摘要:

Although quite a few papers have been devoted to the13C NMR study of pyrazoles, there is one problem that has not yet been satisfactorily solved, namely the assignment of the2JCH and3JCH coupling constants. In general, the3C chemical shifts and1JCH coupling constants can be easily attributed, but the assigment of the long-range2JCH and3JCH coupling constants is not straight forward. In N- substituted pyrazoles, where annular tautomerism is prevented, each carbon atom can have two long-range coupling constants with the ring protons.

ISSN:0038-7010    

DOI:10.1080/00387018408075703

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The absorption spectra of a series of polysubstituted arenetricarbonylchromium complexes were studied. A linear correlation between the extinction coefficient of the longest wavelength band and the sum of the Hammett σp+ values was obtained.

ISSN:0038-7010    

DOI:10.1080/00387018408075704

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The temperature independent esr spectrum of di-i-Propyl-t-butylmethyl radical, derived from photolysis of oxalate ester, indicates a frozen “cogwhell” conformation for this specie. The neo-pentyl substituted oxalate esters are suggested to qive β-hydrogen abstraction on presence of di-t-butylperoxide on photolysis.

ISSN:0038-7010    

DOI:10.1080/00387018408075705

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The infrared spectra of the complexes formed between 1-methyl, 2-pyrimidone, 3-methyl,4-pyrimidone, amino-2-pyrimidine, 1,3-dimethyl-uracil and HBr, HCl or DCl have been measured between 4000 and 300 cm−1in KBr. Complex formation brings about strong perturbations in the infrared spectra of the base. These vibrational perturbations are discussed in terms of structural data given by x-ray diffraction methods. Some vibrational modes of the bases are more sensitive to the deuteration and this fact is interpreted by different coupling between some planar vibration modes and the νNH+or νND+modes.

ISSN:0038-7010    

DOI:10.1080/00387018408075706

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Spectroscopic studies on the reaction of p-chloranilic acid with antazoline base are reported. These include UV/VIS and IR spectrophotoraetry, electron spin resonance (ESR) and nuclear magnetic resonances (1H-NMR &13C-NMR). The results reveal that the antazoline-p-chloranilic acid product is an ion pair salt rather than a charge-transfer complex.

ISSN:0038-7010    

DOI:10.1080/00387018408075707

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The Hitachi Zeeman atomic absorption spectrometer system is used to evaluate the influence of observation height and C2H2flow rate upon the atomic absorption sensitivity (slope of calibration curve) and upon the atomic absorption signals for 6 elements in an C2H2/Air flame and for 3 elements in an C2H2/N2O flame. Fuel-rich conditions result in greater absorption signals and sensitivities in all cases even though there is a significant temperature drop. Optimal observation heights for each case are evaluated. Greater linearity of analytical calibration curves occurs for fuel-rich conditions under Zeeman background correction than under no background correction. The Zeeman atomic absorptionflamespectrometer should find more use in the future.

ISSN:0038-7010    

DOI:10.1080/00387018408075708

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The powder-infrared spectra of different crystalline compounds containing the tetrahedral Cro3-4, anion have been recorded and analyzed with the aid of the site symmetry rules. In some cases Raman data are also reported. The effect of the different crystalline environments is discussed in detail and comparisons with isostructural phases are also made. A definitive assignment for the internal vibrations of the CrO3-4, ion is proposed and a new set of force constants has been calculated fron a modified valence force field.

ISSN:0038-7010    

DOI:10.1080/00387018408075709

出版商:Taylor & Francis Group    

年代:1984

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:10.1080/00387018408075702

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor