摘要:

A complete analysis of the 360 MHz1H NMR spectra of diosmin and hesperidin in DMSO-d6solution has been performed and the corresponding values for chemical shifts and coupling constants given. Two sets of NMR signals have been detected in aged hesperidin samples, and based on NMR parameters and HPLC data, the second set has been assigned to an hesperidin isomer with a change of the natural configuration at the C2 atom.

ISSN:0038-7010    

DOI:10.1080/00387018608069253

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Starting from Perow's statistical model concerning the solvatochromy and solvatofluorochromy of complex organic compounds useful relations have been deduced for studying the phenomena that take place in a diluate ternary solution at the solute-solvent interface taking into account both the solvation and the complexing phenomenon.

ISSN:0038-7010    

DOI:10.1080/00387018608069254

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

NOE phenomenon has been observed and employed to distinguish rapid aromatic hydrogen exchange in primaquine and related analogues. The hydrogens at carbons 5 and 7 in the quinoline nucleus undergo acid-catalyzed H/D exchange with faster exchange at C-5 relative to C-7.

ISSN:0038-7010    

DOI:10.1080/00387018608069255

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The IR and NMR spectra of the tosylate salts of 12 new N-hydroxyguanidine derivatives are compiled. The various IR absorption peaks in KBr pellets and the chemical shifts of the aldehyde moiety of the Schiff bases of N-hydroxy-N'-aminoguanidine and the N-hydroxy-N'-aminoguanidine group of these compounds in dimethyl sulfoxide are reported.

ISSN:0038-7010    

DOI:10.1080/00387018608069256

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Low frequency Raman spectra from 20 to 200 cm−1of δ-valerolactam and ϵ-caprolactam in CCl4solution have been measured at different temperatures (25–80°C). Experimental data were transformed to the R(v) representation and the assignments of some bands are discussed based on measurements of depolarization ratio. The spectral features indicate that C2symmetry dimers are predominant. Previous assignments of some bands are also revised.

ISSN:0038-7010    

DOI:10.1080/00387018608069257

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

17O-NMR spectra, of ortho, meta and para substituted nitrobenzene are reported. The17O nucleus of NO2group in ortho derivatives absorb at lower field that meta and para compounds. Moreover, width line of17O resonance appears to be strongly dependent by substituent position. The17O chemical shifts are correlated with U. V. spectra and X-ray diffraction data.

ISSN:0038-7010    

DOI:10.1080/00387018608069258

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The previously reported1linear correlation between the extinction coefficient of the longest wavelength band and the sum of the Hammett op+ values in arenetricarbonylchromium complexes has been extended to now include fifty-seven compounds. A possible “meta effect” and the solvent sensensitivity of these compounds was also studied.

ISSN:0038-7010    

DOI:10.1080/00387018608069259

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Infrared spectra of the products of one- and two -step reduction of both benzil and benzil-180 have been investigated in dimethylsulfoxide-d6and tetrahydrofurane solutions. Anion-radicals have been obtained by electrochemical reduction of benzil and benzil-180; dinegative ions have been prepared by reduction of the same ketones with potassium mirrorin vacuo. The band assignment has been performed using the group vibrational concept and isotopic shift data. The previous assignment of the C˭O stretching band of benzil anion-radical-has been discussed and corrected. Two bands in the infrared spectra of benzil dianion have been found to be sensitive upon180 isotope labelling. This result certifies the presence of cis-configuration of benzil dianion in the investigated solutions. A decrease of ca. 290 cm-1has been found forvC˭O after the transformation of the neutral benzil into an anion-radical. Conversion of benzil anion-radical into dianion has been accompanied by an additionalvC˭O downward shift of 105 cm−1

ISSN:0038-7010    

DOI:10.1080/00387018608069260

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

During an investigation of the diterpene constituents ofBriareum asbestinumwe isolated the previously reported brianthein-X. Through the use of two-dimensional heteronuclear chemical shift correlation and relayed coherence transfer, four of the previously reported13C-resonance assignments are revised.

ISSN:0038-7010    

DOI:10.1080/00387018608069261

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:0038-7010    

DOI:10.1080/00387018608069262

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor