Published November 1, 1968
| public
Journal Article
Nuclear Magnetic Resonance Spectroscopy. Conformational Equilibria and Equilibration of 4,4-Difluoropiperidine. Measurement of the N-H Inversion Rate in a Six-Membered Ring
- Creators
- Yousif, Garib A.
- Roberts, John D.
Abstract
Fluorine magnetic resonance spectroscopy has been used to measure the rates of inversion of 4,4-difluoropiperidine. The activation energy (E_s) was found to be 13.9 and 13.5 kcal/mol in methanol and chloroform, respectively. In acetone, N-H nitrogen inversion was found to be slow on the nmr time scale with an E_s of about 10 kcal/mol. The free-energy difference between the forms with the N-H hydrogen axial and equatorial appears to be 0.42 kcal/mol with uncertain sign.
Additional Information
© 1968 American Chemical Society. Received March 9, 1968. Supported by the National Science Foundation. We are deeply indebted to Dr. J. Edgar Anderson and Mr. Frank J. Weigert for many valuable suggestions and help with both the taking of the spectra and the computations of the rates.Additional details
- Eprint ID
- 61084
- DOI
- 10.1021/ja01025a033
- Resolver ID
- CaltechAUTHORS:20151013-145415753
- NSF
- Created
-
2015-10-14Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field
- Other Numbering System Name
- Caltech Gates and CreIIin Laboratories of Chemistry
- Other Numbering System Identifier
- 3627