Nuclear Magnetic Resonance Spectroscopy. Spin-Lattice Relaxation of the Acetic Acid Carboxyl Carbon
Abstract
The carbon-13 spin-lattice relaxation times of the carboxyl carbons of acetic acid and its deuterated analogues (CH_3COOD, CD_3COOH, CD_3COOD) have been measured by nuclear magnetic resonance spectroscopy. These measurements reveal that the methyl protons and the hydroxyl proton contribute roughly equally to the total dipolar relaxation of neat acetic acid. Spin-rotation relaxation is also observed in these molecules. The T_1 and NOE values for the carboxyl carbon of acetic acid in aqueous solution each demonstrate a small concentration dependence in the region of high acid concentration. Although samples of 1 M acetic acid contaminated with paramagnetic metal ions show a marked pH dependence of T_1 and NOE, the T_1and NOE values for purified samples are invariant with respect to pH. Some chemical implications of the above behavior are discussed.
Additional Information
© 1976 American Chemical Society. Received June 11, 1975. Supported by the National Science Foundation, and by the Public Health Service, Research Grant No. GM-11072, from the Division of General Medical Sciences.Additional details
- Eprint ID
- 60916
- Resolver ID
- CaltechAUTHORS:20151008-115812951
- NSF
- GM-11072
- U.S. Public Health Service (USPHS)
- Created
-
2015-10-11Created 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
- 5124