摘要:

The infrared and Raman spectra of 2-acetylpyrrole dissolved in various solvents, are reported in addition to the Raman spectra of the solid state at pressures up to 30 kbar. The high-pressure behaviour of the Raman-active N-H bands shows beyond any doubt that hydrogen bonded species exist in solid 2-acetylpyrrole, but these results could not distinguish between intra- or intermolecular bonds. Evidence of hydrogen bonded species was also found in solutions of 2-acetylpyrrole in addition to vibrations which point to the existence of ‘free’ oranti-bonded molecules. The hydrogen bonded species existing in solutions and in the solid state appear to be identical.

ISSN:0038-7010    

DOI:10.1080/00387018708081585

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Natural abundance15N-NMR spectra were obtained from quinidine, quinine and epiquinidine. Correlation of the15N chemical shifts with X-ray studies and minimal energy conformer calculations, reported previously, enabled definite conclusions about the solution conformations of these alkaloids. Also the protonation of quinidine in CDCl3was studied. It was determined that the first protonation occurs on the quinuclidine nitrogen and not on the quinoline nitrogen as was reported by Yanuka et al.1

ISSN:0038-7010    

DOI:10.1080/00387018708081586

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Variousa prioritheoretical models have been utilized to predict the temperature dependence of reorientational correlation times of the C-H and C-Cl vectors in liquid CH2Cl2.

ISSN:0038-7010    

DOI:10.1080/00387018708081587

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Spectra excited in hollow cathode discharges operating at high frequency (27.2 MHz) and direct currents have been compared. The cathodes made of copper, brass and steel and argon as a carrier gas were used. Line intensity ratios (Ihf/Idc) for species excited at different pressures have been investigated and discussed.

ISSN:0038-7010    

DOI:10.1080/00387018708081588

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The 60 MHZ1H NMR spectra of racemic commercial fenimide, 4-ethyl-3-methyl-3-phenyl-2,5-pyrrolidine-dioner1, have been studied in CDCl3solution at 28° with the achiral shift reagent, tris(6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionato) europium-(III)2, and the chiral reagent, trist3-(heptafluoro-propylhydroxymethy1ene)-d-camphoratol europium(III)3.Use of2substantially increased the chemical shift differences between resonances of corresponding nuclei in thealphaandbetadiastereomers, simplifying mixture analyses. Use of the chiral3produced enantiomeric shift differences, ΔΔΔ for several signals of1.In particular, with a 0.309 molal solution of1and a3:1, molar ratio near 0.4, four distinct singlets can be seen for the quaternary methyl signal. Direct simultaneous analysis for all four stereoisomers (two pairs of enantiomers) should be feasible.

ISSN:0038-7010    

DOI:10.1080/00387018708081589

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

5-hydroxymethylfurfural reacts with barbituric acid and forms a product with maximum absorbance at 395nm. Via UV-VIS and IR-spectra it becomes evident that in acidic conditions this compound has a conjugated system of bonds with a chynoide-like chromophore. In alkali conditions this chromophore breaks out and the solution is colorless. In this paper is reported a mechanism which is an attempt to explain the stages of this reaction.

ISSN:0038-7010    

DOI:10.1080/00387018708081590

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

N-oxidation of Z-N-Benzylidene arylamine and their ortho-hydroxybenzylidene analogue resulted in unexpected upfield shift of the H-α and C-α chemical shifts. The predominant resonance forms of the nitrones ere discussed. The N-oxidation effects on the13C chemical shift depend upon nitrogen as well as the attached carbon hybridization.

ISSN:0038-7010    

DOI:10.1080/00387018708081591

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The homo and hetero correlated 2D experiments on the title product have led to the unambiguous assignment of proton and carbon NMR spectra.

ISSN:0038-7010    

DOI:10.1080/00387018708081592

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0038-7010    

DOI:10.1080/00387018708081584

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor