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71.
72.
配体的空间构型及疏水性对钌(Ⅱ)多吡啶配合物与DNA作用的影响 总被引:19,自引:2,他引:19
合成了4-氰基苯基咪唑并[5,6-f]邻菲咯啉(CYIP)和2-羧基苯基咪唑并[5, 6-f]邻菲咯啉(COIP)两种新配体及它们的钌混配配合物[Ru(bpy)2CYIP](ClO4)2 ·H2O(Rul)(bpy=2,2′-联吡啶),[Ru(phen)2CYIP](ClO4)2·H2O(Ru2) (phen=1,10-邻菲咯啉),[Ru(bpy)2COIP](ClO4)2·3H2O(Ru3)和[Ru(phen)2COIP] (ClO4)2·H2O(Ru4),并用红外光谱、紫外光谱、核磁和质谱对它们进行了表征。 通过循环伏安法研究了这些配合物的电化学性质。采用电子吸收光谱、稳态荧光、 圆二色谱和粘度测定研究了配合物与小牛胸腺DNA的相互作用。结果表明配合物 Rul和Ru2通过CYIP配体以插入的方式与DNA结合,而配合物Ru3和Ru4则通过COIP配 体以部分插入的方式与DNA结合。 相似文献
73.
IntroductionItiswellknownthatyttriumcanbeusedinmanyfields ,suchasmetallurgy ,ceramics ,lasersandelectron ics ,especiallyinfluorescentmaterialswhoseneedforhighpurityyttriumoxideisincreasing .InChina ,there sourceofyttriumisrich ,andthehighpureyttriumisbe ingo… 相似文献
74.
Cis-dioxo-metal complex ( NH3CH2CH2NH2 ) 2.5 [ Mo0.5^(V)W0.5^(VI)O2 ( OC6H4O ) 2] 1 was obtained by the reaction of tetra-butyl ammonium hexamolybdotungstate with 1, 2-dihydroxybenzene in the mixed solvent of CH3OH, CH3CN and ethylenediamine,and characterized by X-ray diffraction, UV-vis and EPR analysis. Compared with its analogous complexes (NH3CH2CH2NH2)3[Mo^(V)O2(OC6H40)2] 2 and (NH3CH2CH2NH2)2[W^(VI)O2(OC6H4O)2] 3, the results show that tungsten(VI) is less active in redox than molybdenum (VI) and that the change of the valence induced by substitution of W(VI) for Mo(V) in EMO2(OC6H40)2]n- does not influence the coordination geometry of the complex anion in which the metal center exhibits distorted octahedral coordination with cis-dioxo catechol. The responses to EPR of complexes 1 and 2 are active but complex 3 is silent,and the UV-vis spectra exhibited by the three complexes are obvious different because of the different electronic configuration between the central Mo(V) and W(VI) ions in the complexes.It is noteworthy that complexes 1 and 2 have the similar EPR signal to flavoenzyme, suggesting that the three complexes have the same coordination geometry feature with the co-factor of flavoenzyme. 相似文献
75.
Determination of in vitro permeability of drug candidates through a caco-2 cell monolayer by liquid chromatography/tandem mass spectrometry 总被引:6,自引:0,他引:6
Studying the permeability of compounds across a Caco-2 cell monolayer is an established in vitro model to screen for oral absorption and to evaluate the mechanism of transport. This assay can also be used to evaluate compounds as potential P-glycoprotein substrates and/or inhibitors. The traditional methods of sample analysis (high-performance liquid chromatography (HPLC) with a UV or fluorescence detector) limit the throughput and sensitivity of this assay. Data are presented here describing the use of liquid chromatography/tandem mass spectrometry (LC/MS/MS) for the analysis of samples derived from the Caco-2 cell studies. During the analysis an automatic switching valve was used to divert the flow from the HPLC column to waste for the first minute, preventing the early eluting salts from entering and contaminating the LC/MS interface. This approach allows the rapid and accurate determination of drug transport across the Caco-2 cell monolayer. The high sensitivity and specificity of LC/MS/MS make this technique an ideal candidate for the low concentration and high throughput routine analysis of Caco-2 cell solutions, especially if multiple compounds are administered and analyzed simultaneously. Thus, the use of LC/MS/MS will increase the value of the Caco-2 cell assay as an in vitro screening tool. 相似文献
76.
Interaction between octahedrally coordinated Nd3+ and Yd3+ in Cs2NaNd0,4Yb0,6Cl6 reduces the Nd3+ luminescence lifetime by roughly two orders of magnitude with respect to that found in Cs2NaNdCl6– · – Analysis of low temperature absorption and emission spectra reveals that the nonradiative Nd3+–Yb3+ energy transfer has to be assisted by lattice phonon emission, nevertheless the rate of the transfer is high in the 4–300 K temperature region and attains 5.8×105s-1 at room temperature. A phase transition of Cs2NaNd0,4Yb0,6Cl6 between 12 and 13 K is evidenced by abrupt change of both the spectra and lifetimes of Yb3+. Reduction of Yb3+ lifetime from 5.3 ms to 150 μs is at the transition from low symmetry phase to high symmetry phase is supposed to be associated with a three ion interaction which occurs in ordered lattice and disappears in low temperature disordered structure. 相似文献
77.
Ya-Guang Chen Fan-Xia Meng Hai-Jun Pang Dong-Mei Shi Yu Sun 《Journal of Cluster Science》2007,18(2):396-405
A novel uranyl complex with dimeric lacunary polyoxoanion like open-mouthed clam, Na5[(A-α-SiW9O33H3)2K{UO2(H2O)}2], was prepared and characterized by elemental analysis, infrared and ultraviolet–visible spectroscopy and single crystal
X-ray diffraction. In the anion, two A-α-SiW9O3410− groups share two terminal oxygen atoms Od′ derived from removal of three corner-shared W atoms from saturated α-Keggin anion, forming a dimeric anion with an open
mouth in which potassium ion and uranyl ions are coordinated. Uranium atom adopts a pentagonal bipyramidal geometry. The coordinating
anions are linked by sodium ions via coordination of terminal or bridging oxygen atoms, forming two-dimensional layer arrangement.
Between the layers are the hydrogen bonds from which a supramolecular architecture is created. UV–VIS spectrum gives W–O and
U–O charge transfer transitions at 230–265 and 432 nm, showing the change of geometry of the polyanion and weakening of the
U–O bonds of the uranyl cation.
Electronic supplementary material The online version of this article () contains supplementary material, which is available to authorized users. 相似文献
78.
79.
Y2O3和CeO2复合掺杂ZrO2纳米晶的制备与表征 总被引:2,自引:0,他引:2
以ZrOCl2.8H2O,Y2O3,Ce(NO3)3.5.5H2O为原料,NH3.H2O作沉淀剂,少量表面活性剂PE作分散剂,采用反向共沉淀-喷雾干燥法,结合物理、化学分散技术,成功地制备了Y2O3,CeO2复合掺杂ZrO2纳米粉末。通过DSC-TG,XRD,XPS,BET和SEM等方法对所制得粉末进行了表征。结果表明:以Ce0.1Y0.1Zr0.8O1.95化学计量比制备的多元氢氧化物胶体经过喷雾干燥处理后,在500℃基本完成水合氧化物的分解,577℃附近完成由非晶相向立方相的转变;经过580-1000℃煅烧后,CeO2和Y2O3已经完全固溶到ZrO2中,形成类质同相体,该粉末系列均属于立方相萤石结构;掺杂进入ZrO2晶格中的Ce呈+4价形式存在;比表面积由22.0 m^2.g^-1(580℃煅烧)减至4.97 m^2.g^-1(1000℃煅烧);SEM结果显示800℃煅烧的该粉末颗粒尺寸分布均匀,多呈类球状,且粒径在50-80 nm。 相似文献
80.
An eficient liquid-phase synthesis of isoxazolines through a 1,3-dipolar cycloaddition is described.Soluble polymer-supported acrylate reacted with nitrile oxides generated in-situ,followed by cleavage from the support giving corresponding isoxazolines in high yields and excellent purities. 相似文献