5,7,8位取代的喹诺酮类化合物定量构效关系的量子化学研究

５，７，８位取代的喹诺酮类化合物定量构效关系的量子化学研究俞庆森，朱龙观，林瑞森，蔡国强（浙江大学化学系杭州３１００２７）关键词：氟喹喏酮类，定量构效关系，ＣＮＤＯ／２氟喹诺酮类是一类重要的抗感染化疗药物￣［１］，近十年对其研究进展神速￣［２］，结构...     

Adsorption, desorption and activities of acid phosphatase on various colloidal particles from an Ultisol

Adsorption, desorption and activity of acid phosphatase on various soil colloidal particles and pure clay minerals were studied. Higher adsorption amounts and low percentage of desorption of acid phosphatase were found on fine soil clays (<0.2 μm). Electrostatic force and ligand exchange are the major driving forces that are involved in the adsorption of enzymes on soil clays. More enzyme molecules were adsorbed on soil clays in the presence of organic components. However, enzymes on organic clays were more easily released. One-third of the enzyme on goethite was adsorbed via ligand exchange process. Some other interactions, such as van der Waals force, hydrophobic force and hydrogen bonding may be more important in the adsorption of enzyme on kaolinite and the enzyme in this system cannot be easily removed. Coarse clays (0.2–2 μm) and inorganic soil clays had higher affinities for enzyme molecules than fine clays and organic clays, respectively. The activity of enzyme bound on soil clays was inhibited and the thermal stability was increased in the presence of organic matter. Data obtained in this study are helpful for a better understanding of the interactions of enzymes with inorganic and organic constituents in soil and associated environments.     

One-step Beckmann Rearrangement from Ketones and Hydroxylamine in Dry Media under Microwave Irradiation

TheBeckInannrearrangement,theacid-mediatedisomerizationofoximestoamides,wasfirstdiscoveredinl886l.Asoneoftheoldestandmostfamiliartransformationsinorganicchemistry,ithasbeenwidelystudiedandagreatvarietyofmethodstoconductthistfansformationhavebeenreported'.However,mostofthesemethodswerecarriedoutbyusingalargeamountofsolventswithlongreactiontime.Whatismore,thepriorpreparationofthecorrespondingketoximesisusuallyrequired,whichmakestheseprocessesinconvenientandlessattractive.Bytakingadvantageofboth…     

三价铬与丙二酸形成的配合物的热解过程研究

利用热重分析及原位红光谱等方法，定性，定量地研究了三价铬和丙二酸形成的配合物［Ｃｒ（Ｃ３Ｈ２Ｏ４）（Ｈ２Ｏ）４］［Ｃｒ（Ｃ３Ｏ４）２（Ｈ２Ｏ２）］．４Ｈ２Ｏ的热解过程，提出了室温至４００℃下的详细热解途径。基于多种实验结果，分析了螯合物中六员环的化学断裂方式，并由配合物的快原子轰击质谱（ＦＡＢ－ＭＳ）加以佐证。     

Antimony speciation by inductively coupled plasma mass spectrometry using solid phase extraction cartridges

A novel and simple method for inorganic antimony speciation is described based on selective solid phase extraction (SPE) separation of antimony(III) and highly sensitive inductively coupled plasma mass spectrometric (ICP-MS) detection of total antimony and antimony(V) in the aqueous phase of the sample. Non-polar SPE cartridges, such as the Isolute silica-based octyl (C8) sorbent-containing cartridge, selectively retained the Sb(III) complex with ammonium pyrrolidine dithiocarbamate (APDC), while the uncomplexed Sb(V) remained as a free species in the solution and passed through the cartridge. The Sb(III) concentration was calculated as the difference between total antimony and Sb(V) concentrations. The detection limit was 1 ng L(-1) antimony. Factors affecting the separation and detection of antimony species were investigated. Acidification of samples led to partial or complete retention of Sb(V) on C8 cartridge. Foreign ions tending to complex with Sb(III) or APDC did not interfere with the retention behavior of the Sb(III)-APDC complex. This method has been successfully applied to antimony speciation of various types of water samples.     

Quantum scattering LCAC-SW theory studies on reaction probabilities of three-dimensional H + H2 (v, j) → H2 (v′, j′) + H reaction

Upon the Liu, Siegbahn, Truhlar, Horowitz (LSTH) potential energy surface, the reaction probabilities of the three-dimensional (3-D) state-to-state H + H₂ (v, j) →H ₂(v′, j′) + H reaction are calculated with the linear combination of arrangement channels-scattering wavefunction (LCAC-SW) method. In the calculation, the vibration function of H₂ and the radial propagating wave functions are expanded by the real Gauss functions. The calculated threshold energy and the resonating structure are consistent with the results of the accurate quantum scattering calculations, which shows the accuration, simplicity and practicability of the LCAC-SW method. Project supported by the National Natural Science Fondation of China and the Doctoral Foundation of the State Education Commission of China.     

A quantum scattering study of collinear state-testate reaction probabilities for the F + H2(v) → HF(v') + H system

A new quantum scattering approach (linear combination of arrangement channels-scattering wavefunction, LCAC-SW) proposed by Deng and his co-workers is used to calculate collinear state-to-state reaction probabilities for the F + H₂(v) → HF(v') + H system. Several interesting problems such M threshold energy, compound states and enhance by translational energy of the reactants and the vibration excitation of products are discussed and they are compared with other theoretical investigations reported in the literature. It is shown that the LCAC-SW approach is the successful one of quantum scattering methods.     

钼铁混合金属原子簇化合物[(η5-C5H5)4Mo4Fe2(μ3-S)5(CO)5]的合成和结构

(η~5-C_5H_5)_4Mo_4Fe_2(μ_3-S)_5(CO)_5 have been prepared from (η~5-C_5H_5)_2Mo_2(CO)_6 and Fe_8S_2(CO)_9 under toluene reflux for 14.5 hrs.The crystal and molecular structures of (η~5-C_5H_5)_4Mo_4Fe_2(μ_3-S)_5(CO)_5 were studied by X-ray structure analysis. The Crystallographic data are as follows: monoclinic, space group P2_1/n, unit cell: a=1.0589(4), b=1.7260(4), c=1.8963(4) nm, β=101.44(2)°, V=3.3967 nm, D_c=2.06 gcm~(-3) for Z=4, X-ray data were obtained over the range of 2°<2θ<50° via the ω-2θ scan mode with MoKα radiation on an Enraf-Nonius CAD4 diffractometer. The structure was solved by direct method (MULTAN) and refined by full matrix least-squares techniques for 3993 reflections with I>2σ(I), The final R=0.081. Figure 1 illustrates the configuration of the molecule (η~5-C_5H_5)_4Mo_4Fe_2(μ_3-S)_5(CO)_5, composing of a cubane-like (FeMo_3S_4) core and a trigonal pyramid (MoFe_2S) core, which linked by sharing Fe(1) atom.     

铜电极表面的电致发光法现场测试

采用电致发光等方法, 初步探讨了铜电极在0.25 mol·L~(-1)Na_2S_2O_8+1.25 mol·L~(-1)NaOH溶液中的电致发光特性及其相关性能, 给出了电致发光法现场测试铜电极表面性质的初步结果。     

结合三维静电势参数研究二取代苯的定量结构－疏水性关系

对含有常见取代基的92个二取代苯化合物进行了结构优化和静电势及其导出参数的计算,运用多元线性回归方法对化合物的疏水常数与分子的结构参数进行了关联.结果表明,分子表面负静电势的加和ΣV－S、分子空间内最负的静电势Vmin、表面最大静电势Vs,max以及分子体积V、极性表面积APS和分子的偶极密度μ/V这六个参数,可以很好地用于表达这些化合物疏水性与分子结构间的定量关系,而不用具体考虑分子中极性基团间的相互作用.用建立起来的QSPR(quantitative structure-property relationship)关系式对111个类似化合物的疏水性进行了预测,获得了满意的结果.