NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY. ABNORMAL SPLITTING OF ETHYL GROUPS DUE TO MOLECULAR ASYMMETRY. II
Abstract
Studies of the nuclear magnetic resonance of ethyl groups are being conducted. The spectra of acetaldehyde diethyl acetal (I) and diethyl sulfite (II) are discussed as examples of magnetic nonequivalence of the methylene hydrogens in R-CH2-O-XR1R2R3, where R is equal to CH3 and X is equal to S, C, P, etc. Complete agreement between the computed 40 mc and observed 40 mc spectra of II in benzene was achieved only with the coupling of constants of opposite signs. This dif erence in sign between the geminal and vicinal H-H couplings runs directly counter to the theoretical predictions of Karplus and Gutowsky (J. Chem. Phys. 31:1278, 1959) and Karplus (J. Chem. Phys., 30:11, 1959). Different sets of spin-coupling and chemical-shift parameters were found to give nearly identical theoretical spectra for II in benzene and each of these corresponds well to the experimental spectrum at 60 mc.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1961
- Accession Number
- AD0263333
Entities
People
- Fred Kaplan
- John D. Roberts
Organizations
- California Institute of Technology