双金属氰化物配合物的制备、表征及催化性能

 制备了基于钴氰化锌的双金属氰化物配合物（DMC）催化剂，并\r\n用元素分析、X射线衍射和红外光谱等手段进行了表征，考察了催化剂\r\n的结构与组成对其催化活性的影响以及该催化体系催化环氧烷烃开环聚\r\n合的特点．结果表明，含ZnCl2和叔丁醇的非晶态DMC催化剂具有最高的\r\n催化活性．该催化体系使聚合物的分子量可控，不饱和度很低（＜14μ\r\neq／g），逐步聚合所得到的聚合物的分子量分布较窄（Mn／Mw＜1．4\r\n8）．13CNMR分析结果表明，甲基氧丙环均聚物的链结构具有无规立构\r\n的特点，且链节分布几乎都为头－尾方式．IR分析结果表明，甲基氧丙\r\n环－环氧乙烷共聚物的链结构是无规分布的．     

Enthalpies of Dilution of Aqueous Solutions of NaOH, KOH, and CsOH at 300, 325, and 350°C

Dilution enthalpies, measured using isothermal flow calorimetry, are reported for aqueous solutions of KOH and CsOH at 300°C and 11.0 MPa, 325°C and 14.8 MPa, and for aqueous solutions of NaOH, KOH, and CsOH at 350°C and 17.6 MPa. Previously collected dilution enthalpies for aqueous solutions of NaOH at 300°C and 9.3 MPa and at 325°C and 12.4 MPa were included when fitting the Pitzer parameters. The concentration range of the hydroxide solutions was 0.5–0.02 molal. Parameters for the Pitzer excess Gibbs ion-interaction equation were determined from the fits of the experimental heat data. Equilibrium constants, enthalpy changes, entropy changes, and heat capacity changes for alkali metal ion association with hydroxide ion were estimated from the heat data. For all systems, the enthalpy changes and entropy changes were positive and had accelerating increases with temperature. The resulting equilibrium constants show significant, but smaller, increases with temperature.     

Solubilization of methane,ethane, propane andn-butane in aqueous solutions of sodium dodecylsulfate

The solubilities of methane, ethane, propane, and n-butane were measured in aqueous solutions of sodium dodecylsulfate (NaDS) (0–0.1M) from 15 to 27°C. From these measurements the standard Gibbs energies, entropies, and enthalpies for the process of transferring the solute molecules from the gaseous phase into the solutions were calculated. An approximate relationship was found relating the volume fraction of the micelles to NaDS concentration.     

N-Bromosuccinimide-dibenzoyl peroxide/azabisisobutyronitrile: a reagent for Z- to E-alkene isomerization

N-Bromosuccinimide-dibenzoyl peroxide/azobisisobutyronitrile is used to carry out several types of Z- to E-alkene isomerizations. The NBS-bromination conditions are sufficient for both allylic bromination and alkene isomerization. When the allylic hydrogens are not available in substrates, only the isomerization of the alkene takes place. The present conditions for isomerization of carbon-carbon double bonds are mild and efficient.     

Zur Reaktion von Makrozyklen mit Lanthanoiden. I. Die Struktur von [Li(thf)][(C22H22N4)2Ce] · THF

On the Reaction of Macrocycles with Lanthanoids. I. The Crystal Structure of [Li(thf)][(C₂₂H₂₂N₄)₂Ce] · THF In THF CeBr₃ forms with [(TMTAA)Li₂] the paramagnetic doubledecker complex [Li(thf)][(TMTAA)₂Ce]. The complex crystallizes with 1 Mol THF per formula unit. The structure was characterized by X-ray single crystal structure analysis (space group C2 (No. 5), z = 6, a = 1741.8(2) pm, b = 1622.1(2) pm, c = 2540.4(3) pm, β = 104.72(1)°). The sandwich-like arrangement of the heterocyclic ligands leads to a quadratic-prismatic coordination of the Ce³⁺ ion. One macrocyclic ligand is additionally coordinated by a [Li(thf)]⁺ fragment. The coordination of the Li ion is square pyramidal.     

Investigations of the thermal stability and phase transformations in the system marocco phosphorite—(NH4)3H(SO4)2.NH4HSO4

Different physical chemical methods were used to study the thermochemical processes in a system involving a natural phosphate and complex acid salts of ammonium sulphate. The products of decomposition of the double ammonium salt and the products of their interactions with the phosphate were identified. The formation of ammonium and calcium polyphosphates and the disproportionation of P₃O ₁₀ ^5? and P₂O ₇ ^4? to PO ₄ ^3? and PO ₃ ^? were found to depend on the circumstances of the thermal interactions.     

聚丙烯酰胺与混合表面活性剂的相互作用

通过粘度和紫外吸收光谱的测定，研究了ＰＡＭ与Ｒ１２ＳＯ３Ｎａ－Ｒ１１ＣＯＯＮａ混合表面活性剂之间的相互作用，结果表明，ＰＡＭ可与混合表面活性剂形成复合物，从而使体系表现出典型聚电解质的粘度行为。可能的机理是，以疏水力形成的Ｒ１２ＳＯ３＾－—Ｒ１１ＣＯＯＨ（Ｎａ）预胶束或二聚体通过ＰＡＭ－Ｒ１１ＣＯＯＨ间的氢键力相结合。进而使大分子链上带有大量负电荷，静电斥力引起大分子链伸展，因而产生电粘效应。     

毛细管胶束电动色谱对复方药物有效成分的定量研究

本文报道采用毛细管胶束电动色谱法对复方药物去痛片和感冒灵中有效成分进行了分离和定量研究。以0.05毫米内径、45厘米长的弹性石英毛细管为分离柱,用十二烷基硫酸钠胶束溶液,在选定的实验条件下,各组分在十几分钟内就能很好的分离。采用两点内标法定量,所得结果与HPLC法测定结果相一致。该法具有装置简单,无需价格昂贵的分离柱,样品预处理简单等优点,可在药物分析中推广。     

Incorporation of rare-earth ions in Mg-Al layered double hydroxides: intercalation with an [Eu(EDTA)] chelate

Reaction of an aqueous slurry of an Mg₂Al-NO₃ layered double hydroxide with a four-fold excess of Na[Eu(EDTA)] gives a material which analyses for Mg_0.68Al_0.32(OH)₂[Eu(EDTA)]_0.10(CO₃)_0.11·0.66H₂O. The interlayer spacing of the material is 13.8 Å, corresponding to a gallery height of 9.0 Å, which accords with the maximal dimensions (9-10 Å) of the anion in metal-EDTA complex salts as determined by single crystal X-ray diffraction. Geometrical considerations show that the charge density on the layered double hydroxide layers is too high to be balanced by intercalation of [Eu(EDTA)]⁻ alone, necessitating the co-intercalation of carbonate ions which have a much higher charge density.     

Sensing of Trace Amounts of Dodecyl Benzene Sulfonate by Solid Phase Spectrophotometry

A very simple, selective and sensitive spectrophotometric method for the determination of dodecyl benzene sulfonate (DBS) has been investigated. In this method, the ion pair of DBS and methylene blue was adsorbed onto plasticized poly(vinylchloride) membrane as a solid phase extraction medium. The absorbance of the blue membrane was measured at 660nm against a blank membrane using a spectrophotometer. The influence of type and amount of plasticizer, pH, concentration of methylene blue, temperature of sample solution and time of extraction on the absorbance of membrane was studied. Linear calibration was obtained over a concentration range of 0.1 to 6.5µgmL^–1 of DBS. The method was applied to the determination of DBS in different commercial detergents. The precision and accuracy of the method is comparable with the conventional standard method. This method is cost-effective, and the use of organic solvent such as chloroform is completely eliminated.