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1.
在乙腈溶液中合成了标题化合物,(C(34)H(54)N2O10)[Eu(NO3)5](C(34)H(52)H2O(10)=1,2-二(2,3-苯并-10-氮杂-15-冠-5-N-乙氧基)乙烷)并用X射线衍射分析测定了它的结构。该晶体属单斜晶系,P21/c空间群,晶胞参数:a=1.1801(2)nm,b=2.3560(5)nm,c=1.7025(3)nm,β=99.67(3)°。V=4.6662(16)nm',Z=4,Dc=1.581g·cm(-3)。Eu(3 )与5个NO3的10个O配位。大环化合物上无论是O还是N都未与Eu(3 )成键。  相似文献   

2.
合成了[Y(NTO)2NO3(H2O)5]·2H2O(NTO为3-硝基-1,2,4-三唑-5-酮),并测定了晶体结构,晶体属单斜晶系,空间群Cm,晶胞参数:a=0.6773(2)urn,b=20866(2)um,c=0.6551(1)um;β=102.98(2)°,V=0.9021(1)um3,Z=2,DC=1.970g·cm-3,μ=33.49cm-1,F(000)=54O,R=0.032.中心Y(Ⅲ)与2个NTO的羰基氧原子、1个NO3的1个氧原子及5个水分子的氧原子配位,形成畸变的十二面体.Y-O键长在0.2283~0.2478um之间.  相似文献   

3.
研究了碱式笼形聚偕胺树脂(BCAO)吸附Pd(Ⅱ)的行为.溶液pH值对吸附容量有重要的影响.在一定条件下,BCAO在中性溶液中吸附Pd(Ⅱ)的量是酸性溶液中的一倍以上,但提高溶液的酸性有利于从稀溶液中回收钯.Pd(Ⅱ)在盐酸溶液中显H_2PdCI_4结构.吸附结果生成AO-Pd络合物.当溶液被碱中和至近中性时,Pd(Ⅱ)以Pd~(2+)和[Pd(OH)_2CI_2]2-的形式存在,吸附过程中先后生成AO-Pd,AO-Pd_2和AO_2-Pd_3先等不同组成的给合物.由于AO与Pd(Ⅲ)之间较大的电位差,部分Pd(Ⅱ)被还原成Pd(0),并汇聚在BCAO表面上.  相似文献   

4.
王大文  钟顺和 《催化学报》2003,24(9):705-710
 用溶胶-凝胶法以磷钼酸(MPA)的铜盐溶液水解钛酸四丁酯制备了CuPMo/TiO2催化剂,并用ICP,XRD,TG-DTA,IR,TPD-MS和微反技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化性能.结果表明:杂多钼酸盐与TiO2表面通过O2-桥发生键联.在623K下,杂多阴离子仍保持其原有的Keggin结构;CO2在Lewis酸位Cu(Ⅱ)和Lewis碱位Cu-O-Mo桥氧的协同作用下形成卧式吸附态Cu(Ⅱ)←O-(CO)←(O--Cu);丙烯以分子吸附态在催化剂上吸附;在空速1500h-1,压力1MPa和温度563K的反应条件下,丙烯的转化率为4.2%,甲基丙烯酸的选择性为96%.  相似文献   

5.
环糊精接枝聚硅氧烷气相色谱固定相的手性拆分性能   总被引:3,自引:2,他引:3  
用环糊精接枝聚硅氧烷(二环[2,6-二-O-戊基-3-O-己烯基(-5)]五环[2,6-二-O-戊基-3-O-甲基-β-CD聚硅氧烷]作气相色谱固定相成功地拆分具有两个手性中心的物质--2,6-二乙酰氧基庚烷;考察了色谱条件对手性拆分的影响。  相似文献   

6.
二苯并噻吩在CoMo/γ-Al2O3催化剂上的分散及吸附   总被引:1,自引:0,他引:1  
 二苯并噻吩(DBT)在80℃下与CoMo/γ-Al2O3催化剂混合并放置24h,即可在催化剂表面发生自发单层分散.通过XRD测定出其分散阈值为0.15g/g,大于计算值0.12g/g(平躺吸附密置单层分散容量),排除实验误差后可以推测DBT在CoMo/γ-Al2O3表面存在通过硫原子的端链吸附.FT-IR和LRS的分析结果与上述推测相一致,说明DBT可能通过硫原子吸附在CoMo/γ-Al2O3表面的酸中心上.  相似文献   

7.
活性炭自溶液吸附锌(II)离子及其配合物   总被引:10,自引:0,他引:10  
近年来,有人提出通过表面处理提高活性炭表面电荷,加强对无机离子吸附力等观点,但活性炭对无机离子的吸附活性点,表面含氧基团及配体对吸附的影响等重要问题仍众说纷经[1-4]为此,本文提出用氧化一负离子化法处理活性炭,以表面酸度表征表面含氧基团的量,探讨活性炭对Zn(Ⅱ)及其配合物的吸附特性.1试验(1)试验材料活性发由北京光华木材厂出品,分析纯.过20-30目,BET法测得比表面为1316m2·g-1.在2.5×10-2mlo·dm-3的NaNO3中,测得等电点pHIEP为7.75[5],元素含量(质量分数)为C(83.9%),N(0.07%),H(1…  相似文献   

8.
柱撑阴离子粘土的合成、表征及催化性能研究(Ⅴ)   总被引:1,自引:0,他引:1  
近年来,同多酸和杂多酸型层往化合物作为新型微孔催化剂,在固体无机合成化学和多酸催化化学等领域引起人们的关注[1-3].Pinnavaia[3]等人首先将同多阴离子发通过与Zn2AlNO3进行离子交换反应,制备了通道高度为0.72urn的新型无机层柱化合物Zn2Al-V10O28.并发现它在液·固相体系中,对异丙醇光氧化成丙酮的反应具有较高活性与选择性.最近,我们采用类似的方法制备了单取代和三取代型Keggin结构杂多阴离子XW11ZO39(H2O)n-[4]和XW9Z3O37(H2O)[5](分别缩写成XW11Z和XW9Z3)柱撑的ZnAl层柱双羟基化合物Zn2Al-HPOMs(H…  相似文献   

9.
1引言析相光度法具有富集和分离作用,已用于一些微量元素测定.本文运用卡尔曼波波递推法,以2-(5一摸一2一毗峻仍氛)七一二乙氨基采酚(5-Br-PADAP)为显色剂,研究了Zn、Mn、Cd──5-Br-PADAP-TritonX-100析相显色体系,建立了同时测定微量锌锰钢的析相光度法。应用于水样中微量锌锰镉的测定,结果满意。2实验部分2.1主要试剂和仪器锌锰镉标准溶液:2mg/L工作溶液,5-Br-PADAP溶液:0.05%乙醇溶液;H3BO3NaOH缓冲溶液pH9.0.TritonX-100溶液:20%水溶液;UV-260型紫外可见分光光度计;pHS-2型酸度计,…  相似文献   

10.
基于秋加耶夫(Chugaev)反应,采用分光光度法测定银杏叶中聚异戊烯醇化合物含量;以ZnCl2的CH3COOH溶液-CH3COCl(体积比10:1)为显色剂,通过在388nm处测定溶液的吸光度确定聚异戊烯醇化合物的含量;聚异戊烯醇化合物在0.103-2.060mg范围内与吸光度值有良好线性关系;方法的回收率为97%-103%,相对标准偏差(RSD)为5.7%;方法简便、快速。  相似文献   

11.
The protection power of the cationic surfactant decylammonium acetate (DAA) in seawater has been studied to define the perfect conditions have to be found for using it as a corrosion inhibitor for copper surface. The adsorption isotherm of this surfactant on copper surface has been determined at different interval times at 30°C. The given isotherms have, in general, similar shapes exhibiting a Languimirian L-shape. The corrosion measurement has been determined according to weight loss method. The study declines that cationic DAA, in seawater, protects well the copper surface against corrosion when added with low concentrations, while high concentrations show bad inhibition efficiency. ICP spectroscopic analysis assures this result where high Cu% has been obtained in the presence of high DAA concentration.  相似文献   

12.
测定了CAB-O-SIL在290.7K和304.2K时自水和1mol/LNaCl溶液中吸附非离子表面活性剂TritonX-100(TX100)的吸附等温线。结果表明,吸附量随温度升高而增加。NaCl的存在也使吸附量增加。运用生成表面胶团的吸附理论处理了实验结果,求得了表面胶团化的平衡常数、表面胶团的平均聚集数、临界表面胶团浓度和表面胶团化的标准热力学函数。实验表明,随TX100浓度的增大,CAB-O-SIL悬浮液稳定性出现不规则的变化。加入NaCl的效应是使悬浮液的稳定性下降和促进表面胶团的形成。结合吸附研究结果,提出了一个涉及表面胶团的颗粒相互作用模型,合理地解释了悬浮液稳定性的实验结果。  相似文献   

13.
In situ surface enhanced infrared absorption spectroscopy (SEIRAS) with an attenuated total reflection (ATR) configuration has been used to monitor the adsorption kinetics of bovine hemoglobin (BHb) on a Au nanoparticle (NP) film. The IR absorbance for BHb molecules on a gold nanoparticle film deposited on a Si hemispherical optical window is about 58 times higher than that on a bare Si optical window and the detection sensitivity has been improved by 3 orders of magnitude. From the IR signal as a function of adsorption time, the adsorption kinetics and thermodynamics can be explored in situ. It is found that both the electrostatic interaction and the coordination bonds between BHb residues and Au NP film surface affect the adsorption kinetics. The maximum adsorption can be obtained in solution pH 7.0 (close to the isoelectric point of the protein) due to the electrostatic interaction among proteins. In addition, the isotherm of BHb adsorption follows well the Freundlich adsorption model.  相似文献   

14.
提出一种极谱免疫法测定人血清补体活性的新方法,利用补体作用下的免疫溶血反应释放出的具有拟过氧化物酶活性的血红蛋白,催化邻苯二胺和H2O2的反应,通过酶促产物2,2′-二氨基偶氮苯的极谱检测来确定补体的活性。测定范围为0.10-1.00CH50unit/mL,检出限为0.08CH50unit/mL。灵敏度比分光光度法高10倍,一次可分析25份血样,已用于正常人和病人血清中补体活性的测定。  相似文献   

15.
Adsorption behavior of selected monosaccharides onto an alumina interface   总被引:2,自引:0,他引:2  
The adsorption of glucose and fructose from their aqueous solutions onto an alumina interface has been carried out spectrophotometrically at room temperature. The adsorption isotherms are characterized as typical L-type and an adsorption mechanism on the basis of dipolar interactions has been suggested. In addition to this, a partial role of metal-saccharide interactions as found in organometallic complexes (OMCs) for the observed adsorption cannot be ruled out. Various kinetic and thermodynamic parameters of the adsorption process have been evaluated. The effects of variation in experimental conditions of the system have also been investigated. The adsorption exhibited a typical response to the pH effect and maximum adsorption was found near the isoelectric point of alumina (pH 9.0). The anionic addition to the suspension affects the adsorbed amount and Cl(-), SO(4)(2-), and PO(4)(3-) affect the adsorption quantitatively. The addition of similar concentration of cations was found to reduce the adsorbed amount. The presence of cationic and anionic detergents was found to influence both the adsorbed amount and the adsorption rate. The temperature was found to have an inverse effect on adsorption. Adsorptive kinetic parameters have revealed that fructose tends to be a better adsorbate than glucose. This is found to be consistent with the chelation behaviour of monosaccharides as found in the OMC of monosaccharides. The thermodynamics of the adsorption model indicates its spontaneous and exothermic nature. The negative values of entropy are an indication of the probability of a favorable nature of adsorption.  相似文献   

16.
Structure and bonding characteristics, and gas phase stepwise basicities of proposed multivalent bases 1,3,5,7-tetraazatricyclo[3.3.1.1(3,7)]decane, 1,3,5,7,9,10-hexaazatricyclo[3.3.1.1(3,7)]decane and tricyclo[3.3.1.1(3,7)]azadecane, named and abbreviated here respectively as tetra-aza-adamantane (TAA), hexa-aza-adamantane (HAA) and deca-aza-adamantane (DAA), have been studied using B3LYP/6-311++G** method. Effects of protonation on the bond lengths and angles, and atomic charges, and on their correlations are studied in detail. Results show that the most affected characteristics by protonation are the N–H bond lengths and the charge of the hydrogen atoms. It is found, interestingly, that in the protonation of DAA, electric charges of the unprotonated nitrogen atoms are increased more than that of the protonated nitrogen atoms. Because of very small effects of protonation on the skeletal C–N and N–N bond lengths, it can be said that the aza-adamantane cage volume is not changed significantly upon protonation. The protonation energies approve multivalent nature of these bases with the order of TAA ≈ HAA > DAA. Different isomers for the unprotonated and protonated HAA and DAA are also studied.  相似文献   

17.
Linear copolymers from N-isopropylacrylamide(NIPA),acrylic acid(AA)and diacetone acrylamide(DAA)have been prepared. The effect of composition,ionic strength and pH on their lower critical solution temperature(LCST)has been investigated.  相似文献   

18.
In the present study, a hydrophobic zeolite was used as an adsorbent for the adsorption of polyethylene glycol (PEG) in water solution and electroplating solution at 25 degrees C. The adsorption capacities were determined through the adsorption isotherms in a thermostated shaker. The rate of adsorption, on the other hand, was investigated in a batch adsorber under controlled process parameters such as initial PEG concentration (30, 70, 110, 150, 200, and 300 mg x dm(-3)), agitation speed (200, 800, and 1000 rpm), and adsorbent particle size (0.72, 1.44, and 2.03 mm). A batch kinetic model, according to a pseudo-second-order mechanism, has been tested to predict the rate constant of adsorption, equilibrium adsorption capacity, time of half-adsorption, and equilibrium concentration by the fitting of the experimental data. The results of the adsorption isotherm and kinetic studies show that the adsorption process can well be described with the Langmuir and Freundlich models and the pseudo-second-order equation, respectively. Comparing the values of adsorption parameters of PEG in water solution and electroplating solution, there are no significant differences. In addition, the effective diffusion coefficient of the PEG molecule in the microporous adsorbent has been estimated at about 3.20 x 10(-8) cm(2)s(-1) based on the restrictive diffusion model.  相似文献   

19.
Ordered mesoporous carbons (OMCs) with varying pore sizes were prepared using ordered mesoporous silica SBA-15 as hard templates. The OMCs possess abundant mesopores with narrow pore size distribution, on which the adsorption behavior of bulky molecules of nonylphenol ethoxylate (NPE) were investigated. The isotherms of NPE on OMCs can be fitted by Langmuir adsorption model, evidenced by the adsorption data. The surface area of the pores larger than 1.5 nm is a crucial factor to the adsorption capacity of NPE, whereas the most probable pore diameter of OMCs is crucial to the adsorption rate of NPE. The adsorption temperature has more significant effects on adsorption rate than the adsorption capacity. Theoretical studies show that the adsorption kinetics of NPE on OMCs can be depicted with the pseudo-second-order kinetic model. In addition, thermodynamic parameters of adsorption were evaluated based on the equilibrium constants related to the equilibrium of adsorption at different temperatures.  相似文献   

20.
The adsorption of humic acid (HA) onto highly ordered pyrolytic graphite (HOPG) surfaces at different concentrations has been studied by atomic force microscopy. When HA concentration was increased from 10 to 1,000 mg/L, HA can sequentially form spherical particles, layered structures, and connected blocks on HOPG surfaces. The findings of the layer structures and small amount of fine chains have been verified and discussed. When HA was acidified by addition of acetic acid, it changed into small rigid particles. These results indicated that HA can be considered as supramolecular associations of self-assembling heterogeneous and relatively small molecules, and a small amount of polymers. The present results are important for understanding HA molecular structures and their adsorption characteristic on carbonaceous surfaces.  相似文献   

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