无烟煤氧化制苯多羧酸

对阳泉无烟煤进行了碱－氧气氧化研究。发现反应温度、碱的用量、反应时间以及氧初压是影响和控制水溶酸产率和反应速度的重要因素。最佳氧化条件为：温度２６０℃，碱煤比３．２８：１，反应时间２ｈ，氧初压５．５ＭＰａ。在最佳氧化条件下水溶酸的产率高达６６．０％，其中６７．４％为苯多羧酸。并采用红外光谱和气相色谱对反应产物进行了定性和定量分析。     

Chemiluminescence flow system for the determination of ammonium ion

A novel chemiluminescence (CL) system for ammonium ion combined with flow-injection analysis is presented in this paper. It is based on the CL reaction between luminol, immobilized electrostatically on an anion-exchange column, and chlorine electrochemically generated on-line via a platinum electrode from hydrochloric acid in a coulometric cell. Ammonium ion reacts with chlorine and decreases the observed CL intensity. The system responds linearly to ammonium ion concentration in the range 1.0-100 muM, and the detection limit is 0.4 muM. A complete analysis, including sampling and washing, could be performed in 1 min with a relative standard deviation of <6.0%. The system is stable for over 500 determinations and has been applied successfully to the determination of ammonium ion in rainwater samples.     

Organic Reactions in Ionic Liquids： An Efficient Method for the Synthesis of Phenacyl Esters by Reaction of Carboxylic Acids with α-Bromoacetophenone Promoted by Potassium Fluoride

An efficient method is reported for the synthesis of phenacyl esters by reaction of carboxylic acids with a-bromoacetophenone promoted by potassium fluoride in ionic liquid [Bmim]PF6, the yield of the reaction is almost quantitative and the products are essentially pure.     

热缓冲剂对稀土贮氢合金吸氢动力学的影响

以铜粉作为热缓冲剂添加到稀土贮氢合金粉中,应用动力学机理函数计算机拟合的方法,研究了ML(NiCoMnAlCu)5和Mm(NiCoMnAlCu)5(ML为富镧混合稀土金属,Mm为富铈混合稀土金属)在α+β相区恒温吸氢动力学.研究结果表明,当铜粉与贮氢合金粉达到一定比例时,能够消除热传导对吸氢动力学的影响.富铈稀土合金和富镧稀土合金吸氢均受氢在β相的内扩散控制,合金中随La/Ce比例的减小,吸氢速度加快.     

Interaction of tetrandrine with human serum albumin: a fluorescence quenching study.

The interaction of tetrandrine with human serum albumin (HSA) was studied by measuring fluorescence quenching spectra, synchronous fluorescence spectra and ultra-violet spectra. The fluorescence quenching spectra of HSA in the presence of tetrandrine showed that tetrandrine quenched the fluorescence of HSA. The quenching constants of tetrandrine on HSA were determined using the Stern-Volmer equation. Static quenching and non-radiation energy transfer were the two main reasons leading to the fluorescence quenching of HSA by tetrandrine. According to the F?rster theory of non-radiation energy transfer, the binding distances (r) and the binding constants (K(A)) were obtained. The thermodynamic parameters obtained in this study revealed that the interaction between tetrandrine and HSA was mainly driven by a hydrophobic force. The conformational changes of HSA were investigated by synchronous spectrum studies.     

Diterpenoids of Isodon macrophylla

Two new ent‐abietane diterpenoids, macrophynin E ( 1 ) and macrophynin F ( 2 ), and a known related ent‐abietanoid (?)‐lambertic acid ( 3 ), together with four known ent‐kauranoids, were isolated from the roots and aerial parts of Isodon macrophylla, respectively. The structures of the new compounds were elucidated on the basis of spectroscopic‐data analysis and chemical correlations.     

Cellulose hydrolysis using zinc chloride as a solvent and catalyst

Cellulose gel with < 10% of crystallinity was prepared by treatment of microcrystalline cellulose, Avicel, with zinc chloride solution at a ratio of zinc chloride to cellulose from 1.5 to 18 (w/w). The presence of zinc ions in the cellulose gels enhanced the rate of hydrolysis and glucose yield. The evidence obtained from X-ray diffraction, iodine absorption experiments; and Nuclear Magnetic Resonance spectra analysis suggested the presence of zinc-cellulose complex after Avicel was treated with zinc chloride. Zinc-cellulose complex was more susceptible to hydrolysis than amorphous cellulose. Under the experimental condition, cellulose gels with zinc ions were hyrolyzed to glucose with 95% theoretical yield and a concentration of 14% (w/v) by cellulases within 20 h. The same gel was hydrolyzed by acid to glucose with 91.5% yield and a concentration of 13.4% (w/v).     

Bimetallic reactivity. One-site addition two-metal oxidation reaction of dioxygen with a bimetallic dicobalt(II) complex bearing five- and six-coordinate sites

The di-Co(2+) complex, [Co(2+)(mu-OH)(oxapyme)Co(2+)(H(2)O)](+), contains an unsymmetrical binucleating ligand (oxapyme) which provides five- and six-coordinate metal sites when a hydroxide bridge is introduced. This complex absorbs 1 equiv of O(2) irreversibly in solution, producing an unstable di-Co(3+) oxygenated product. The oxygenated product has been studied at low temperatures, where its electronic absorption and (1)H NMR spectra were recorded. It is probable that the oxygenation reaction involves a one-site addition two-metal oxidation reaction to produce an end-on-bonded peroxide ligand at the available coordination site, giving the complex [Co(3+)(mu-OH)(oxapyme)Co(3+)(mu(1)-O(2))](+). Addition of 1 equiv of HClO(4) to this oxygenation product gives a stable peroxide complex, [Co(3+)(mu,eta(1):eta(2)-O(2))(oxapyme)Co(3+)](2+), where one of the oxygen atoms bridges the two metals and is sideways bonded to one of the metals. The formation of this stable complex involves expulsion of the OH(-) bridge. Addition of NO(2)(-) to the sideways-bonded peroxide complex leads to the formation of another stable complex, [Co(3+)(mu,eta(1):eta(1)-O(2))(oxapyme)Co(3+)(NO(2))](+), where the peroxide forms a classic di-end-on bridge to the two metals. Both of these complexes have been fully characterized. Addition of acid to this second stable dioxygen complex leads to the release of HNO(2) and the formation of the mu,eta(1):eta(2) sideways-bonded peroxide complex.     

Self-assembly in palladium(II) and platinum(II) chemistry: the biomimetic approach

The self-assembly of complex cationic structures by combination of cis-blocked square planar palladium(II) or platinum(II) units with bis(pyridyl) ligands having bridging amide units has been investigated. The reactions have yielded dimers, molecular triangles, and polymers depending primarily on the geometry of the bis(pyridyl) ligand. In many cases, the molecular units are further organized in the solid state through hydrogen bonding between amide units or between amide units and anions. The molecular triangle [Pt(3)(bu(2)bipy)(3)(mu-1)(3)](6+), M = Pd or Pt, bu(2)bipy = 4,4'-di-tert-butyl-2,2'-bipyridine, and 1 = N-(4-pyridinyl)isonicotinamide, stacks to give dimers by intertriangle NH.OC hydrogen bonding. The binuclear ring complexes [[Pd(LL)(mu-2)](2)](CF(3)SO(3))(4), LL = dppm = Ph(2)PCH(2)PPh(2) or dppp = Ph(2)P(CH(2))(3)PPh(2) and 2 = NC(5)H(4)-3-CH(2)NHCOCONHCH(2)-3-C(5)H(4)N, form transannular hydrogen bonds between the bridging ligands. The complexes [[Pd(LL)(mu-3)](2)](CF(3)SO(3))(4), LL = dppm or dppp, L = PPh(3), and 3 = N,N'-bis(pyridin-3-yl)-pyridine-2,6-dicarboxamide, and [[Pd(LL)(mu-4)](2)](CF(3)SO(3))(4), LL = dppm, dppp, or bu(2)bipy, L = PPh(3), and 4 = N,N'-bis(pyridin-4-yl)-pyridine-2,6-dicarboxamide, are suggested to exist as U-shaped or square dimers, respectively. The ligands N,N'-bis(pyridin-3-yl)isophthalamide, 5, or N,N'-bis(pyridin-4-yl)isophthalamide, 6, give the complexes [[Pd(LL)(mu-5)](2)](CF(3)SO(3))(4) or [[Pd(LL)(mu-6)](2)](CF(3)SO(3))(4), but when LL = dppm or dppp, the zigzag polymers [[Pd(LL)(mu-6)](x)](CF(3)SO(3))(2)(x) are formed. When LL = dppp, a structure determination shows formation of a laminated sheet structure by hydrogen bonding between amide NH groups and triflate anions of the type NH-OSO-HN.     

A zwitterion of 1,5‐bis­(2‐hydroxy­benzamido)‐3‐aza­pentane: a two‐dimensional hydrogen‐bonding network involving dimers

The title compound, 2‐{N‐[2‐(2‐hydroxy­benzamido)ethyl­ammonio­ethyl]amino­carbon­yl}phenolate, C₁₈H₂₁N₃O₄, crystallizes in a zwitterionic form as a result of inter­molecular proton transfer and possesses a negatively charged phenolate group and a protonated amino group. The 2‐hydroxy­benzamide and 2‐(amino­carbonyl)­phenolate moieties attached to the two ends of the C—C—N—C—C backbone adopt a cis conformation in relation to this backbone. All N‐ and O‐bound H atoms are involved in hydrogen‐bond formation; the zwitterions are first linked into head‐to‐tail dimers, which are further organized into a two‐dimensional network parallel to the crystallographic bc plane.