摘要:

AbstractStudies on ring‐opening polymerization of chloromethyl thiirane with rare earth catalysts and functional resins synthesized therewith were reviewe

ISSN:1001-604X    

DOI:10.1002/cjoc.20020200402

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractThe methods for preparing the H2O2generating air (oxygen) electrode and the composite electrode of photocatalyst‐TiO2/C loading on the surface of the air (oxygen) electrode were introduced. In the case of the composite electrode, the current efficiency of electro‐generated H2O2is higher than 80% (J≤ 15 mA/cm2). The degradation of aniline was used as an example to measure the influence of the composite electrode and compared with the system in which the air (oxygen) electrode and the photocatalyst‐TiO2were separated. The results confirmed that the composite electrode played an active role on accelerating the degradation rate of aniline. According to the measurement of the polarization curves of composite electrode and TiO2photo anode, and of the adsorbing amount of aniline on the surface of the composite electrode, the principle of descending the recombination rate of photo‐generated electron and hole and of enhancing the oxidation rate of organic molecule was described. The mechanism about the degradation of aniline was also

ISSN:1001-604X    

DOI:10.1002/cjoc.20020200403

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractBased on the principle and calibration of vapor pressure osmometer and its application in the thermodynamics of the aqueous solutions, the results on aqueous solutions of monomer glycol, PEG200, PEG400, PEG1500and PEG2000, over the different concentration range at various temperatures were reported. Using a linear least‐square fitting routing, the osmotic coefficients were fitted by a simple polynomial equation. It was found that the relationship between the molar osmotic coefficients (ϕ) and the molar concentration (c) of the solutions are in a quite good agreement with the fitted polynomial equation at various temperatures over the different concentration range. The experimental results also show that over the studied concentration range and at various temperatures, the concentration dependence of the molar osmotic coefficients of the aqueous solution systems with the solutes of PEG200, PEG400, PEG1500and PEG2000are totally presented in a rising trend, and their temperature dependence of the osmotic coefficients of the aqueous solution systems of the molar concentration exhibits their own regularities, respectively. The aqueous glycol solution system exhibits the properties of the dilute soluti

ISSN:1001-604X    

DOI:10.1002/cjoc.20020200404

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractThe aggregation of dansyl chloride (DNS‐Cl) in acetone has been studied in detail by steady‐state fluorescence techniques. It has been demonstrated that DNS‐Cl is stable in acetone during purification and aggregation study processes. The aggregates are not solvolyzed in acetone, and do not take part in any chemical reactions either. It has been found that DNS‐Cl tends to aggregate even when its concentration is much lower than its solubility in acetone. The aggregation is reversible, and both the aggregation and the deaggregation are very slow processes. Introduction of SDS has a positive effect upon the formation and stabilization of the agg

ISSN:1001-604X    

DOI:10.1002/cjoc.20020200405

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractComplexation between Rhodamine B (RB) and sulfonated calix [n] arenes (SCnA) were studied by means of UV‐vis spectroscopy and fluorescence spectroscopy. In the presence of sulfonated calix[n] arenes, the absorption band of Rhodamine B shifts to longer wavelength and its intensity decreases. The formation of a host‐guest type complex also results in the fluorescence quenching of Rhodamine B. The association constants for the RB/SCnA complexes increase in the order of SC4A

ISSN:1001-604X    

DOI:10.1002/cjoc.20020200406

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractTwo triangular molybdenum‐tellurium clusters, Mo3Te7‐[S2CN (CH2CH2OH2]3I (1) and Mo3Te4Y3[S2P(iPrO)2]3I (Y3= 1. 43Te+ 1.57S) (2), were obtained from the reaction of K · HOdtc [HOdtc = S2CN(CH2CH2OH)2] or K·iPr2dtp (iPr2dtp = S2P[OCH(CH3)2]2) with a mixed product of elements Mo, Te(S) and I2at high temperature. The structures of the two compounds were determined by X‐ray crystallography study. Crystal data are, (1): monoclinic, P21/n, a= 1.6256(3),b= 1.3264(2),c= 1.8808(4) nm, β=96.923°,V= 4.025.9 (14) nm3,Dcal= 3.050g·cm‐3,Z= 4, and (2): monoclinic,P21/n, a= 1.4564(2),b =2.3917(4),c= 1.5094(3) nm, β = 114.35(2)°,V= 4.0259(14) nm3,Dcal= 2.449 g·cm−3andZ= 4. Single crystal analyses show that 1 consists of discrete Mo3Te7[S2CN(CH2CH2OH)2]3I connected into three‐dimensional framework via hydrogen bonds, while 2 forms a linear chain via

ISSN:1001-604X    

DOI:10.1002/cjoc.20020200407

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractUltrathin multilayer films of a rare‐earth‐containing polyoxometalate Na9[Eu(W5O18)2] (EW) and poly(allylamine hydrochloride) (PAH) have been prepared by layer‐by‐layer self‐assembly from dilute aqueous solutions. The fabrication process of the EW/PAH multilayer films was followed by UV‐vis spectroscopy and ellipsometry, which show that the deposition process is linear and highly reproducible from layer to layer. An average EW/PAH bilayer thickness ofca. 2.1 nm was determined by ellipsometry. In addition, the scanning electron microscopy (SEM) image of the EW/PAH film indicates that the film surface is relatively uniform and smooth. The photoluminescent properties of these films were also investigated by fluorescence s

ISSN:1001-604X    

DOI:10.1002/cjoc.20020200408

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractA new cadmium (II) coordination polymer, [Cd(TTTMB)2]‐(SO4) · 21H2O, where TTTMB =1,3, 5‐tris (imidazol‐1‐yl‐methyl)‐2,4,6‐trimethylbenzene, was obtained by self‐assembly of tripodal ligand TTTMB with CdSO4·2.7H2O in acetonitrile, and characterized by X‐ray crystallography. The crystal data belongs to monoclinic space groupCcwith cell parametersa= 1.16891(4) nm,b=2.06671(6) nm,c= 2.48185(7) nm, β = 97.8560(10)°,R= 0.0487,wR= 0.1211. The results of structure analysis indicate that each TTTMB ligand coordinates three metal atoms and in turn each Cd(II) atom with octahedral coordination geometry connects six nitrogen atoms of imidazole group from six different TTTMB ligands to produce a 2D honeycomb network structure. There are a lot of water molecules linked by hydrogen bonds and occupied the channels formed in

ISSN:1001-604X    

DOI:10.1002/cjoc.20020200409

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractK2NiF4type compounds Sm2‐xSrxCuO4(0 ≤x≤ 1.2) were prepared. Rietveld refinement of powder diffraction data snows that the crystal system of these compounds belongs to T type tetragonal structure of space groupI4/mmm, and the addition of Sr causes a dramatic shift of the O(I) ions along thecaxis from Sm (Sr) toward Cu while scarcely affecting the Cu—O (II) bond in basal CuO4plane. From XRD data, it can be seen that when 0.0 ≤x≤ 0.6, Sm2‐xSrxCuO4belongs to a single‐phase K2NiF4type structure, while atx⩾ 0.7, both the free SrO phase and the CuO phase exist in these compounds. From the results of XPS and Rietveld refinement, it can be seen that after replacing Sm3+with Sr2+of lower valence, the valence of Cu and Sm does not change apparently, and thus some defect must be formed at the oxygen ion positions and/or position A on A2BO4to keep charge balance and to stabil

ISSN:1001-604X    

DOI:10.1002/cjoc.20020200410

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractThe structure of the complex { [Eu (p‐MOBA)3· 2H2O] · 0.5H2O·0.5(4,4′‐bipy)}∞(p‐MOBA:p‐methoxybenzoate, 4,4′‐bipy: 4,4′‐bipyridine) was determined by single crystal X‐ray diffraction study. Each europium atom is coordinated with two oxygen atoms of the chelated carboxyl group, four oxygen atoms of the four bidentate bridging carboxylate groups and two oxygen atoms of two water molecules, forming an infinite polymeric chain structure. Excitation and luminescence spectra were observed at 77 K. The high resolution spectrum of the complex shows that the europium ion site in the crystal has low symmetry. The complex displays intense luminescence which may be related to thep‐MOBA ligand and

ISSN:1001-604X    

DOI:10.1002/cjoc.20020200411

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY