｐｄ（ＯＡｃ）２组成的催化体系活性最高，而ＦｅＴＰＰＣｌ与Ｐｄ（ＯＡｃ）２催化体系，虽然催化活性较高，但催化剂的稳定性较低，各种因素对Ｐｄ（ＯＡｃ）２／ＦｅＰｃ催化活催化影响的研究结果指出，在无水和酸存在的非水溶液中，Ｐｄ（ＯＡｃ）２／ＦｅＰｃ对     

亚磺化脱卤试剂在有机合成中的应用

本文综述了亚磺化脱卤试剂在有机合成中的应用。特别是氟烷基化反应中的应用。     

A novel route to nanosized molybdenum boride and carbide and/or metallic molybdenum by thermo-synthesis method from MoO3, KBH4, and CCl4

Nanosized molybdenum boride and carbide were synthesized from MoO₃, KBH₄, and CCl₄ by thermo-synthesis method at lower temperature. The relative content of Mo, Mo₂C, and molybdenum boride in the product was decided by the molar ratio between MoO₃, KBH₄, and CCl₄. Increasing the molar ratio of CCl₄ to MoO₃ was favorable to the production of Mo₂C. Increasing the molar ratio of KBH₄ to MoO₃ was favorable to the production of molybdenum boride. By carefully adjusting the reaction conditions and annealing in Ar at 900°C, a single phase of MoB could be obtained.     

端视ICP－AES系统分析性能研究──Ⅰ．在稀土分析中的应用

本工作通过比较端视与侧视ＩＣＰ的分析性能，研究了端视ＩＣＰ系统对稀土元素的分析特性。高频发生器输出功率与载气流量对端视与侧视ＩＣＰ激发特性的影响没有明显差异，取光方式的不同是二者分析性能差异的根本原因。端视ＩＣＰ由于取光时避开了产生连续背景的环形热区和截取了整个中心通道的光谱，其背景减小，谱线强度增强，获得较好的测定下限。对１４种稀土元素测定下限的比较表明：端视ＩＣＰ比铡视ＩＣＰ下降１０－３０倍。     

DABCO-catalyzed reaction of alpha-halo carbonyl compounds with dimethyl acetylenedicarboxylate: a novel method for the preparation of polysubstituted furans and highly functionalized 2H-pyrans

[Chemical reaction: see text] Polysubstituted furans and highly functionalized 2H-pyrans were prepared in good yields by DABCO-catalyzed reactions of alpha-halo carbonyl compounds with dimethyl acetylenedicarboxylate (DMAD) at room temperature.     

新型醋酸乙烯酯／二乙烯苯共聚物的研究（Ⅱ）──醇解物的制备、结构及其性能

新型醋酸乙烯酯／二乙烯苯共聚物的研究（Ⅱ）──醇解物的制备、结构及其性能吴向东，郭贤权，何炳林（南开大学高分子化学研究所，天津，３０００７１）关键词皂化反应，醇解物，芳香族氨基酸，孔结构参数，吸附性能氨基酸失衡是指肝性脑病患者血液中芳香族氨基酸的浓度...     

Electronic effects steer the mechanism of asymmetric hydrogenations of unfunctionalized aryl-substituted alkenes

Density functional theory (PBE and B3LYP) was used to study asymmetric hydrogenations of alkenes catalyzed by an iridium imidazolylidine oxazoline complex. The calculation predicts that the alkene preferentially coordinates to the site trans to the carbene. The coordinated alkene then reacts first with the H2 ligand, then with the hydride to form alkane. Finally, the alkane is released by equilibrating with extrinsic H2 and alkene. Enantioface selectivities for hydrogenations of trisubstituted alkenes seem to be driven primarily by steric interactions with the adamantyl part of the ligand; only the smallest substituents can adopt a site close to it. Application of this theoretical model leads to correct predictions regarding the experimentally observed sense and magnitude of the enantioselectivities.