Nuclear magnetic resonance spectroscopy. Ring-current effects upon carbon-13 chemical shifts
- Creators
- Levin, Ronald H.
- Roberts, John D.
Abstract
Ring currents have played a crucial role in modern chemistry, but they have been analyzed and discussed almost entirely in terms of their effect upon proton nmr chemical shifts. The application of carbon magnetic resonance spectroscopy to this area has received relatively little attention. In fact, only a few alternate and nonalternate aromatic hydrocarbons have been studied in an attempt to elucidate the effect of ring currents on the shifts of carbon nuclei. Unfortunately, the previous conclusions regarding ring-current effects on ^(13)C shifts are not always unambiguous. For example, the observed cmr-shift data for biphenylene might be interpreted in terms of electronegativity and strain superimposed on a diamagnetic ring current, rather than by invoking a paramagnetic ring-current effect, interpretation of the cmr data from biphenylene, pyrene and the majority of other compounds studied suffer somewhat from the lack of suitable model compounds, which are needed to derive "normal" chemical shifts.
Additional Information
© 1973 Pergamon Press. Received in USA 24 October 1972; received in UK for publication 8 December 1972. Supported by the Public Health Service, Research Grant No. GM-l1072 from the Division of General Medical Sciences, and by the National Science Foundation. National Institutes of Health Postdoctoral Fellow, 1971-1972. Contribution No. 4504.Additional details
- Eprint ID
- 61500
- DOI
- 10.1016/S0040-4039(01)95597-2
- Resolver ID
- CaltechAUTHORS:20151023-133452062
- GM-11072
- U.S. Public Health Service (USPHS)
- NSF
- NIH Postdoctoral Fellowship
- Created
-
2015-10-26Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field
- Other Numbering System Name
- Caltech Gates and Crellin Laboratories of Chemistry
- Other Numbering System Identifier
- 4504