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231.
标题配合物 [Cu(C8H4 F3O2 S) 2 (C12 H8N2 ) ]·C3H6 O属于三斜晶系 ,空间群为P1,并测得如下晶胞参数a =10 .5 77(3) ,b =15 .72 2 (4) ,c =10 .133(2 ) ,α =94 .5 3(2 ) ,β =10 0 .81(2 ) ,γ =96 .18(2 )° ,V =16 37.0 3 3,Z =2 ,Mr =74 4.18,Dx =1.5 1× 10 6 g·m- 3,F(0 0 0 ) =5 2 6 ,μ =8 2 4cm- 1,最终偏差因子为R =0 .0 83,Rw=0 .0 74。Cu(II)与 2个 4 ,4 ,4 三氟 1 (2 噻吩基 )丁二酮 1,3中的四个氧原子和菲咯啉中的两个氮原子 ,组成了一个畸变的八面体构型。 相似文献
232.
233.
A new amide tripodal ligand, 6-[2-(2-diethylamino-2-oxoethoxy)ethyl]-N,N,12-triethyl-11-oxo-3,9-dioxa-6,12-diazatetradecanamide (4) has been designed and synthesized for the recognition of rare earth ions. Three representative complexes of trivalent lighter (La), middle (Gd), and heavier (Er) rare earth ions with 4 were synthesized and characterized by X-ray crystallography. In the complex, the heptadentate forms a cup-like coordination cavity encapsulating the central ion. Different supramolecular complex dimers are constructed by pi-pi interaction and van der Waals forces in accordance with the lanthanide contraction. The differences of the cavity and dimer structures were investigated further by assessing the separation efficiency of in multitrace solvent extraction of rare earth ions from picrate acid solution and the ligand has the best separation factor for 147Pm(III). 相似文献
234.
235.
Aggregation of sodium 1-(n-alkyl)naphthalene-4-sulfonates in aqueous solution: micellization and microenvironment characteristics 总被引:2,自引:0,他引:2
Tan XL Zhang L Zhao S Li W Ye JP Yu JY An JY 《Langmuir : the ACS journal of surfaces and colloids》2004,20(17):7010-7014
In aqueous solution, the micellization and microenvironment characteristics of the micelle assemblies of three anionic surfactants, sodium 1-(n-alkyl)naphthalene-4-sulfonates (SANS), have been investigated by steady-state fluorescence and time-resolved fluorescence decay techniques using pyrene, Ru(bpy)3(2+), and 1,6-diphenyl-1,3,5-hexatriene as fluorescence probes. The critical micelle concentrations (cmc's), effective carbon atom numbers (neff's), hydrophilic-lipophilic balances (HLBs), mean micelle aggregation numbers, micropolarities, and microviscosities of these surfactant micelles have been determined. The logarithmic cmc of the alkylnaphthalene sulfonates decreases linearly with an increase in the neff. The logarithmic aggregation number of the alkylnaphthalene sulfonates increases linearly with an increase in the neff. However, in contrast to the alkylsufonates and the alkylbenzene sulfonates, the aggregation for these alkylnaphthalene sulfonate molecules is less sensitive to the increase in the neff. The micropolarity of these alkylnaphthalene sulfonate micelles is less sensitive to the increase in the alkyl chain length and is lower than that of sodium dodecyl sulfate (SDS). The microviscosity of these alkylnaphthalene sulfonate micelles increases with an increase in the alkyl chain length and is lower than those of nonionic surfactants and zwitterionic surfactants. These results suggest that naphthyl rings have a notable effect on the micellization of SANS. 相似文献
236.
Ai‐Hua Zhao Yan Zhang Zhao‐Hui Xu Jian‐Wen Liu Wei Jia 《Helvetica chimica acta》2004,87(12):3160-3166
Three new enmein‐type ent‐kaurenoids, i.e., the two pairs 1 and 2 of 20‐epimers and the (20R)‐isomer 3 , besides the seven known diterpenoids 4 – 10 , were isolated from the aerial parts of Isodon serra. Their structures were elucidated by spectroscopic techniques and X‐ray diffraction. The immunosuppressive effect for T‐lymphocytes proliferation induced by Con A in BALB/c mouse was evaluated for the isolates 1 – 10 . They all displayed a remarkable inhibitory effect, with multi‐glycosides of Tripterygium wilfordii as positive reference substance (Table 3). 相似文献
237.
The interaction of pinacyanol chloride(PC) with nucleic acids has been investigated by a series of experiments.Extensive hypochromism,appreciable peak shifts,isosbestic points and new peaks of the product of binding to nucleic acids in the spectra were observed.They showed that the interaction between PC and nucleic acids occurred.The results from absorption spectra of DNA,DNA melting,electrophoresis and fluorescence polarization studies have indicated that PC binds to DNA in nonintercalative way.Consistent with the nonintercalation,the studies of fluorescence titration and absorption titration specified that the binding of PC to nucleic acids occurred by an outside stacking binding,in which nucleic acids served for acting templates,The fact that the new absorption peaks of bound PC at ca,485nm are just close to the absorption bands of Haggregate of PC at high concentrations without DNA further supports the outside stacking binding mode,In addition,other evidence indicated that the interaction between PC and nucleic acids is not purely electrostatic. 相似文献
238.
Weiping Wang Bo Liao Tianming Wang Wen Zhu 《International journal of quantum chemistry》2006,106(9):1998-2005
A 3D graphical representation of DNA sequences, which has no circuit or degeneracy, is derived for mathematical denotation of DNA sequence. Based on this graphical representation, we propose a new sequence distance measure. We make use of the corresponding similarity matrix to construct a phylogenic tree by virtue of the fuzzy theory. The examination of phylogenic tree belong to eight species illustrates the utility of our approach. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006 相似文献
239.
Zhang X Lü Z Wen M Liang H Zhang J Liu Z 《The journal of physical chemistry. B》2005,109(3):1101-1107
We report herein the template-directed synthesis, characterization, and electric properties of single-walled carbon nanotube- (SWNT-) based coaxial nanowires, that is, core (SWNT)-shell (conducting polypyrrole and polyaniline) nanowires. The SWNTs were first dispersed in aqueous solutions containing cationic surfactant cetyltrimethylammonium bromide (CTAB) or nonionic surfactant poly(ethylene glycol) mono-p-nonyl phenyl ether (O pi-10). Each individual nanotube (or small bundle) was then encased in its own micellelike envelope with hydrophobic surfactant groups orientated toward the nanotube and hydrophilic groups orientated toward the solution. And thus a hydrophobic region within the micelle/SWNT (called a micelle/SWNT hybrid template) was formed. Insertion and growth of pyrrole or aniline monomers in this hybrid template, upon removal of the surfactant, produce coaxial structures with a SWNT center and conducting polypyrrole or polyaniline coating. Raman and Fourier transform infrared (FTIR) spectroscopy and scanning (SEM) and transmission (TEM) electron microscopy were used to characterize the composition and the structures of these coaxial nanowires. The results revealed that the micellar molecules used could affect the surface morphologies of the resulting coaxial nanowires but not the molecular structures of the corresponding conducting polymers. Electric properties testing indicated that the SWNTs played the key roles in the conducting polymer/SWNT composites during electron transfer in the temperature range 77 K to room temperature. Compared with the SWNT network embedded in the conducting polymers, the composites within which SWNTs were coated perfectly by the identical conducting polymers exhibited higher barrier heights during electron transfer. 相似文献
240.
Khattari Z Ruschel Y Wen HZ Fischer A Fischer TM 《The journal of physical chemistry. B》2005,109(8):3402-3407
The surface shear viscosity of a myelin mimetic Langmuir monolayer is investigated upon adsorption of myelin basic protein (MBP). We measure an increase of the surface shear viscosity at picomolar concentrations of the protein, suggesting that the globular conformation of MBP changes upon adsorption at the monolayer. The conformational change enables hydrodynamic interactions of the proteins, with a typical separation of hundreds of nanometers. This unfolding is essential for the compactification of the myelin sheath, serving an enhanced saltatory signal transduction in vertebrates. The viscometry used extends the sensitivity of standard surface viscometers toward lower viscosities. 相似文献