摘要:

Diastereotopic nuclei are intrinsically nonequivalent both chemically and magnetically.1Magnetic nonequivalence is either isochronous or anisochronous depending upon whether the two nuclei in question are magnetically nonequivalent in the spin-coupling sense (unequally coupled to a third nucleus) or in the chemical-shift sense (different nuclear) shieldings).2While both isochronous and anisochronous magnetic non-equivalence have been thoroughly documented in1H- and19F-nuclear magnetic resonance studies,1, 2reported examples from natural abundance13C-magnetic resonance (cmr) spectra are conspicuously rare.3

ISSN:0038-7010    

DOI:10.1080/00387017508067377

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Experimental potential energy curves for the X1Σ and A1Σ states of BaO have been calculated using the method of Rydberg-Klein-Rees as modified by Kirschner and Watson. The dissociation energy of BaO molecule as estimated using the curve fitting method has been compared with Do(BaO) obtained, using the short-wavelength limit of the chemiluminescence in a controlled reaction of Ba + ×No2vapors. A critical discussion of the various results has also been given with special reference to the complete sub-shell structure of ‘Ba’ atom.

ISSN:0038-7010    

DOI:10.1080/00387017508067378

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Experimental potential energy curves have been constructed for XO+gand AO+ustates of gaseous Te2by partial numerical integration directly. Then the dissociation energies for these states have been estimated by fitting the H‒H function to the experimental potential energy curves.

ISSN:0038-7010    

DOI:10.1080/00387017508067379

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

In the atomic absorption spectrometry with the long absorption tube using a hydrogen-air flame, only the total consumption type of the burners, e.g., Beckman1or ring burners2, have been used for the input of a sample solution to the flame. The use of the indirect input method with nebulization chamber has never been attempted, though, by use of a commercially available apparatus with nebulization chamber, the large increase of the sensitivity has been easily obtained by heating the chamber and nebulizing air3–5.

ISSN:0038-7010    

DOI:10.1080/00387017508067380

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Various mineral acids are compared in measuring metals in plant materials by flame and flameless atomic absorption spectrometry. NBS-SRM 1571, Orchard Leaves, is utilized as the plant material. The combination of H2SO4and HNO3is found to be the most suitable for measuring Fe, Mn, Cu and Zn by flame atomic absorption spectroscopy, while HNO3is found to be the best for measuring Cu, Mn, and Pb by flameless Atomic Absorption spectroscopy.

ISSN:0038-7010    

DOI:10.1080/00387017508067381

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

ISSN:0038-7010    

DOI:10.1080/00387017508067382

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The laser Raman spectra of crystalline [(CH3)4N] HgCl3and [(CH3)4N]2HgCl4have been studied in the 400–20 cm−1region. All expected Raman active modes for the HgCl3−and HgCl4−2ions are observed and assignments of the vibrational frequencies are made in relation to the structure of the anions.

ISSN:0038-7010    

DOI:10.1080/00387017508067383

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

It is well known that the study of the fine structure of the IR bands, together with the polarization of the Davidov splitting components and with the analysis of the changes in selection rules, going from vapor and liquid states to the crystal, permit the determination of the local symmetry, factor group symmetry and number of molecules in the unit cell of a molecular crystal. The activity of each multiplet component and its polarization in the IR spectrum of the crystal is determined in fact by affiliation with one or the other factor group symmetry class, and the corresponding transition moments μx, μyand μz, active in the IR absorption, are directed along the characteristic directions of the unit cell axes, determined by its symmetry.

ISSN:0038-7010    

DOI:10.1080/00387017508067384

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The IR spectra of piperidine dissolved in n-heptane revealed that a self-association equilibrium via weak hydrogen bonds exists in this system. The dimerisation constant was found to be 0.35 1·mol−1at 29°. No higher associates than dimers were found.

ISSN:0038-7010    

DOI:10.1080/00387017508067385

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

ISSN:0038-7010    

DOI:10.1080/00387017508067386

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor