杂多酸盐K7[PTi2W10O40]·6H2O与牛血清白蛋白相互作用的研究

Under the imitated physiological condition of animal body, the interactions of heteropoly salt (PM-19) with bovine serum albumin (BSA) were investigated by fluorescence and absorption spectroscopy. It was shown that this compound had a quite strong ability to quench the fluorescence launching from BSA. After analyzing the fluorescence quenching data according to Stern-Volmer equation and Lineweaver-Burk double-reciprocal equation, we found that BSA had reacted with PM-19 and formed a certain new compound. The quenching belonged to static fluorescence quenching. According to Lineweaver-Burk equation, the forming constants of the compound (298 K: 2.68 × 10⁵ L·mol^-1; 304 K: 2.19 × 10⁵ L·mol^-1; 310 K: 1.82 × 105 L·mol^-1) and the thermodynamic parameters (ΔH=-24.72 kJ·mol^-1; ΔS=20.97 J·mol^-1·K^-1 / 20.92 J·mol^-1·K^-1/ 20.97 J·mol^-1·K^-1; ΔG=-30.97 kJ·mol^-1/ -31.08 kJ·mol^-1/-31.22kJ·mol^-1) at the corresponding temperatures were obtained. The latter shows that binding power between them is mainly electrostatic interaction. Based on F?rster′s non-radiation energy transfer mechanism, the binding locality (r=4.14 nm) was calculated between donor and accepter. The effect of PM-19 on the conformation of BSA was also analyzed by synchronous fluorescence spectroscopy.     

Lu(Et2dtc)3(phen)的生成反应焓变、摩尔热容和恒容燃烧能测定

A ternary solid complex Lu(Et₂dtc)₃(phen) has been obtained from the reaction of hydrated lutetium chloride with sodium diethyldithiocarbamate (NaEt₂dtc), and 1,10-phenanthroline (o-phen·H₂O) in absolute ethanol. IR spectrum of the complex indicates that Lu³⁺ binds with sulfur atom in the Na(Et₂dtc)₃ and nitrogen atom in the o-phen. The enthalpy change of liquid-phase reaction of formation of the complex, Δ_rH_m^Ө (l), was determined to be (-32.821 ± 0.147 ) kJ·mol^-1 at 298.15 K by an RD-496 Ⅲ type heat conduction microcalormeter. The enthalpy change of the solid-phase reaction of formation of the complex, Δ_rH_m^Ө (s), was calculated to be (104.160 ± 0.168) kJ · mol^-1 on the basis of an appropriate thermochemistry cycle. The thermodynamics of liquid-phase reaction of formation of the complex was investigated by changing the temperature of liquid-phase reaction. Fundamental parameters, such as the activation enthalpy (ΔH_≠^Ө), the activation entropy (ΔS_≠^Ө), the activation free energy (ΔG_≠^Ө), the apparent reaction rate constant (k), the apparent activation energy (E), the pre-exponential constant (A) and the reaction order (n), were obtained by combination the reaction thermodynamic and kinetic equations with the data of thermokinetic experiments. The molar heat capacity of the complex, c_m, was determined to be (82.23 ± 1.47) J·mol^-1·K^-1 by the same microcalormeter. The constant-volume combustion energy of the complex, Δ_cU, was determined as (-17 898.228 ± 8.59) kJ·mol^-1 by an RBC-Ⅱtype rotating-bomb calorimeter at 298.15 K. Its standard enthalpy of combustion, Δ_cH_m^Ө, and standard enthalpy of formation, Δ_fH_m^Ө, were calculated to be (-17 917.43 ± 8.11) kJ·mol^-1 and (-859.95 ±10.12) kJ·mol^-1, respectively.     

L-苏糖酸锰的制备及标准生成焓

The pink powder of manganese L-threonate was obtained by extracting with alcohol the concentrated solution derived from the reaction between L-threonic acid solution prepared by double decomposition reaction of calcium L-threonate with oxalic acid and superfluous manganese oxide at 80℃ for certain time. The composition of the new compound was determined by chemical and elemental analyses and its formula fits Mn(C₄H₇O₅)₂·H₂O, the IR spectra indicated that Mn²⁺ in the compound coordinates to oxygen atom of the carboxyl group, while the proton of the carboxyl group is dissociated, it was assumed that the coordination number of Mn²⁺ was 4. The results of TG-DTG showed that the compound have fairish stability, the intermediate and final product of the thermal de-composition of the compound are Mn(C₄H₇O₅)₂ and MnO₂, respectively. The constant volume combustion energy of the compound, Δ_cE, were determined by a precise rotating-bomb calorimeter at 298.15K, it was (-3384.30±1.21)kJ·mol^-1, its standard enthalpy of Combustion,Δ_cH_m^?,and standard enthalpy of formation,Δ_fH_m^? , were calculated. They are (-3383.07±1.21)kJ·mol^-1 and (-2 571.68±1.63)kJ·mol^-1, respectively.     

水合偏硼酸钾的热化学研究

Hydrated potassium monoborate(KBO₂·4/3H₂O) was obtained from an aqueous solution in a mole ratio of K₂O∶B₂O₃=2∶1 and characterized by powder X-ray diffraction(XRD)， infrared spectroscopy(FT-IR) and Raman spectroscopy. The enthalpy of solution of hydrated potassium monoborate， KBO₂·4/3H₂O， in approximately 1mol·dm^-3 aqueous hydrochloric acid was determined. Together with the previously determined enthalpies of so-lution of H₃BO₃ in approximately 1mol·dm^-3 HCl(aq) ，and of KCl in aqueous(hydrochloric acid+boric acid)， the standard molar enthalpy of formation of -(1411.11±0.84)kJ·mol^-1 for KBO₂·4/3H₂O was obtained from the standard molar enthalpies of formation of KCl(s)， H₃BO₃(s)， and H₂O(l). The standard molar entropy of formation of -422.94J·K^-1·mol^-1 and standard molar entropy of 163.47J·K^-1·mol^-1 for KBO₂·4/3H₂O were calculated from the thermodynamic relations. A group contribution method is applicable to KBO₂·4/3H₂O.     

N，N，N′，N′-四丁基丙二酰胺从硝酸盐介质中萃取铈(Ⅲ)

Study on the extraction and separation of rare earth with new extractants is important in the rare earth chemistry and nuclear reprocessing. In this work， the extraction of Ce(Ⅲ) with N，N，N′，N′-tetrabutylmalonamide (TBMA) in toluene from nitrate media has been investigated. The effect of the concentration of nitric acid， TBMA and salt-ing-out agent (LiNO₃) and also the temperature on the distribution ratios was examined. The stoichiometries of the extracted complexes were determined to be Ce(NO₃)₃·3TBMA and Ce(NO₃)₃·4TBMA， respectively. The ap-parent extraction constants and the enthalpy of the extraction were calculated based on the extraction data， which are logK_ex1=3.97， logK_ex2=4.75 and Δ_rH_m^?=-31.25kJ·mol^-1， respectively. The IR spectra of the loaded organic phase supported the suggested extraction mechanism.     

复盐法制备无水氯化镁的热解机理及动力学研究

The complex compound (MgCl₂·C₆H₅NH₂·HCl·6H2O) was prepared by reaction of C₆H₅NH₂·HCl with MgCl₂·6H₂O. Reaction mechanism and kinetics of the compounds decomposition were studied by means of the TG-DTA-MS coupling technique and the TG-DTA technique. The results show that there are four steps in the complex′s thermal decomposition, the first two steps correspond to the loss of six crystal waters and the last two steps loss one Aniline hydrochloride. The first three steps belong to the R2 mechanism with 2-dimentional phase boundary reaction as the control step, and the last step belongs to the D3 with 3-dimensional diffusion (sphere Jander equ.) as the control step. The apparent active energy of four steps are, 127.4 kJ·mol^-1, 124.8 kJ·mol^-1, 142.3 kJ·mol^-1 and 329.0 kJ·mol^-1, respectively and the frequency factor are 1.28 × 10¹⁸ s^-1, 7.94 × 10¹⁵ s^-1, 5.98 × 10¹⁶ s^-1 and 4.39 × 10³⁴ s^-1, respectively.     

电解质材料Sr-和Mg-掺杂LaGaO3的制备及性能研究

A dense La_0.8Sr_0.2Ga_0.83Mg_0.17O_2.815 electrolyte in pure perovskite phase was prepared by a polyacrylic acid assisted solid state reaction method, and the effects of La source on the structure and electrochemical performance were also studied. By means of XRD and SEM, the structure of this material was characterized, and the electrochemical properties were studied through AC impedance diagram. The results show that the sample presents a single perovskite-type phase after sintering at 1 450 ℃ and the relative density is 94%. The specimen has the lower activate energy and higher electrical conductivity at 600 ℃. There are two different activation energy at the turning point of 650 ℃, which are 74.6 and 42.4 kJ·mol^-1, respectively. The electrical conductivity is 0.057 S·cm^-1 and 0.017 S·cm^-1 at the temperature of 800 ℃ and 600 ℃, respectively.     

纳米CuO的形貌控制合成及其性能研究

The CuO nanocrystals were prepared by quick-precipitation and hydrolysis method respectively, using Cu(Ac)₂ and NaOH as starting materials. The as-prepared CuO nanocrystals were characterized by XRD, TEM, XPS, UV-Visible absorption spectroscopy and BET. The catalysis of CuO nanocrystals of different morphologies on ammonium perchlorate decomposition was investigated by thermal analysis. Results indicated the variation in temperature for NaOH addition played an important role in the shape of the CuO nanocrystals in precipitation method. Well-dispersed spherical CuO nanocrystals with an average size of 6 nm could be obtained when NaOH was added at 100 ℃ and spindle-shaped CuO nanocrystals exceeding 100 nm in diameter were obtained when NaOH was added at room temperature. Needle-shaped CuO nanocrystals could be prepared by the hydrolysis method, and the presence of small amounts of cetyltrimethylammonium bromide (CTAB) could make needle-shaped CuO well dispersed. The catalytic activity of CuO nanocrystals of different morphologies on ammonium perchlorate decomposition was high. The 2% of spherical CuO nanocrystals could make higher decomposition temperature of ammonium perchlorate decreased to 102 ℃. The exothermic quantity of decomposition was from 590 J·g^-1 up to 1 420 J·g^-1.     

Cu(Ⅱ)-牛磺酸缩水杨醛席夫碱-邻菲咯林三元配合物的合成、晶体结构及性质

The title complex was synthesized by reaction of taurine salicylic schiff base(TSSB), O-phenanthroline(phen) and cupric acetate in water-ethanol solution. The crystal structure was determined by X-ray diffraction method and the chemical formula weight of the complex is 498.00. The crystal structure of the title complex belongs to orthorhombic system with space group Pbcn and cell parameters: a=3.107 2(4) nm, b=1.289 09(18) nm, c= 1.034 78(14) nm; and V=4.144 7(10) nm³, Z=8, D_c=1.596 g·cm^-3, μ=1.197 mm^-1, F(000)=2 048. The compound is an one-dimensional chain complex of infinite length which are connected with hydrogen bonds. The Cu(Ⅱ) was coordinated by two oxygen atoms and three nitrogen while the o atoms of Ac- groups did not participate in the coordination. The Cu(Ⅱ) formed a distorted tetragonal pyramid and the capacities of coordination to Cu(Ⅱ) of atoms was discussed. Besides, the TG-IR of the complex was analyzed. The kinetics of the thermal decomposition reaction of the complex was studied under a non isothermal condition by TG-IR. TG and DTG curves indicate that the complex decomposed in three stages: (?) The kinetic parameters were obtained from the analysis of TG,DTG cures by OZAWA-Flynn-Wall method, and the activation energy and the value of A of the three stages are 74.98 kJ·mol^-1, 286.65 kJ·mol^-1, 87.55 kJ·mol^-1; 9.66×10⁸ s^-1,1.82×10²⁸ s^-1, 3.09×10³s^-1, respectively.     

纳米三氧化二钴低温热容和热力学性质的研究

The isobaric molar heat capacities of nano Co₂O₃ were determined by an adiabatic calorimeter in the temper-ature range from 78 to 350K. No phase transition takes place in this temperature range. The relationship of C_p，m with respect to thermodynamic temperature T was established as C_p，m=-11.998X³-9.6431X²+63.478X+81.291(J·K^-1·mol^-1) ， where X=(T-201.903)/121.535， the correlation coefficient R₂=0.9996. Ac-cording to this relationship and the relationships between thermodynamic functions， the thermodynamic functions of nano Co₂O₃ relative to the standard temperature of 298.15K were derived based on the measured heat capacity data. The average grain size of the studied nano Co₂O₃ sample was determined to be 12nm by TEM.     

Pyrazoles as molecular probes to study the properties of co-crystals by solid state NMR spectroscopy

Equimolar mixtures of 3,5-dimethylpyrazole (1) with four NH-imidazoles (2–5) have been studied by¹³C and ¹⁵N CPMAS NMR and by DSC. In three cases, the solid mixture behaves as the sum of the individual components [imidazole (2), 2-methylimidazole (3) and 2,4(5)-dimethylimidazole (5)]. In one case [4,5-dimethylimidazole (4)], the mixture corresponds to a new species in which the dynamic behavior of1 no longer exists.     

Aqueous p-nitrotoluene oxidation induced with direct glow discharge plasma

A plasma induced degradation process has been studied to treat 4-nitrotoluene (4-NT) present as an aqueous pollutant. The plasma was locally generated from a glow discharge around a tip of a platinum anode in an electrolytic solution. The influence of initial pH and Fe²⁺ on the degradation was examined. Major intermediates resulting from the degradation process were identified. Amongst the aromatic intermediates, p-hydroxybenzoic acid was the predominant degradation product. The formation of oxalic acid, malic acid was also observed. The final products of degradation were NH ₄ ⁺ , NO ₃ ⁻ and CO₂. Based on the analysis of intermediates and the kinetic considerations, the degradation was shown to follow a pseudo-first order reaction hence, a possible reaction pathway was proposed.     

Catalytic air oxidation of manganese in synthetic waters

An attempt was made to study the oxidation of manganese by air in synthetic waters. A series of batch experments were performed at differnet values of concentration, temperature and pH. Unoxidized manganese in the solution was determined by formaldoxime spectrometric method. Results of these studies indicated that the air oxidation of manganese soluble in water can be effectively performed in basic media and that oxidation yield increasedwith an increase in pH and concentration. The yield was very high in the presence of manganese dioxide, sepiolite or clinoptilolite in solution and, the oxidation was almost completed especially at high values of pH and concentration. The reaction was found to be first order with respect to Mn²⁺ with a very low activation energy. A yield of 62% was obtained for the air oxidation of wastewater taken from the treatment plant of Corum Municipality.     

Zur Kenntnis der Reaktionsfähigkeit des Thiomorpholins und alkylsubstituierter Thiomorpholine, 4. Mitt.

Thiomorpholine as well as alkyl substituted thiomorpholines and their Sdioxides, respectively, are transformed into the corresponding N-Aminothiomorpholines by nitrosation (1–5) followed by the reduction with zinc in acetic acid/acetic acid anhydride under simultaneous formation of the corresponding N-acetyl derivates, and hydrolysis by hydrochloric acid (6–9). Examples of this method are described. 4-Aminothiomorpholines and their Sdioxides react with aldehydes or ketones to give azomethines (10–31). Acylation with mono-and dicarbonic acid chlorides leads to the N-acyl derivatives32–44.Mannich condensation is also possible. By oxidation with yellow mercury oxide tetracenes are formed (46–47).

Teil der DissertationM. Schmitz, Techn. Hochschule Aachen, 1975.     

Physico-chemical properties of Chitosan films

Chitosan films obtained by dry phase inversion were prepared from an aqueous solution of chitosan in acetic acid. The films, of thickness less than 20 μm, were transparent, very flexible and had smooth surfaces. Increasing the film thickness induced an increase of the internal tensions and the consequent formation of a rough surface. Structural investigations by X-ray diffraction and Fourier transform IR analysis, showed that the chitosan films, as prepared, are amorphous. Further annealing to evaporate acetic acid and water traces, changed the amorphous phase into a more ordered phase, characterized by diffraction peaks at 2θ values of 9, 17, 20 and 23 degrees. Thermal investigations by TG, DTG, and DTA revealed that the decomposition of the chitosan films as prepared proceeds in two stages, starting from 180°C and 540°C.     

Beiträge zur Chemie der Pyrrolpigmente, 39. Mitt.: Ein Kraftfeldmodell zur konformationsanalytischen Untersuchung von Gallenfarbstoffen

A force field model was designed with respect to the special needs of bile pigments. It is parametrized and tested using partial structures of bile pigments as well as an integral pigment; the solution structures of the molecules were previously deduced using independent experimental methods.

38. Mitt::Falk, H., Schlederer, T., Wolshann, P., Mh. Chem.112, 199 (1981).     

A kinetic method for <Emphasis Type="Italic">para</Emphasis>-nitrophenol determination based on its inhibitory effect on the catalatic reaction of catalase

The inhibitory effect of para-nitrophenol on the catalytic reaction of catalase was investigated. Michaelis-Menten kinetic parameters were determined from Lineweaver-Burk plots obtained in the absence or in the presence of the inhibitor. The inhibitor pattern, revealed by the Lineweaver-Burk plots, suggested a fully mixed inhibition mechanism. Spectrophotometric monitoring of the indicator reaction: in conjunction with initial rate measurements was employed for the kinetic determination of the inhibitor. Calibration plots of initial rate vs. para-nitrophenol concentration were linear in the concentration range 0.9·10⁻⁵–2.5·10⁻⁵ mol/L and the detection limit was 3·10⁻⁶ mol/L (417 μg/L) para-nitrophenol. Interferences from other phenolic compounds like orto-cresole, meta-and orto-nitrophenol were observed.     

Polarographische Untersuchung der Kinetik der Polymerisation von Methylvinylketon

The homogeneous polymerization of methyl-vinyl ketone in diluted methanol solutions in presence of proton donors is studied using the polarographic method. The effect of the cation of the indifferent electrolyte is investigated as well as the influence of small quantities of H₂O. Suggestions were made about the possible mechanisms of these influences in the general scheme of the process proposed byHolleck et al.

     

Aminoalkoholester von Hydroxyboranen,IX Salicylamid-Bor-Mannichbasen als potentielle Antitumorwirkstoffe

A synthesis of new boron containingMannich bases of salicylamide by reaction of salicylamide, formaldehyde and boron-heterocycles is reported.

VIII. Mitteilung:Stump, R. K., Zimmerman jr., H. K., Schleppnik, A. A., Gutsche, C. D., Liebigs Ann. Chem.667, 18 (1963).     

A unique geometry of the active site of angiotensin-converting enzyme consistent with structure-activity studies

Summary Previous structure-activity studies of captopril and related active angiotensin-converting enzyme (ACE) inhibitors have led to the conclusion that the basic structural requirements for inhibition of ACE involve (a) a terminal carboxyl group; (b) an amido carbonyl group; and (c) different types of effective zinc (Zn) ligand functional groups. Such structural requirements common to a set of compounds acting at the same receptor have been used to define a pharmacophoric pattern of atoms or groups of atoms mutually oriented in space that is necessary for ACE inhibition from a stereochemical point of view. A unique pharmacophore model (within the resolution of approximately 0.15 Å) was observed using a method for systematic search of the conformational hyperspace available to the 28 structurally different molecules under study. The method does not assume a common molecular framework, and, therefore, allows comparison of different compounds that is independent of their absolute orientation.Consequently, by placing the carboxyl binding group, the binding site for amido carbonyl, and the Zn atom site in positions determined by ideal binding geometry with the inhibitors' functional groups, it was possible to clearly specify a geometry for the active site of ACE.