摘要:

AbstractThis paper has improved Hickman's nonadiabatic collision model by substituting Hickman's constant velocity classical straight line trajectory approximation with the solution of motion equationmR=−dV(R)/dR, and has calculated the cross sections of ion‐pair formation Cs+O2→Cs++O−2with the improved nonadiabatic collision model (INCM). A comparison of our results with other theoretical and experimental results has be

ISSN:1001-604X    

DOI:10.1002/cjoc.19950130302

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

年代:1995

数据来源: WILEY

摘要:

AbstractMonodispersed particles of doped yttrium basic carbonates were prepared at aging at elevated temperature corresponding salts solutions in the presence of urea. Coprecipitation in mixed solutions of yttrium, lanthanum and neodymium salts under similar experimental conditions yielded composite particles of basic carbonates. The content of the three metals in the solids followed closely the initial composition of the reacting solutions. On calcination all prepared solids converted to their corresponding oxides while retaining their particle morphology. The so‐prepared powders were characterized by various technique

ISSN:1001-604X    

DOI:10.1002/cjoc.19950130303

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe complexes [Pd(phen)(aa)]Cl·3H2O, where phen is 1,10‐phenanthroline and as is the anion of glycine (gly),DL‐alanine (ala),DL‐serine (ser) orDL‐asparagine (asn), were synthesized and characterized by spectroscopies. The NMR signals were assigned completely on the basis of the double irradiation,1H‐1H COSY and1H‐13C COSY techniques. In the1H NMR spectra of phen in the complexes, the signals of 2‐H and 9‐H show upfield shifts 0.8–1 ppm, while the signals of 4‐H and 3‐H show downfield shifts or almost no shift, as compared to the free phen ligand, and the signal of 4‐H appears in the lowest field. The signals of ring B which istransto the carboxyl group show significant upfield shirts as compared to those of ring A. The probable structures were described on the basis of a metal‐non‐bonded hydrogen interaction,transeffect and ligand‐ligand interaction. There may exist three conformation isomers in the [Pd(phen)(asn)]Cl·3H2O complex at room temperature. The preferred conformation isomer is about 75% in terms of the relative peak areas

ISSN:1001-604X    

DOI:10.1002/cjoc.19950130304

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

年代:1995

数据来源: WILEY

摘要:

AbstractSix novel μ‐oxamido heterobinuclear complexes, namely Cu(oxae)Ln(Me2bpy)2‐(ClO4)3(LnLa, Nd, Gd, Tb, Ho, Er), where oxae denotesN, N'‐bis(2‐aminoethyl)oxamido dianion, Me2bpy is 4,4'‐dimethyl‐2,2'‐bipyridyl, have been synthesized and characterised by elemental analyses, IR, conductivity measurements and electronic spectra. The temperature dependence of the magnetic susceptibility of Cu(oxae)Gd(Me2bpy)2(ClO4)3has been measured over the range 4–300 K. The least‐squares fit of the experimental susceptibilities yieldedJ= 1.87 cm−1. The observed Gd(III)‐Cu(II) coupling is ferromagnetic. One plausible mechanism that can cause a ferromagnetic coupling between Gd(III) and Cu(II) is discussed in te

ISSN:1001-604X    

DOI:10.1002/cjoc.19950130305

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

年代:1995

数据来源: WILEY

摘要:

AbstractHeteroaggregates composed of cationic porphyrin,meso‐tetra(p‐trimethylamino)porphyrin iodide, its zinc complex and anionic phthalocyanine sodium hydxoxygallium 4,4′,4″,4″′‐tetrasulfonated phthalocyanine have been investigated by absorption and fluorescence spectroscopy. It has been found that both free base cationic porphyrin and its zinc complex can form very stable heterodimers with anionic phthalocyanine in water, methanol and dimethylformamide. The stability of the aggregate depends on the polarity as well as the ligation ability of the solvent. No evidence of higher aggregates was detected. Besides axial coordination, steric hindrance which influences the relative orientation of the macrocycles a

ISSN:1001-604X    

DOI:10.1002/cjoc.19950130306

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

年代:1995

数据来源: WILEY

摘要:

AbstractA new type of the surface acoustic wave (SAW) sensor system was delivered. Urease from several kinds of plant seeds was extracted with different extracting solvents. The urease activity, Michaelis constant and other kinetic parameters were estimated for the first time by means of the new device–‐SAW sensor system. Some factors such as pH, temperature, activators and inhibitors are also discussed. The method can be applied to the determination of urea content in human urine and the experimental results consist with those repor

ISSN:1001-604X    

DOI:10.1002/cjoc.19950130307

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

年代:1995

数据来源: WILEY

摘要:

AbstractBy using red yeast (Rhodotorula rubraAS 2.166) resting cells which possess the phenylalanine ammonia‐lyase (PAL, EC 4.3.1.5) activity as biocatalyst, enantiomerically pureS‐3‐(2‐chloro‐phenyl) alanine (2a) andS‐3‐(3‐hydroxyphenyl) alanine (2d) have been synthesized from the corresponding 3‐aryl substituted acrylic acid (1a an

ISSN:1001-604X    

DOI:10.1002/cjoc.19950130308

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

年代:1995

数据来源: WILEY

摘要:

AbstractLarge scale synthesis of oligoribonucleotides has been successfully performed on PEG support by the phosphoramidite approach usingt‐butyldimethylsilyl to protect the 2'‐hydroxyl group of ribonucleoside. By means of this procedure, the dodecamer r(AGUGGUCUUUGU) was synthesized in 98.1% average coupling yield, and 55 mg pure product was obtained from one gram of functionalized

ISSN:1001-604X    

DOI:10.1002/cjoc.19950130309

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

年代:1995

数据来源: WILEY

摘要:

AbstractPerfluoroalkylated glycerol (5, 9) and crown ethers (22, 23, 24) were synthesized starting from glycerol.5was synthesized by allylation of glycerol 1,2‐acetonide followed by perfluoroalkylation initiated with sodium dithionite, reduction of iodide and hydrolysis in good overall yield and was shown to possess good surface activities. Glycerol bis‐ether (9) was synthesized in a similar way. Allyloxymethyl crown ethers (15, 16, 18) were prepared as key intermediates through multi‐step reactions, which were then perfluoroalkylated to give the title crown ethers33, 3

ISSN:1001-604X    

DOI:10.1002/cjoc.19950130310

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

年代:1995

数据来源: WILEY

摘要:

AbstractAtemoyacin A, a new annonaceous acetogenin was isolated from the alcoholic extract of the seeds ofAnnona atemoyaHort (Annonaceae). Its structure and relative configuration were elucidated on the basis of the spectral analysis.

ISSN:1001-604X    

DOI:10.1002/cjoc.19950130311

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

年代:1995

数据来源: WILEY