双吡啶盐及其聚合物的研究Ⅱ.4,4’-(-1,4-苯撑-)-双-[N-烷(芳)基-2,6-二苯基]-吡啶盐及其聚合物对某些芳香酮还原反应的催化作用

在4,4’-(1,4-苯撑)-双-IN-烷(芳)基-2,6-二苯基I吡啶盐及其聚合物的催化下,二苯甲酮和苯乙烯基苯甲酮与中性条件下的锌粉发生双分子还原反应,生成相应的邻二叔醇;而结构类似的环状酮却主要发生单分子还原反应.双吡啶盐及其聚合物的结构和反应介质的极性对还原反应的速度有很大影响。本文对催化反应的机理也进行了讨论。     

Determination of average molecular polarizabilities of polycyclic aromatic hydrocarbons directly from retention indices

Summary A significant correlation has been found between the retention indices of polycyclic aromatic hydrocarbons on non-polar stationary phases and the average molecular polarizabilities of the molecules separated on these phases. Equations have been derived for the determination of the average molecular polarizabilities, directly from the retention indices.     

Tensor magneto-optical properties of some carboxylate anions

The Cotton—Mouton effect was used for the study of benzoate, phthalate. isophthalate, and terephthalate anions. The additive tensor characteristics of optical polarizability and magnetic susceptibility ellipsoids have been calculated for C(Ar)-COO^– and . The spatial structures of mono- and deprotonated phthalate anions have been discussed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 874–876, May, 1993.     

Analysis of light hydrocarbons C1–C5 with Porous Layer Open Tubular fused silica columns of aluminum oxide. Part 1: The column

A method is described for the preparation of a Porous Layer Open Tubular (PLOT) fused silica column coated with submicron particles of aluminum oxide for the analysis of light hydrocarbons. The column is thermally stable and provides reproducible analytical data over a long period of time. The column can be operated at temperatures easily controlled by commercially available gas chromatographic apparatus. 1,3-Butadiene is retarded much more than its principal impurities: thus the polarity of aluminum oxide is extremely useful for butadiene analysis because none of the contaminants is obscured by the butadiene peak. The analysis of the 16 most common C₁–C₄ hydrocarbons is achieved within 5 min at 60°C with helium as the carrier gas. Conditioning of the carrier gas with water vapor from CuSO₄.5H₂O to decrease the activity of the aluminum oxide is described. Some applications of a 30 m × 0.32 mm aluminum oxide PLOT column are given.     

Polymerization,structure and thermal properties of ODPA-DMB polyimide films

A new high molecular weight polyimide based on 4,4-oxidiphthalic anhydride (ODPA) dianhydride and 2,2-dimethyl-4,4-diaminobiphenyl (DMB) diamine has been synthesizedvia a one-step polymerization method. This polyimide is soluble in phenolic solvents. Films from 7 to 30 m thick were cast from the polymer solution and show in-plane orientation on a molecular scale detected by Fourier transform infrared spectroscopy experiments. This anisotropic structure leads to anisotropic optical properties arising from two different refractive indices along the inplane and out-of-plane directions. ODPA DMB possesses high thermal and thermo-oxidative stability. The glass transition temperature has been determined to be 298 °C. Dynamic mechanical analyses show two relaxation processes appearing above room temperature: the - and the -relaxation processes. The -relaxation corresponds to the glass transition while the -relaxation is a secondary relaxation process associated with the non-cooperative subsegmental motion.Dedicated to Professor Bernhard Wunderlich on the occasion of his 65th birthdayYHK acknowledges the support from the Yonam Foundation, Korea. This work was also supported by the Center of Molecular and Microstructure of Composites (CMMC) of NSF/EPIC/Industry, SZDC gratefully acknowledges the support from his PYI Award (DMR-9157738) from the National Science Foundation.     

Thermal study of glass transitions in binary systems of simple hydrocarbons

Glass transition phenomena of four binary systems composed of simple hydrocarbons were studied by means of the differential thermal analysis (DTA). For all the systems, a definite glass transition was observed and a monotonous relation between the glass transition temperature (T _g) and composition (x) was obtained. The composition dependence ofT _g was analyzed in terms of the entropy theory based on the regular solution model. The theoretical prediction could not reproduce our results other than (1-butene)_x(1-pentene)_1?x system. This disagreement is considered to be due to deviations of the present systems from the regular solution, and the accompanying excess configurational entropy S_c ^E was estimated as a function of composition. Extraordinarily large values of S _c ^E ? were obtained for (propene)_x(propane)_1?x and (propene)inx(1-pentene)_1?x systems.     

Sulfur-containing polymers by the reaction of diphenyl sulfide with sulfur chlorides

The electrophilic reaction of sulfur dichloride with diphenyl sulfide proceeds efficiently at room temperature to yield oligo(phenylene sulfide) in the presence of a catalytic amount of Fe powder. Sulfur dichloride shows higher reactivity than sulfur monochloride. The reaction is promoted through the activation of sulfur dichloride by Fe powder. The polymeric product contains a linear structure linked by disulfide and sulfide bonds.     

取代芳烃对某些生物急性毒性的拓扑学研究

提出了成键原子的生物活性值(ai),并建立其连接性指数(mA).其中的0A、1A与取代芳烃对斜生栅列藻、日本长腿蛙蝌蚪、绿藻等三种生物的急性毒性关连,相关系数(R)依次为0.9516、0.9564、0.9335,优于相应文献的研究成果.证明mA与取代芳烃生物活性的相关性优于著名的Kier指数(mXv).     

KF/Al_2O_3催化的羰基与活性亚甲基化合物的缩合反应

在KF/Al_2O_3催化下,芳香醛与氰乙酸乙酯或氰乙酰胺发生羰基与亚甲基的缩合反应,得到高产率的缩合产物,且为E式结构。     

Electrochemical Amination of Benzene in Aqueous Solutions of Sulfuric Acid and an Organic Solvent

Electrolysis of the Ti(IV)–NH₂OH–C₆H₆ system in 11 M H₂SO₄ reveals that out of four organic solvents—methanol, formic acid, acetonitrile, and acetic acid—only the last two meet conditions imposed on solvents to be used in indirect cathodic amination of aromatic compounds. They improve the aromatic substrate solubility in the catholyte and affect the process mechanism, determining, together with other factors, the substitution's rate and selectivity.