钴的二苯甲酰甲烷配合物：晶体结构及其轴向置换反应

Cobalt(Ⅱ) can form complexes with Hdbm in different environments. Hdbm reacted with cobalt nitrate to give complex 1 [Co(dbm)₂·2H₂O]. When complex 1 reacted with pyridine， α-stilbazole or 4，4′-bipyridine respectively， complex 2 [Co(DBM)₂Py₂] (Py=pyridine)， 3 [Co(DBM)₂Sbz₂] (Sbz=α-stilbazole) or 4 [Co(DBM)₂BPy]_n was obtained in turn through metathetical reaction. The coordination modes are octahedral polyhedrons. In the crystal structures， the two dbms take the plane position and two other donor molecules take the axial position. CCDC： 196070 for complex 2; 186859 for complex 3.     

Determination of Tetracyclines in Honey Using Liquid Chromatography with Ultraviolet Absorbance Detection and Residue Confirmation by Mass Spectrometry

A determination method has been optimized and validated for the simultaneous analysis of tetracycline （TC）, oxytetracycline （OTC）, chlortetracycline （CTC） and doxycycline （DC） in honey. Tetracyclines （TCs） were removed from honey samples by chelation with metal ions bound to small Chelating Sepharose Fast Flow columns and eluted with Na2EDTA-Mcllvaine pH 4.0 buffers. Extracts were further cleaned up by Oasis HLB solid-phase extraction （SPE）, while other solid-phase extraction cartridges were compared. Chromatographic separation was achieved using a polar end-capped C 18 column with an isocratic mobile phase consisting of oxalic acid, acetonitrile and methanol. LC with ultraviolet absorbance at 355 nm resulted in the quantitation of all four tetracycline residues from honey samples fortified at 15, 50, and 100 ng/g, with liner ranges for tetracyclines of 0.05 to 2 μg/mL. Mean recoveries for tetracyclines were greater than 50% with R.S.D. values less than 10% （n= 18）. Detection limits of 5, 5, 10, 10 ng/g for oxytetracycline, tetracycline, chlortetracycline and doxycycline, respectively and quantitation limits of 15 ng/g for all the four tetracyclines were determined. Direct confirmation of the four residues in honey （2-50 ng/g） was realized by liquid chromatography-tandem mass spectrometry （LC/MS/MS）. The linear ranges of tetracyclines determined by LC/MS/MS were between 5 to 300 ng/mL, with the linear correlation coefficient r〉 0.995. The limits of detection of 1 to 2 ng/g were obtained for the analysis of the TCs in honey.     

聚对苯乙烯磺酸钠添加剂的分子量对水煤浆浆体性质的影响

选用了变质程度不同的八种煤和三种不同分子量的聚对苯乙烯磺酸钠（PSS）添加剂，详细考查了该添加剂的分子量对水煤浆浆体性质的影响。结果发现，在考查PSS相对分子量的范围内（质均分子量为5.34×104～33.39×104），八种煤的水煤浆成浆性随着分子量的增大而增加，水煤浆成浆性与PSS添加剂的平均分子量的关系可归因于添加剂在煤粒上的吸附，分子量小的PSS在煤粒上的吸附量大于分子量大的PSS；PSS分子量的增加有利于水煤浆的流变性由胀性向假塑性转变；PSS分子量的增加使水煤浆的静态稳定性得到显著的改善。     

STUDY ON POLYSULFONE-POLYESTER BLOCK COPOLYMERS

Synthesis and characterization of a series of Polysulfone (PSF)-Polyester (PEs) block copolymers were studied.The degree of randomness (B) of these block eopolymers was calculated from the intensities of their proton signals in ~1H NMR spectra and lies in the region of 0相似文献   

Spectrophotometric and Voltammetric Studies on the Interaction of Heparin with Phenosafranine

The interaction of phenosafranine （PSF） with a glycosaminoglycans of heparin （Hep） in aqueous solution has been characterized by UV-Vis absorption spectrophotometry and cyclic voltammetry in pH 1.5 Britton-Robinson （B-R） buffer solution. The addition of Hep caused decrease of the absorbance of PSF at 532 nm and the redox peak current of PSF. The study showed that an supramolecular complex of PSF-Hep was formed because of the electrostatic attraction of negatively charged Hep with the positively charged PSF, which resulted in the decrease of the equilibrium concentration of PSF in solutions, and the decrease of the absorbance or the peak current of PSF. The stoichiometry of the Hep/PSF complex was further calculated by voltammetric data with the result of 1：1 complex.     

FTIR及Py-GC/MS定性分析高聚物单体

红外光谱反应出的是特征化学基团的振动 ,对于高聚物的具体单体组成分析 ,只能借助于紫外光谱、核磁共振及质谱进行综合判断才能得到圆满的鉴定结果[1,2 ] 。本工作针对在红外光谱仪不能分辨的情况下通过气相色谱 质谱联用技术进行综合分析鉴定 ,结果可为其它高聚物分析研究提供实验依据。1　实验1 1　仪器及试验条件未知高聚物试样为白色颗粒状 (晨光化工二厂 )。ＳＹＳＴＥＭ2 0 0 0ＦＴＩＲ ,ＰＥ公司造ＩＲ谱仪 ;ＣＤＳ2 0 0 0铂金丝裂解器 ,裂解室温度 2 5 0℃ ,裂解温度 6 0 0℃ ,升温速率 1 40℃ ｍｓ;ＨＰ6 890型 ,Ｃｏｍｐｏｎｄ…     

Solution Structure and Behavior of Benzophenone-based Achiral Bisphosphine Ligands in Noyori-Type Ru（Ⅱ）-Catalysts

We herein report on solution structural studies of Ru^Ⅱ catalysts （3a, 9） composed of achiral bisphosphine ligands （4, 8） and the enantiopure 1,2-diphenylethylenediamine （DPEN）. Complete chiral induction from enantiopure （R,R）-DPEN to achiral bisphosphine ligand 3a was observed in solution, with the complex adopting a single, stable and non-fluxional （even at 70 ℃） configuration. The coordination of the C=O moiety in 4 to the cationic Run center is considered to be of key importance in providing the higher thermodynamic and kinetic rotation barrier for the flexible bisphosphine ligand in the complex. The obtained enantioselectivity （91% enantiomeric excess） and sense of chiral induction in the hydrogenation of acetophenone were found to be solely dependent on the chirality of the 1,2-diamine. Consistent with the hydrogenation product, the （R,R）-DPEN induces a M-conformation （fight-handed） chirality for flexible phosphine ligand 4 in the complex, resulting in a 2,2-configuration about the Ru^Ⅱ center.     

吹扫-捕集气相色谱法测定水中挥发性卤代烃

研究建立了吹扫 捕集法富集样品 ,利用HP 1大口径厚液膜通用型熔融石英毛细管柱 (30m× 0 .5 3mm×2 .6 5 μm) ,ECD检测器 ,测定水中 10种挥发性卤代烃的方法 ,确定了最佳吹扫 捕集条件 .结果表明 :水样体积为 5mL时 ,标准偏差在 0 .0 2～ 0 .0 7μg L之间 ,变异系数在 1.0 9%～ 3.2 8%之间 ,加标回收率为 94.0 %～ 10 7%之间 ,10种物质的检出限在 0 .0 7～ 0 .19μg L之间     

钒氧阴离子团簇与小分子碳氢化合物反应的实验和理论研究

为了在分子层次上揭示相关催化反应的机理, 人们对过渡金属氧化物团簇与碳氢化合物分子反应进行了大量研究. 相比于过渡金属氧化物团簇阳离子, 阴离子对一些碳氢化合物的活性弱得多, 因此研究还很少. 在本工作中, 我们通过激光溅射产生钒氧团簇阴离子VxOy, 产生的团簇在接近热碰撞条件下与烷烃(C2H6和C4H10)以及烯烃(C2H4和C3H6) 在一个快速流动反应管中进行反应, 飞行时间质谱用来检测反应前后的团簇分布. 在VxOy与烷烃的反应中, 生成了产物V2O6H-和V4O11H-; 在与烯烃的反应中, 产生了相应的吸附产物V4O11X-(X=C2H4或C3H6). 密度泛函理论计算表明: V2O-6和V4O-11可以活化烷烃(C2H6和C4H10)的C—H键, 也可以与烯烃(C2H4和C3H6)发生3+2环化加成反应形成一个五元环结构(-V-O-C-C-O-), C—H键活化与环加成反应都需经历可以克服的反应能垒. 理论计算与实验观测结果相符合. V2O-6和V4O-11团簇都具有氧原子自由基(O·或O-)的成键特征, 活性O-物种也经常出现在钒氧催化剂表面, 因而本研究在分子水平上, 揭示了表面活性氧物种与碳氢化合物反应的机理.     

气相色谱-质谱大体积进样法测定蔬菜、水果中17种农药残留

建立了GC—MS／SIM与大体积进样技术结合测定蔬菜、水果中包括有机磷类、氨基甲酸酯类、有机氯类、菊酯类在内的17种农药的方法。样品经丙酮提取，OASIS HLB固相萃取小柱净化后，采用GC—Ms的选择离子模式和大体积进样技术进行测定，能够使相对检出限降低1～2个数量级。大多数农药的线性范围为0．05～10mg／kg，相关系数为0．9943—0．9996，相对标准偏差为3．5％-10．3％，回收率范围在77％～107％之间．方法能满足果蔬中17种农残限量的的检测要求，具有灵敏、快速、重复性好的特点。