芳醚酮大环封端聚酰亚胺的合成与交联

本文制备了一种含硫醚键环状芳醚酮单体, 并将其引入聚酰亚胺中, 在不存在引发剂的条件下, 能开环交联反应制备出全芳香高热稳定的可交联聚酰亚胺.     

气相色谱-微波等离子体发射光谱的研究 I. 化合物结构对经验式测定的影响

本文以烯烃、芳烃、多核芳烃、烯烃-烷烃混合物、烯烃-多核芳烃混合物、氯代烃和溴代烃等类型的化合物为代表, 考察了化合物结构对气相色谱-微波等离子体发射光谱联用测定化合物经验式结果的影响。对属于同系物的烃类选其中任一种为参比物, 测定准确度不受化合物结构的影响; 对含有非同系物的混合物, 如烯烃-多核芳烃, 参比物和被测物的结构对测定结果准确度有一定的影响, 选择其中的非同系物作参比物时, 所测得的经验式准确度相对较差; 含卤素原子的化合物结构对经验式测定影响较大, 必须选择结构相近(碳架结构和卤素原子数相近)的化合物作为经验式测定的参比物。     

Photoinduced charge separation in titania nanotubes

The photocatalytic one-electron oxidation reaction of an aromatic compound during UV light irradiation of titania nanotubes and nanoparticles was investigated using time-resolved diffuse reflectance spectroscopy. Remarkably long-lived radical cations of the aromatic compound and trapped electrons were observed for the nanotubes when compared to those for nanoparticles. The influences of the morphology on the one-electron oxidation process of an aromatic compound adsorbed on the surface were discussed in terms of the charge recombination dynamics between the radical cation and electrons in TiO2.     

Enhanced positive secondary ion emission from substituted polynuclear aromatic hydrocarbon/sulfuric acid solutions

Secondary ion mass spectra of singly substituted aromatic hydrocarbon/H₂SO₄ solutions showed intense aromatic molecular ion and protonated aromatic molecule peaks characteristic of dissolved aromatic compounds from a number of aromatic compound classes, including acids, aldehydes, ketones, nitriles and nitrogen heterocycles. The presence of simultaneously abundant peaks for molecular ions and protonated molecules in secondary ion mass spectra of each aromatic compound/sulfuric acid solution is consistent with known or expected gas-phase proton transfer chemistry. The ratio of intensities, M⁺˙:[M + H]⁺, appears to be determined by sulfuric acid solution chemistry of the compound. Spectra obtained from 1–2 μl samples were relatively free from chemical noise and persisted for up to 20 min. Detection limits for some substituted aromatic compounds are estimated to be 10^?12.     

Efficient synthesis of N-alkyl-2,7-dihalocarbazoles by simultaneous carbazole ring closure and N-alkylation

The N-alkyl-2,7-dihalocarbazole as the main product was formed by the reaction of 4,4′-dihalo-2-nitrobiphenyl with aromatic nitro compound and trialkyl phosphite. The presence and crucial role of aromatic nitro compound causes simultaneous carbazole ring closure and N-alkylation unlike the Cadogan ring closure where non-alkylated carbazole is formed as a main product. In addition, the mixture of aromatic nitro compound and trialkyl phosphite was found to be a possible N-alkylating agent for heterocycles, such as carbazole or indole.     

Regiospecific oxidation of an alkyl group of aromatic amine to carbonyl group by DDQ in aq.medium

The regiospecific oxidation of alkyl group of both sterically hindered and unhindered aromatic amine to corresponding carbonyl compound was done in aq. medium by using DDQ. The optimized reaction protocol was found to be most simple, high yielding and novel method for oxidation of alkyl group of aromatic amine in to its carbonyl compound.     

Umpolung of reactivity of allylsilane,allylgermane, and allylstannane via their reaction with thallium (III) salt: a new allylation reaction for aromatic compound

A new direct allylation of the aromatic compound has been developed. A combination of allylsilane, allylgermane, or allylstannane and thallium (III) trifluoroacetate gave rise to an allyl cationic species which was allowed to react with an aromatic compound, a nucleophile, to give allylation product(s) in good yields.     

Photochemical Synthesis of Cyclopentadienyl-hexamethylbenzene-iron Tetrafluoborate

As a new type of photoinitiator, cyclopentadienyl-aryl-iron tetrafluoroborate has received much attention^[1]. We^[2] have improved the synthesis method of cyclopen-tadienyl-benzene-iron tetrafluoroborate reported by the literature^[3,4]. This synthetic method is to reflex the mixture of ferrocene and fluid aromatic compound; the cyclopentadiene of ferrocene was replaced by the incoming aromatic compound. However, this method is rather limited if the ligands are solid aromatic compounds.     

Determination of 2-hydroxy-4-methoxybenzaldehyde in roots of Decalepis hamiltonii (Wight & Arn.) and Hemidesmus indicus R.Br

The roots of Decalepis hamiltonii and Hemidesmus indicus are aromatic and possess the crystalline compound 2-hydroxy-4-methoxybenzaldehyde as the major compound (> 90%) in their volatile oils. A gas chromatographic procedure was developed for the assay of 2-hydroxy-4-methoxybenzaldehyde in both fresh and dried roots of different origin. Benzyl butyrate was used as the internal standard. Among the methods tried, steam hydrodistillation was suitable for extraction of the volatile oils. The quantity of this aromatic compound varied from 0.03 to 0.54%.     

Aromatic polyesterimides

Several novel arylene bis(trimellitate) dianhydrides have been prepared by: the acidolysis reaction of trimellitic anhydride (TMA) with aromatic diacetoxy compounds and the reaction of trimellitic anhydride monoacid chloride with diphenols. These novel aromatic bisesteranhydrides were reacted with aromatic diamines in polar solvents to give high molecular weight polyamic acid solutions. Heat converted these soluble precursors to insoluble aromatic polyesterimides having good physical and thermal properties. The mechanism of the acidolysis reaction between an aromatic acid and an aromatic acetoxy compound is briefly discussed.     

Kinetics of the liquid-phase catalytic hydrogenation of chlorine-containing aromatic nitro compounds in the presence of pyridine

We have analyzed experimental kinetic data for nitro compound consumption, for the formation of the corresponding amino product, and for the accumulation of intermediate products and by-products in the hydrogenation of chlorine-containing aromatic nitro compounds. The reaction has been carried out under static conditions over a platinum catalyst on a porous support in the presence of pyridine. The effect of the admixture on different hydrogenation steps of a chlorine-containing aromatic nitro compound has been quantitatively interpreted.     

芳香寡聚磺酸酯桥联大环化合物的合成及其对Sn2+和Bi3+的识别作用

以4,6-二烷氧基-1,3-苯二磺酰氯和芳香二酚为原料,三乙胺作缚酸剂,二氯甲烷作溶剂,采取一步成环法合成了3种磺酸酯桥联大环化合物。合成产物的结构用IR、¹H NMR、¹³C NMR和MALDI-TOF等技术手段进行了确认。利用紫外光谱分析的方法研究了4,6,16,18-四正戊氧基-11,23-二甲基-1,3,13,15-四磺酸酯间苯芳香大环(5)对Ca²⁺、Pb²⁺及部分过渡金属等20种金属离子的识别。结果发现,其对Sn²⁺显示出一定的选择性,由于Sn²⁺和Bi³⁺协同作用的影响,在化合物5-Sn²⁺的体系中加入Bi³⁺,紫外吸收光谱在325 nm左右的吸收增强了许多,这说明化合物5对Bi³⁺显示出优于Sn²⁺的较好选择性。     

Photoreaction of benzofuroxan

Benzofuroxan 5 , upon irradiation using a high pressure mercury lamp with a Pyrex filter in acetonitrile containing a little water, afforded 1H-azepine-2,7-dione 6 . The initial stage of this reaction would be formation of a highly reactive intermediate possessing two nitrile oxide functions. On the other hand, when compound 5 was irradiated using a low pressure mercury lamp in acetonitrile containing a little water, it afforded 6H-furazano[4,5-c]carbazole 3-oxide 11 and compound 6 . The structure of compound 11 was determined by an X-ray structural analysis. In the presence of an aromatic hydrocarbon, the formation of compound 11 was decreased and that of compound 6 was increased. Mechanistic studies on the photoreaction suggest that the photosensitized formation of compound 6 with the aromatic hydrocarbon may be carried out by the reabsorption of the fluorescence of it near 365 nm and the presence of it may quench the formation of compound 11 .     

Identification of aromatic sulphonic acids by reaction electrophoresis on paper

A method was elaborated to establish the number of sulphonic groups bound to the aromatic ring of aromatic acids by means of a paper electrophoretic separation of the original compound from the derivative. The difference between the mobilities is directly proportional to the number of substituted sulphonic groups.     

Review of Sublimation Thermodynamics of Polycyclic Aromatic Compounds and Heterocycles

This review details sublimation vapor pressure and thermodynamic data on 85 polycyclic aromatic compounds and heterocycles from the early 1900s through 2012. These data were collected using a variety of vapor pressure measurement techniques, from effusion to gas saturation to inclined‐piston manometry. A brief overview of each measurement technique is given; these methods yield reproducible sublimation vapor pressure data for low volatility organic compounds such as polycyclic aromatic compounds and heterocycles. Several conclusions can be drawn from this literature survey, specifically that there remains a dearth of data on the sublimation thermodynamics (and fusion thermodynamics) of heteroatomic high molecular weight aromatic compounds, inhibiting a holistic understanding of the effect of specific heteroatoms and substituent position on the thermodynamics of these compounds. However, we can clearly see from the data that there are a variety of potential intermolecular interactions at work that generally tend to increase the enthalpy of sublimation and decrease the vapor pressure of a substituted polycyclic aromatic compound/polycyclic heterocycles versus its parent compound.     

Organolithiums by reductive lithiation: the catalytic aromatic method versus the use of preformed aromatic radical-anions. Naphthalene can behave as a catalyst or an inhibitor

Two common modes, using aromatic radical-anions for reductive lithiation, the replacement of a C-heteroatom bond with a C-Li bond, have been compared with regard to yield and the mildness of reaction conditions required. It was found that the use of preformed radical-anions generally resulted in higher yields and milder reaction conditions than the ‘catalytic’ method in which catalytic amounts of the aromatic compound are used and the radical-anion is generated and used in situ. The one apparent exception is N-phenylaziridine, but it is shown that in this case the aromatic compound, naphthalene, is actually an inhibitor rather than a catalyst. Rational mechanistic explanations are given.     

Peculiar transformation of a nonaromatic Al(4)Cl(4)(NH(3))(4) into an aromatic Na(2)Al(4)Cl(4)(NH(3))(4)

We analyzed the molecular orbitals for a Al(4)Cl(4)(NH(3))(4) compound, which is a model of the (AlBr x NEt(3))(4) crystal structure recently reported by Schn?ckel and co-workers. We found that even though Al(4)Cl(4)(NH(3))(4) contains a planar square Al(4) cluster it is not an aromatic compound. However, the addition of two sodium atoms to Al(4)Cl(4)(NH(3))(4) yields a new Na(2)Al(4)Cl(4)(NH(3))(4) compound which is a pi-aromatic molecule. We hope that prediction of this new compound will facilitate a synthesis of aluminum aromatic solids.     

Capillary column gas chromatography of environmental polycyclic aromatic compounds

The methodologies are described for isolating clean fractions of polycyclic aromatic compounds from diverse environmental samples such as air particulate matter, sediments, and fish tissue. The common step in all procedures is the separation of the polycyclic aromatic compound fraction into well-defined chemical classes by adsorption chromatography on an alumina column. These procedures greatly facilitate the detailed characterization of the polycyclic aromatic hydrocarbons, sulfur heterocycles, and nitrogen heterocycles by capillary column gas chromatography.