摘要:

AbstractThe concerted reaction mechanism of the ketene‐methylenimine cycloaddition reaction was reconfirmed by IRC calculation at HF/6–31G* level. Other possible reaction schemes were also studied. Thecisandgauchintermediate cannot be found on the potential energy surface, and thetransintermediate can only lead to a 6‐membered ring product. Therefore, a two step mechanism to form β‐lactam is excluded for the title

ISSN:1001-604X    

DOI:10.1002/cjoc.19960140202

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

年代:1996

数据来源: WILEY

摘要:

AbstractMINDO/3 molecular orbital theory has been used to study the thermal rearrangements of HNCRCR'CO. The results obtained show that the activation energy of this rearrangement depends on the migrating group R and the group R'.

ISSN:1001-604X    

DOI:10.1002/cjoc.19960140203

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

年代:1996

数据来源: WILEY

摘要:

AbstractA new theoretical equation for fluorescence enhancement effect between donor and acceptor has been introduced. By using it we determined the binding constants and numbers of binding sites of five medicines, including chlorogenic acid, forsythiaside norfloxacin, Ciprofloxacin and fluorenone, to γ‐globul

ISSN:1001-604X    

DOI:10.1002/cjoc.19960140204

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

年代:1996

数据来源: WILEY

摘要:

Abstract24‐Membered macrocyclic bicopper(II) complexes wth bridging ligand imidzaolate, SCN−, N3−and H2O respectively were synthesized by condensation of diacetylpyridine with 3‐oxapentane‐1,5‐diamine. As the model compounds of superoxide dismutase (SOD), the relationship between their SOD activities and properties of bridging ligands and redox potentials of copper(II) w

ISSN:1001-604X    

DOI:10.1002/cjoc.19960140205

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

年代:1996

数据来源: WILEY

摘要:

AbstractThe reaction of [NH4]2[MO2S2], AgI and (n‐Bu)4NBr in solid state produced the polyoxometalates [(n‐Bu)4N]4[M6O19][Ag2I4] (1, MMo; 2, MW) which were structurally determined. The crystals of 1 and 2 are isomorphous, monoclinic, space groupP21/c.1,a= l.6624(2),b=1.6699(3),c=l.7217(2) nm, β=98.29(1)°,V=4.729(1) nm3,Z=2,R=0.040,Rw“0.037; 2,a= 1.6636(3),b= 1.6733(3),c= 1.7190(3) nm, β=98.25(1)°,V=4.736(l) nm3,Z= 2,R= 0.038,Rw= 0.047. The results of the structure determination showed that the two compounds had the same structures whose skeletons are composed of [Ag2I4]2. and [M6O19]2‐. The difference of them and heteropolymetalate compounds synthesized in solution is that the title compounds contain cluster. ion, heteropolymetalate and organic cations, while the latter is only composed of heteropolymetalate and

ISSN:1001-604X    

DOI:10.1002/cjoc.19960140206

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

年代:1996

数据来源: WILEY

摘要:

AbstractCapillary electrophoresis (CE)/electrochemical detection (EC) for the simultaneous determination of hydrazine and isoniazid has been developed. The electrochemical method uses a novel modified electrode dispersed with ultrafine platinum particles on the surface of a 30 μm carbon fiber microelectrode. The unique characteristic of the Pt‐particles modified carbon fiber microelectrode is its excellent stability. The current measurement for hydrazine is more sensitive than that of isoniazid. Selective determination of trace amount of free hydrazine in isoniazid and its formulation can be achieved at applied potential of 0.5

ISSN:1001-604X    

DOI:10.1002/cjoc.19960140207

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

年代:1996

数据来源: WILEY

摘要:

AbstractThe reduction processes of anodic PbO2films formed on Pb‐Sb alloys in 4.5 mol.dm−3H2SO4solution at 1.4 V(vs.Hg/Hg2SO4) for 1 h have been investigated by photocurrent method, chronoamperometry, linear sweep voltammetry as well as X‐ray diffractometry. It was found that the reduction of most of the β‐PbO2and part of the α‐PbO2to PbSO4can be completed within 1 s between 0.9 V and 1.0 V(vs.Hg/Hg2SO4) and proceeds much faster than that of the remaining α‐PbO2into photoactive α‐PbOx(1

ISSN:1001-604X    

DOI:10.1002/cjoc.19960140208

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

年代:1996

数据来源: WILEY

摘要:

AbstractA photosensitive electrode was prepared by electrodepositing a membrane of chlorophyll a (Chla) on a SnO2optical transparent electrode, with which and a metal counter electrode a Chla photoelectrochemical cell was formed. Photoinduced current (Ii;) and photoinduced voltage (Vi) of the cell were measured. The dependence ofIi on the properties of metal electrodes was obvious, which was illustrated with mechanism of Chla photoelectrical effects.Ii in this work was as high as 2×0–5A.cm

ISSN:1001-604X    

DOI:10.1002/cjoc.19960140209

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

年代:1996

数据来源: WILEY

摘要:

AbstractAsymmetric total syntheses of (+)‐goniopypyrone (1) and (+)‐deoxygoniopypyrone (2) from methyl cinnamate (7) via (DHQ)2‐PHAL‐OsO4catalyzed asymmetric dihydroxylation and highly stereoselective 2‐furylcopper addition in eight steps and eleven steps with overall yield of 20% and 13%, respectively, are

ISSN:1001-604X    

DOI:10.1002/cjoc.19960140210

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

年代:1996

数据来源: WILEY

摘要:

AbstractThe compound trifluoroiodomethane can be activated to react with the electron donor, 1,4‐dilithiotetraphenyl butadiene, by means of electron transfer catalysis (ETC). The structure of the product, 1,3‐difluorotetraphenyl,benzene (1), was determined by MS, NMR, and X‐ray single crystal diffraction. The conformations of compound 1 and its derivatives were analyized by molecular mech

ISSN:1001-604X    

DOI:10.1002/cjoc.19960140211

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

年代:1996

数据来源: WILEY