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101.
二甲基甲酰胺中四种钕盐的电导 总被引:3,自引:0,他引:3
通过电导测量研究了四种钕盐:Nd(CF3SO3)3、Nd(ClO4)3、Nd(NO3)3和NdCl3在极性非质子溶剂DMF中的电导性质.利用线性拟合方法求得在25 ℃下Nd(CF3SO3)3和Nd(ClO4)3的极限摩尔电导率分别为278.8和 280.7 S•cm2•mol-1.用间接方法求得Nd(NO3)3 与NdCl3 的极限摩尔电导率分别为297.2和287.3 S•cm2 •mol-1.在25~65 ℃温度范围内,Nd(CF3SO3)3和Nd(ClO4)3的电导率随温度呈线性变化. Nd(NO3)3和NdCl3的电导行为表现出明显的离子缔合. 相似文献
102.
In aqueous H2SO4, Ce(IV) ion oxidizes rapidly Arnold's base((p-Me2NC6H4)2CH2, Ar2CH2) to the protonated species of Michler's hydrol((p-Me2NC6H4)2CHOH, Ar2CHOH) and Michler's hydrol blue((p-Me2NC6H4)2CH+, Ar2CH+). With Ar2CH2 in excess, the rate law of the Ce(IV)-Ar2CH2 reaction in 0.100 M H2SO4 is expressed -d[Ce(IV)]/dt = kapp[Ar2CH2]0[Ce(IV)] with kapp = 199 ± 8M?1s?1 at25°C. When the consumption of Ce(IV) ion is nearly complete, the characteristic blue color of Ar2CH+ ion starts to appear; later it fades relatively slowly. The electron transfer of this reaction takes place on the nitrogen atom rather than on the methylene carbon atom. The dissociation of the binuclear complex [Ce(III)ArCHAr-Ce(III)] is responsible for the appearance of the Ar2CH+ dye whereas the protonation reaction causes the dye to fade. In highly acidic solution, the rate law of the protonation reaction of Michler's hydrol blue is -d[Ar2CH+]/dt = kobs[Ar2CH+] where Kobs = ((ac + 1)[H*] + bc[H+]2)/(a + b[H+]) (in HClO4) and kobs= ((ac + 1 + e[HSO4?])[H+] + bc[H+]2 + d[HSO4?] + q[HSO4?]2/[H+])/(a + b[H+] + f[HSO4?] + g[HSO4?]/[H+]) (in H2SO4), and at 25°C and μ = 0.1 M, a = 0.0870 M s, b = 0.655 s, c = 0.202 M?1s?1, d = 0.110, e = 0.0070 M?1, f = 0.156 s, g = 0.156 s, and q = 0.124. In highly basic solution, the rate law of the hydroxylation reaction of Michler's hydrol blue is -d[Ar2CH+]/dt = kOH[OH?]0[Ar2CH+] with kOH = 174 ± 1 M?1s?1 at 25°C and μ = 0.1 M. The protonation reaction of Michler's hydrol blue takes place predominantly via hydrolysis whereas its hydroxylation occurs predominantly via the path of direct OH attack. 相似文献
103.
The pinacol reaction of beta-halogenated alpha,beta-unsaturated aldehydes was promoted by titanium tetraiodide to give coupling products in good yields with high dl-selectivity. Subsequent reduction with H(2)/Pd-C gave saturated vic-diols in good yields. Heck coupling reaction enabled the displacement of halogens with vinyl groups without the loss of stereochemical integrities. [reaction: see text] 相似文献
104.
本报道用了2,6-二氯-4-溴偶氮胂作显色剂测定微量铀(Ⅵ)的光度法。在H2SO4介质中,铀(Ⅵ与)2,6-二氯-4-溴偶氮胂形成1:2络合物,其λmax=640nm;表观摩尔吸光系数为1.1×10^5L.mol^-^1.cm^-^1;铀的浓度在0.0-22.0μg/ml内符合比耳定律。方法具有灵敏度高,选择性好,操作方便等特点并已用于废水及矿样中微量铀(Ⅵ)的测定。 相似文献
105.
电吸附技术的应用与研究 总被引:8,自引:0,他引:8
本文综述了活性炭、活性炭纤维、炭气凝胶及活性氧化铝等材料的电吸附/脱附技术的研究进展。主要介绍了其在去除水中无机和有机污染物方面的应用,并对今后的研究方向提出了建议。 相似文献
106.
A catalytic photometric method with a flow-injection system is described for the determination of 9,10-phenanthrenequinone. It is based on the catalytic effect of 9,10-phenanthrenequinone on the redox reaction of 1,2-dinitrobenzene with formaldehyde under alkaline conditions. 9,10-Phenanthrenequinone at the 5.0 x 10(-8)-5.0 x 10(-6)M level can be determined at a rate of 20 samples/hr. The detection limit is 1.0 x 10(-8)M (40 pg in a 10-microl injection). 相似文献
107.
The hydrothermal reaction of YbCl(3) small middle dot6H(2)O with 1,2,4,5-benzenetetracarboxylic dianhydride resulted in [[Yb((b)btec)(1/4)((d)btec)(3/6)(H(2)O)(2)](4).6H(2)O](n)() (1) (H(4)btec = 1,2,4,5-benzenetetracarboxylic acid), and the solvothermal reaction of Er(NO(3))(3) small middle dot6H(2)O or TbCl(3).6H(2)O with 1,2,4,5-benzenetetracarboxylic dianhydride in H(2)O/acetic acid gave rise to [[Er(2)((c)btec)(2/4)((e)btec)(2/4)((f)btec)(2/4)(H(2)O)(4)].4H(2)O](n)() (2) and [[Tb(H(2)btec)(2/4)((f)btec)(3/6)(H(2)O)].2H(2)O](n)() (3), respectively. Complex 1 crystallizes in monoclinic space group C2/m with a = 20.8119(5) A, b = 17.6174(1) A, c = 5.7252(2) A, beta = 92.324(1) degrees, and Z = 1. 1 possesses a three-dimensional framework consisting of eight-coordinate ytterbium centers and two kinds of channels along the c axis. Complex 2 crystallizes in triclinic space group P with a = 9.6739(5) A, b = 11.0039(5) A, c = 11.5523 A, alpha = 104.8330(10) degrees, beta = 91.0000(10) degrees, gamma = 114.2570(10) degrees, and Z = 2. 2 has a three-dimensional framework comprising both eight- and nine-coordinate erbium centers and channels along the a axis. Complex 3 crystallizes in monoclinic space group P2(1)/n with a = 10.7246(12) A, b = 7.1693(9) A, c = 17.158(2) A, beta = 97.109(2) degrees, and Z = 4. 3 shows a three-dimensional framework containing nine-coordinate terbium centers and channels along the b axis. Uncoordinated water molecules occupy the channels in the three complexes. TGA and XRPD were determined for the three complexes, and the results illustrate that the framework of 1 is retained upon removal of uncoordinated and coordinated water molecules. 相似文献
108.
Liposomes prepared from synthetic amphiphiles. I. Their technetium labeling and stability 总被引:1,自引:0,他引:1
In order to apply liposomes prepared from synthetic amphiphiles containing amino acid residues to radiopharmaceuticals, their labeling with 99Tc or 99mTc and stability in saline or in serum were investigated. These liposomes were highly labeled by embedding stearylamine-diethylenetriamine pentaacetic acid as a ligand of technetium. The labeling was more efficient at pH 7.0 than at pH 4.0 or 8.5. Among these technetium-labeled liposomes tested, liposomes containing the alanine residue were stable in saline or in 50% serum at 37 degrees C for at least 24 h, in contrast to liposomes (phosphatidylcholine: cholesterol = 1:1 molar ratio) whose stability had been enhanced by adding cholesterol. 相似文献
109.
S. Tamai J. Kamada T. Ono T. Kuroki K. Goto A. Yamaguchi 《Journal of polymer science. Part A, Polymer chemistry》2002,40(3):423-428
Polyimide containing an indan unit and alkyl moiety with a high molecular weight was prepared from 5,7‐diamino‐1,1,4,6‐tetramethylindan and 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride. This polyimide was amorphous and soluble in common organic solvents, such as tetrahydrofuran, chloroform, and cyclopentanone. Thermogravimetry of the polyimide showed good thermal stability, indicating that a 10% weight loss of the polyimide was observed at 500 °C in nitrogen. The glass‐transition temperature of the polyimide was not observed by DSC measurement between room temperature and 400 °C at a heating rate of 10 °C/min (Apparatus: DSC3100 MAC Science Co., Ltd.). Transparency of the polyimide at 365 nm was 80%. The polyimide acted as a photosensitive resist of negative type by UV radiation. The resist had a sensitivity of 31 mJ/cm2 and a contrast of 2.3 when it was developed with cyclopentanone at room temperature. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 423–428, 2002 相似文献
110.
Ichinose H Michizoe J Maruyama T Kamiya N Goto M 《Langmuir : the ACS journal of surfaces and colloids》2004,20(13):5564-5568
Enzyme-based electron-transfer reactions involved in the cytochrome P450 monooxygenase system were investigated in nanostructural reverse micelles. A bacterial flavoprotein, putidaredoxin reductase (PdR), was activated and shown to be capable of catalyzing the electron transport from NADH to electron-carrier proteins such as cytochrome b5 (tCyt-b5) and putidaredoxin (Pdx) in reverse micelles. Ferric tCyt-b5 in reverse micelles was effectively converted to its ferrous form by the exogenous addition of separately prepared reverse micellar solution harboring PdR and NADH. The fact that direct interactions of macromolecular proteins should be possible in the reverse micellar system encouraged us to functionalize a multicomponent monooxygenase system composed of the bacterial cytochrome P450cam (P450cam), putidaredoxin (Pdx), and PdR in reverse micelles. The successful camphor hydroxylation reaction catalyzed by P450cam was significantly dependent on the coexistence of Pdx, PdR, and NADH but not H2O2, suggesting that the oxygen-transfer reactions proceeded via a "monooxygenation" mechanism. This is the first report of a multicomponent cytochrome P450 system exhibiting enzymatic activity in organic media. 相似文献