多环芳烃在盐溶液中盐析常数和活度系数的研究

研究盐类对多环芳烃溶解度的影响,不仅涉及盐效应各种理论的研究,而且在化工分离、环境治理上也有重要的实际意义。本文研究了25℃下7种多环芳烃在NaCl水溶液中的活度系数和盐析常数。计算并比较了萘和联苯的盐析常数以及5种多环芳烃在被正辛醇饱和的NaCl水溶液中的活度系数和盐析常数。     

Synthesis and properties of 1-bromo-2,3,5,6-tetrakis(3-pentyl)benzene: a highly sterically hindered aryl bromide

The preparation of 1-bromo-2,3,5,6-tetrakis(3-pentyl)benzene is reported. The ¹H and ¹³C NMR spectra indicate the presence of rotational isomers at room temperature which interconvert on heating. Coalescence of the NMR peaks for the methine and methylene aliphatic protons is observed at 100–120 °C. The conversion of this aryl bromide to the corresponding aryllithium is reported. Similar but less bulky aryl bromides have also been synthesised.     

Annelation of the thiazole ring to 1,2,4-triazines by tandem AN—AN or SN H—SN H reactions

The reactions of 3-aryl-1,2,4-triazines with aromatic thioamides and 4-arylthiosemicarbazides in acetic anhydride at room temperature afforded cyclic products of the tandem nucleophilic addition reactions, viz., tetrahydrothiazolo[4,5-e]-annelated 1,2,4-triazines, in good yields. The latter underwent aromatization in the presence of potassium permanganate.     

Infinite dilution activity coefficents of hydrocarbons in tetra-n-alkyltin solvents between 40 and 60°C measured by gas-liquid chromatography

Infinite dilution activity coefficients for twenty-three hydrocarbons in tetra-n-amyltin (TAT) and in tetra-n-lauryltin (TLT) at several temperatures between 40 and 60°C were measured by gas liquid chromatography. The results, together with those obtained in an earlier paper in tetra-n-octyltin (TOT), are compared and discussed in terms of the equation of state theory of Flory and of the lattice fluid theory of Sanchez and Lacombe.     

硫存在下Beta沸石负载钯催化剂上的芳烃加氢性能研究

采用浸渍和离子交换方法，制备了一系列H-Beta沸石负载钯催化剂，并用XRD，N2吸附和氨程序升温脱附进行了表征。采用连续流动固定床反应器，在总压4 MPa，270 ℃，液体空速为16 h－1和硫的质量分数为100×10－6的条件下进行了四氢萘的加氢反应。实验结果表明，钯催化剂的催化性能与催化剂制备方法及载体的硅铝比有关系。对Pd/Beta25(25是硅铝比，下同)来说,离子交换(IE)催化剂的加氢活性高于对应的初湿浸渍(IWI)样品。对于所有离子交换催化剂，Pd/Beta80(IE)在整个反应期间催化活性及抗硫性最好。Pd/Beta25(IE)四氢萘的初始转化率高达77％，失活最快，8 h降到10％；Pd/Beta60(IE)初始转化率为60％，8 h后为16％；Beta80负载催化剂最稳定，起始和8 h后转化率分别为75％和55％。离子交换的Beta80负载Pd催化剂的优良催化活性可以归结为催化剂中有较高比例的中强和强酸性位的存在，尤其中强酸比例较高，同时较多中孔的存在也是其中的影响因素之一。少量Al2O3的添加可以改善催化剂的活性。     

芳酰胺-吖啶分子钳对中性分子的识别性能. II. 新型吖啶类分子钳的研究

采用差紫外谱法研究了新型芳酰胺-吖啶分子钳(1～7)对苯胺、苯二胺(邻,间,对)等中性分子的识别性能.测定了结合常数(K_a)和自由能变化(△G°),结果表明,所有的分子钳受体与所考察的客体分子均形成1∶1型超分子配合物.识别作用的主要推动力为多重氢键、van der Waals等的协同作用.主客体间尺寸/形状匹配、几何互补等因素对识别性能均有重要的影响.利用核磁氢谱与计算机模拟作为辅助手段对主要的实验结果与现象进行了解释.     

FTIR STUDIES ON THE MODEL POLYURETHANE HARD SEGMENTS BASED ON A NEW WATERBORNE CHAIN EXTENDER DIMETHYLOL BUTANOIC ACID （DMBA）

Three model polyurethane hard segments based on dimethylol butanoic acid (DMBA) and 1,6-hexane diisocyanate (HDI), toluene diisocyanate (TDI) and 4,4‘-diphenylmethane diisocyanate (MDI) were prepared by the solution method.Fourier Infrared (FTIR) spectroscopy was employed to study the H-bonds in these model polyurethanes. The model polyurethane hard segment prepared from HDI and 1,4-butanodiol (BDO) was used for comparison. It was found that the incorporation of the pendent carboxyl through DMBA into the model hard segments weakens the original NH…O=C H-bond but gives more H-bond patterns based on the two H-bond donors, urethane NH and carboxylic OH. The carboxylic dimer is one of the main H-bond types and is stronger than another main H-bond type NH…O=C. In addition, the H-bond in aromatic model hard segments is stronger than that of aliphatic hard segments. The appearance of the free C:O and the fact that almost all N-H is H-bonded suggest that there possibly exist either the third H-bond acceptor or the H-bond formed by one acceptor with two donors.     

3,6-二甲基-9-芳基-1,8-二氧代-2,7,10-三氧杂蒽的合成及晶体结构

以芳醛、6 甲基 4 羟基 2 吡喃酮为原料 ,醋酸酐为溶剂合成了一系列 3 ,6 二甲基 9 芳基 1,8 二氧代 2 ,7,10 三氧杂蒽 ,产物的结构经红外、核磁、元素分析及X射线衍射法表征 ;并对反应过程提出了可能的机理     

微波辐射下无溶剂合成4－芳基－5－乙氧羰基－6－甲基-3，4－二氢吡啶－2－酮

以芳醛、乙酰乙酸乙酯、麦氏酸和醋酸铵为原料，在无溶剂条件下用微波辐射 后合成了一系列4－芳基－5－乙氧羰基－6－甲基－3，4－二氧吡啶－2－酮。     

Understanding the Reactivity of Planar Polycyclic Aromatic Hydrocarbons: Towards the Graphene Limit

The Diels–Alder reactivity of maleic anhydride towards the bay regions of planar polycyclic aromatic hydrocarbons was explored computationally in the DFT framework. The process becomes more and more exothermic and the associated activation barriers become lower and lower when the size of the system increases. This enhanced reactivity follows an exponential behavior that reaches its maximum for systems having 18–20 benzenoid rings in their structures. This peculiar behavior was analyzed in detail by using the activation strain model of reactivity in combination with energy decomposition analysis. The influence of the change in the aromaticity of the polycyclic compound during the process on the respective activation barriers was also studied.