三元——假二元系的过量体积

提出测量三元——假二元系(1-x)[(1-y)A+yC]+z[(1-y)B+yC]的过量热力学函数的方法, 测量了在298.15 K下两种假二元系: A=环己烷, B=苯, C=甲苯, 甲基环己烷的过量体积V~E, 用van der Waals单流体模型对实验结果进行了讨论。     

某些Lewis碱与CCl4和CHCl3在298.15K的过量体积

在298.15 K下用连续稀释膨胀计或振动管密度计测量了二甲基甲酰胺(DMF)、二甲基乙酰胺(DMA)、N-甲基吡咯烷酮(NMP)、γ-丁内酯(γ-BL)、二甲基亚砜(DMSO)分别与四氯化碳和三氯甲烷构成的二元系的过量体积。除DMSO+CHCl_2二元系的V~(E-x)曲线为S形外, 其余二元系的V~E值均为负值。在所研究的两个系列中, |V_(min)~E|的大小顺序均为: NMP>γ-BL>DMF≈DMA>DMSO     

5-(2’-羧乙基)-6-烷基-3,4-二氢吡喃酮的合成

吡喃酮是许多天然产物的结构单元,我们曾由4-异丁酰基庚二酸在过量醋酸酐及乙酰氯存在下回流得到7-氧代-8,8-二甲基-△~9-六氢香豆素.本文由二氰乙基-β-二酮进行酮解水解反应得到4-酰基庚二酸1_(a-c)。 在过量醋酸酐、乙酰氯存在下由1_a、1_c为底物进行反应没有得到双环的香豆素衍生物.其产物和单纯以乙酐为缩合剂时的产物2_a、2_c相同,产率分别为68％、63％。2_c可在硫酸铁催化     

光学活性α-取代(2-吡啶基)甲胺的对映选择性合成

以2-羟基蒎烷-3-酮为手性助剂, 与2-氨甲基吡啶缩合得到中间体酮亚胺, 经去质子化、不对称烷基化、转胺反应得到光学活性α-取代(2-吡啶基)甲胺, 对映体过量值为89-98%。并提出了过渡态模型, 对对映选择性合成反应作了较为合理的解释。     

3-取代卓酚酮5位偶联产物的溴氧化成环反应

报道了采用溴氧化3-异丙烯基卓酚酮和3-肉桂酰基卓酚酮合成杂环并卓酮化合物的新方法。3-异丙烯基卓酚酮5位偶联产物1a-1f和3-肉桂酰基卓酚酮5位偶联产物3a-3d分别在吡啶介质中与过量溴作用生成5-取代苯偶氮基-7-溴-3-甲基-8-氢环庚并呋喃-8-酮2a-2f和6-取代苯偶氮基-2-苯基-8-溴-4,9-二氢环庚并吡喃-4,9-二酮4a-4d。     

水/有机溶剂双相中郁李醇腈酶催化含硅(R)-酮氰醇对映选择性合成

 研究了水/有机溶剂双相中来源于郁李仁的(R)-醇腈酶催化2-三甲基硅-2-乙酮与2-甲基-2-羟基丙腈对映选择性合成(R)-2-三甲基硅-2-羟基丙腈,初步探讨了反应时间、酶粉颗粒大小、底物浓度、底物配比和酶添加量对转氰反应的影响. 结果表明,适宜的反应条件为: 反应时间96 h左右, 酶粉颗粒大小0.3～0.45 mm, 底物2-三甲基硅-2-乙酮浓度14 mmol/L, 底物2-甲基-2-羟基丙腈与2-三甲基硅-2-乙酮摩尔比2:1, 单位体积反应介质中的酶添加量43.5 g/L左右. 在该优化反应条件下,反应平衡转化率和产物的光学纯度(ee值)均可高达99%. 对比研究发现,郁李醇腈酶催化2-三甲基硅-2-乙酮反应在酶促反应初速率、底物转化率和产物光学纯度等方面均显著优于其碳结构类似物3,3-二甲基-2-丁酮.     

部份互溶体系4-甲基-2-戊醇和水的过量焓研究

使用LKB-2107型流动式微量量热计测定了4-甲基-2-戊醇和水这一部份互溶体系在293.15 K、298.15 K和303.15 K的常压过量焓。测量结果用Redlich-Kister方程作了关联。另外,还用该体系富醇区的过量焓数据拟合NRTL模型的参数与温度关系,推算较高温度下该体系的常压汽液平衡(VLE)组成及泡点。推算值与文献值是接近的。实验试剂4-甲基-2-戊醇由粗品经三次蒸馏提纯,沸点为404.95 K,折光率n_D~(20)1.4113,密度d~(20)0.8067 g cm~(-3),与文献值一致。无水乙醇、尿素均为分析纯。液体试剂在使用前均     

4-氨基-5-[2-(4-氯苯氧甲基)苯并咪唑-1-亚甲基]-1,2,4-三唑-3-硫酮的核磁共振研究

在无水乙醇和KOH存在下,将2-(4-氯苯氧甲基-1-苯并咪唑乙酰肼(1)与CS2反应,合成出了中间体酰肼二硫代甲酸钾盐.此中间体再与过量的水合肼反应,经环化得到一种新化合物4-氨基-5-[2-(4-氯苯氧甲基)苯并咪唑-1-亚甲基]-1,2,4-三唑-硫酮.采用元素分析、IR及NMR技术确定了新化合物的结构,并利用2...     

2,6-二甲基哌啶+水体系临界性质的氘代同位素影响

用等体积法分别确定2,6-二甲基哌啶+水和2,6-二甲基哌啶+重水体系的临界组成, 并测定各自的临界温度. 采用折射率法在较宽温度范围内测定两个体系的温度-折射率(T-n)共存曲线, 利用标φ曲线法将其转化为温度-摩尔分数(T-x)和温度-体积分数(T-φ)共存曲线, 求得临界指数β、指前因子B、Wegner校正项因子B1及与共存曲线直径ρd相关的参数. 研究结果表明, 氘代后, 体系低临界温度下降了约3.2 K, 临界组成和共存曲线形状不变, 在近临界点临界指数β仍符合三维伊辛模型(3D-Ising)的理论值(0.327).     

新型低共熔溶剂的制备、表征及物性研究

以氯化1-丁基-3-甲基咪唑鎓([Bmim]Cl)和二元羧酸为原料,由不同摩尔比混合制备了一类新型低共熔溶剂,采用红外光谱对[Bmim]Cl和二元羧酸之间的作用进行了分析。分别测定了其粘度、电导率、密度、折射率等物理性质,并研究了温度、二元羧酸结构和摩尔比对这些物理性质的影响。结果表明,新型低共熔溶剂的粘度随温度的升高而降低,电导率随温度的升高而增加。温度对两者的影响可以采用VTF方程进行精确地拟合。新型低共熔溶剂的密度随温度的升高而呈线性下降。对新型低共熔溶剂的过量摩尔体积进行计算的结果表明,过量摩尔体积均为正值,二元羧酸对过量摩尔体积的贡献远大于[BMIM]Cl,而结构特性的贡献多于物理作用。折射率和密度随二元羧酸碳数的变化趋势基本相似。     

四氯乙烯光解活泼自由基及其与烃或醇的夺氢反应的ESR研究

本文用自由基捕捉剂2,3,5,6-四甲基亚硝基苯(ND)与ESR相结合的方法研究了四氯乙烯光解活泼自由基及其与烃或醇的夺氢反应, 结果表明:1. Cl_2C=CCl_2光解首先产生Cl_2C=CCl及Cl, 而又可进一步加成为Cl_2C-CCl_3.2. 对于CH_3(CH_2)_nOH(n=3,7)及(CH_3)_2CH(CH_2)_nOH(n=1,2)而言, Cl_2C=CCl(或Cl)分别夺取其α-碳及叔碳上的氢, 以形成CH_3(CH_2)_(n-1)CHOH及(CH_3)_2C(CH_2)_nOH, 并为ND所捕获。3. Cl_2C=CCl(或Cl)分别夺取CH_3(CH_2)_nCH3(n=3,4,5,6), C_6H_5-CH_2CH_3及(CH_3)_2CH(CH_2)_nCH_3(n=1,4), (C_2H_5)_2CHCH_3, C_6H_5CH(CH_3)_2中亚甲基及叔碳上的氢, 以形成CH_3(CH_2)_mCH(CH_2)_(n-m-1)CH_3, C_6H_5CHCH_3及(CH_3)_2C(CH_2)_nCH_3, (C_2H_5)_2CCH_3, C_6H_5C(CH_3)_2.     

Structural effects of solvation of unsaturated fatty acids C18:n in tetrachloromethane found in investigations of the volumetric properties of solutions

The limiting partial molar volumes of solutes and excess molar volumes of their mixtures with nonpolar solvents are calculated on the basis of precise (error ≤ 5·10^?6 g·cm^?3) densitometric measurements for dilute solutions of oleic, linoleic, and linolenic acids in tetrachloromethane at 298.15 K. It is found that self-association processes of the components of the mixtures play the key role in dissolution effects of fatty acids in CCl₄. As the number of C=C double bonds in the acid molecule increases, acid desolvation becomes less pronounced and is accompanied by compression (reduction of volume) of the structural packing of the solvate complex formed due to the strengthening interaction of the acid with tetrachloromethane.     

Isothermal vapor–liquid equilibria of bromochloromethane or 1-bromo-2-chloroethane+tetrachloromethane or benzene. Experimental measurements and analysis in terms of group contributions

Isothermal vapor–liquid equilibria (VLE) have been measured for bromochloromethane+tetrachloromethane or benzene at 298.15 K and 313.15 K, and for 1-bromo-2-chloroethane+tetrachloromethane or benzene at 313.15 K. Bromochloromethane+tetrachloromethane shows azeotropic behaviour in the temperature range covered. These experimental results, along with our previous ones on excess enthalpies, are interpreted with two group contribution models: DISQUAC (DISpersive-QUAsiChemical) and modified (Dortmund) UNIFAC (UNIquac Functional group Activity Coefficients).     

The excess enthalpy of (tetrachloromethane + carbon disulphide) and (tetrachloromethane + dichloromethane) over a range of temperatures and pressures

Measurements of the excess molar enthalpy of (tetrachloromethane + carbon disulphide) and (tetrachloromethane + dichloromethane) have been made using an isothermal high-pressure flow calorimeter. The measurements for (tetrachloromethane + carbon disulphide) cover the range 283.15 to 323.15 K at pressures between 0.1 and 30 MPa. The excess molar enthalpies for (tetrachloromethane + dichloromethane) are reported at 298.15 K at 0.1, 15, and 30 MPa, and at 323.15 K at 0.2 MPa. The thermodynamic consistency of the results is shown by deriving the temperature dependence of the excess molar Gibbs free energy from them and comparing with published experimental values.     

苯、甲苯与某些极性溶剂在293.15 K的过量体积

某些极性有机溶剂与烯烃、芳烃的特殊相互作用,是这些极性溶剂能够将烯烃、芳烃自烷烃中分离的基础。其分离的选择性决定于这种特殊相互作用。 L.J.Andrews认为腈类化合物、酮类化合物能与苯或苯的甲基衍生物生成电荷转移络合物,如苯与四氰基乙烯的络合物。R.F.Weimer和J.M.Prausnitz用紫外分光光度法测定过对-二甲苯与丙腈、丙酮、N-甲基吡咯烷酮等物的分子络合常数。我们也用分光光度法测定过某些芳烃与N-甲基吡咯烷酮的分子络合常数。     

Densities,excess molar volumes,and refractive indices of ethyl acetate and aromatic hydrocarbon binary mixtures

Densities, excess molar volumes, refractive indices, and changes in refractive index on mixing for (ethyl acetate  +  benzene, or methylbenzene, or ethylbenzene, or 1-4-dimethylbenzene, or 1-methylethylbenzene, or 1-3-5-trimethylbenzene, or 1-1-dimethylethylbenzene) have been determined atT =  298.15 K. The excess molar volumes and changes in refractive index have been fitted to Redlich–Kister polynomials. The π -electrons interactions of the benzene ring and the peculiar plate shape of the aromatic molecules are noticeably modified by the presence of the ethyl acetate molecules of a different nature. The intermolecular interactions are strongly modified and result in positive excess volumes except for toluene or p -xylene whose values are close to zero. The refractive indices were compared with calculated values using mixing rules proposed by several authors.     

Excess Volumes of 1-Alcohol + Heptane Mixtures at 298.15 and 308.15 K-Application of An Association Model with Flory Interaction Term

Abstract

The excess volumes of 1-pentanol+, 1-hexanol+, 1-heptanol+, 1-octanol+, 1-decanol+ and 1-dodecanol + heptane mixtures were evaluated at 298.15 and 308.15 K from the density data. The excess volumes were found to decrease with the increase in the carbon chain length of alcohol molecules. The temperature coefficient for the excess volumes was also observed to show a decreasing trend from 1-pentanol + to 1-dodecanol + heptane mixtures. The excess volumes were also calculated by combining the individual physical and chemical contributions, evaluated by combining an association model with Flory's free volume theory. Reasonable agreement between the experimental and calculated excess volumes for all the mixtures at 298.15 and 308.15 K was noted.     

Excess heat capacities of binary mixtures of tetrachloromethane with some aromatic liquids at 298.15 K

A Picker flow calorimeter was used to obtain excess heat capacities at 298.15 K for mixtures of tetrachloromethane + toluene, + each of the three xylenes, + ethylbenzene, + mesitylene, and + chlorobenzene. The excess heat capacities are positive in all cases, with the exception of tetrachloromethane + mesitylene. Comparison of the results with values calculated from a “regular associated solution” model supports the view that complex formation occurs in these mixtures.     

4[CuCl(C5H5N)4]·[W10O32]·2(C5H5N)·3H2O的合成及晶体结构

标题化合物是通过(NH_4)_2WS_4, CuCl_2·2H_2O在吡咤溶液中反应制得。晶体呈蓝色, 属三斜晶系, 空间群P1, 晶胞参数为:a=1.3555(7), b=1.3666(5), c=1.7860(13) nm, α=69.08(4)°, β=87.39(5)°, γ=70.72(4)。V=2.907(3) nm, Z=1, D_m=2.56 g cm~(-3)。结构由Patterson法和Fourier法测出。对5692个收集到的独立衍射数据进行计算, 最后R=0.046。结构测定表明, 晶体由W_(10)O_(32)~(4-), [CuCl(C_5H_5N)_4]~+, C_5H_5N和H_2O所组成。W_(10)O_(32)~(4-)的结构见图1, W原子处在O原子的八面体配位中, 彼此共边和共顶点相连。[CuCl(C_5H_5N)_4]~+的结构见图2, Cu原子由1个Cl和4个N原子配位, 呈略有变形的四方锥形, 这种离子是首次报导。C_5H_5N和H_2O填入正负离子堆积的空隙中。