摘要:

In recent years lanthanide shift reagents have become increasingly valuable as aids in the analysis of organic structures by nmr spectroscopy.2. They can be used qualitatively in order to simplify nmr spectra, and the lanthanide induced shifts can also be used quantitatively for the mathamatical analysis of a proposed structure.3–6Whatever the particular case may demand, these reagents can be utilized most effectively when the equilibria between shift reagent and substrate are well understood. We have previously reported7the binding abilities of a variety of functional groups with Eu(fod)3, and we have also discussed8the effects of structural variation on the corresponding equilibria of ketones. We now consider structural effects on the association equilibria for a variety of nitriles with Eu(fod)3in CCl4.

ISSN:0038-7010    

DOI:10.1080/00387018208067997

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

In 1977 we undertook investigations1of the Raman spectra of RbHSeO4and NH4HSeO4, prior to the discovery of their ferroelectric nature by a group of workers in Poland.2,3Our studies did not reveal some of the behavior reported by this group, and other studies4,5have indicated phase transitions not observed by us or the Polish group.6–9Consequently we have withheld publishing the results of our earlier studies pending the completion of investigations designed to verify our initial findings and to determine the relationships between our Raman spectra and the reported behavior of these compounds. This paper represents the first in a planned series of communications relating our experiences with these biselenates and our interpretations of those points of disparity between the various studies that have been reported.

ISSN:0038-7010    

DOI:10.1080/00387018208067998

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A method for determination of molecular quantum yields of fluorescent compounds in solution by internal calibration with the signal of spontaneous Raman scattering of the solvent is proposed. An experimental verification of the method is carried out for substances with known quantum yields and satisfactory agreement between experimental results and literature values is obtained.

ISSN:0038-7010    

DOI:10.1080/00387018208067999

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A first order centrifugal distortion analysis has been carried out on the equatorial form of normal thiomorpholine (CH2-CH2-S-CH2-CH2-NH). Twenty eight new Q-branch rotational transitions with J up to 41 were assigned and measured, and the obtained frequencies combined with the low J transitions previously published to determine the Watson's centrifugal distortion constants.

ISSN:0038-7010    

DOI:10.1080/00387018208068000

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A PMR method for quantitative determination of cephalosporins namely cephalotin, cephaloridine, cephradine, cefoxitin and cefotaxime in bulk drugs and pharmaceutical formulation are presented. The determination is based on the integration of the 6-H and/or 7-H of the β-lactam ring system relative to that of the nine protons of t-butanol. The method is rapid, accurate and precise, with an average standard deviations of ± 1.51 in standard mixtures and ± 1.15 in pharmaceutical formulation. The procedure furnishes a specific means of identification of each individual cephalosporin as well as detection of the commonly encountered impurites.

ISSN:0038-7010    

DOI:10.1080/00387018208068001

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

In spite of difficulties in attaining high resolution, the determination of UV-VIS-NIR spectra via diffuse reflectance spectro-scopic measurements on solid powders; provides several advantages. Compounds which are difficult to obtain as suitable single crystals, or are found to be unstable or insoluble in liquid solution, can only be studied by diffuse reflectance spectroscopy. Also, since no solvents are required, any effects due to solvation are eliminated. However, it is not possible to resolve the observed spectrum into its anisotropic components, as in the case of single crystal spectra.

ISSN:0038-7010    

DOI:10.1080/00387018208068002

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Infrared absorption spectra of cyclopentanol-OH and -OD have been measured in the 16 - 3700 cm−1frequency range for crystal IV, III, II, I and liquid phases. The role of both the hydrogen bond and the conformation of a molecule in polymorphism is discussed.

ISSN:0038-7010    

DOI:10.1080/00387018208068003

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The infrared (IR) study of surface species and reactions occurring on solids has contributed markedly to our understanding of surface chemistry and heterogeneous catalysis, and a wide variety of solids has been examined. However, an entire class of catalysts consisting of metal dispersed on carbon has never been studied because the carbon catalyst support absorbs IR radiation so strongly in even the thinnest practical layers that conventional IR techniques fail. As IR data would be helpful in understanding how such catalysts function, we have explored the feasibility of examining carbon-supported catalysts with photothermal beam deflection spectroscopy (PDS) and describe the first IR spectra ot surface species on a Ni-on-carbon catalyst.

ISSN:0038-7010    

DOI:10.1080/00387018208068004

出版商:Taylor & Francis Group    

年代:1982

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:10.1080/00387018208067996

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor