摘要:

Complexes of N‐Heterobases and Carbonic Acids in Non‐Aqueous Media. Structural Investigations by FTIR Spectroscopy and Factor AnalysisA series of FTIR spectra of different concentration ratios of dichloroacetic acid and i‐chinoline was investigated by factor analysis. The best results were obtained for difference spectra, in which the dominating bands of the main constituents have been eliminated prior to factor analysis.The component spectra, computed by factor analysis, showed a band of a strong OH…︁N complex. No evidence was found for O…︁HN species, i.e., proton transfer does not occur in the investigated system. The formation of complexes of higher order or of dichloroacetic acid dimers has not

ISSN:0941-1216    

DOI:10.1002/prac.19923340112

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

Crystal and Molecular Structure of 4,5‐Dibenzoylseleno‐1,3‐diselenole‐2‐seloneThe crystal and molecular structure of 4,5‐dibenzoylseleno‐1,3‐diselenole‐2‐selone is described. The compound crystallizes in the monoclinic space group P21/c with a = 9.704, b = 10.839, c = 17.726 [Å], β = 93.43° and Z = 4. The structure is compared with that of the analogous „all‐sulfur”︁ compound. The crystal packing of the heterocycle studied shows surprisingly short intermolecular distances betw

ISSN:0941-1216    

DOI:10.1002/prac.19923340113

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

Synthesis of Substituted 2‐Aminoquinoline‐1‐oxides by Reductive Cyclization of Substituted 3‐(2‐Nitrophenyl)acrylonitrilesAn approach to the class of 2‐aminoquinoline‐1‐oxides is given based on reductive cyclization of appropriate substituted 3‐(2‐nitrophenyl)acrylonitriles. Thus, 2‐nitrobenzylidene compounds1 a – dhave been reductively cyclized by H2/PtO2or H2/Pd‐C under normal conditions to form N‐oxides2 a – d.1H‐NMR data show that1 dhas to be regarded as ethyl(Z)‐2‐cyano‐3‐hydroxy‐3(2‐nitrophenyl)acrylate.The analogous (2‐nitrobenzoyl)acetonitrile3, however, did not cyclize under the same conditions, but yielded anthraniloylacetonitrile4. The results are discussed in comparison with the reaction behaviour of structural related nitronitriles under comparable conditions. A short survey of reactions leading to heterocyclic N‐oxides by re

ISSN:0941-1216    

DOI:10.1002/prac.19923340114

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

Proton Exchange in the NH3· HCl Gas Phase ComplexThe cyclic proton exchange in NH3· HCl is studied by quantum chemicalab initiocalculations in order to characterize the chemical flexibility of the NH3· HCl gas phase system, and to present a model for studying electrophilic substitution reactions. In contrast to the hydrogen bonded molecular complex, the cyclic structureII(C2v) is found to be highly ionic.It represents the transition structure of the proton exchange within the isolated complex. The potential barrier (ΔEpot= EII– EI) of the reaction can only sufficiently be described when including correlation energy. TheC3vcageIIIis also ionic and similar in energy in comparison with the transition struct

ISSN:0941-1216    

DOI:10.1002/prac.19923340115

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

ISSN:0941-1216    

DOI:10.1002/prac.19923340116

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

ISSN:0941-1216    

DOI:10.1002/prac.19923340117

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

ISSN:0941-1216    

DOI:10.1002/prac.19923340118

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

ISSN:0941-1216    

DOI:10.1002/prac.19923340119

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

ISSN:0941-1216    

DOI:10.1002/prac.19923340120

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

ISSN:0941-1216    

DOI:10.1002/prac.19923340122

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY