17O NMR spectroscopy: torsion angle relationships in aryl carboxylic esters, acids, and amides
Creators
- 1. Georgia State Univ., Atlanta
Description
17O NMR spectroscopic data (natural abundance in acetonitrile at 750C) were obtained for the following series of electronically similar, sterically hindered compounds: aromatic methyl esters, aromatic carboxylic acids, and aromatic amides. Torsional angles were calculated by the molecular mechanics (MM2) method. Linear regression analysis of the estimated torsion angles and the 17O chemical shift data for each series yielded the following results (series, slope δ/degree, correlation coefficient): esters (C=O), 0.70, 0.997; esters (-0-), 0.43, 0.992; acids (-CO2H), 0.56, 0.994; amides (C=O), 0.84, 0.942; N,N-dimethylamides (C=O), 0.6, 0.991. The results are discussed in terms of minimization of repulsive van der Waals interactions by rotation of the functional group out of the plane of the aromatic ring
Additional details
Publishing Information
- Journal Title
- J. Am. Chem. Soc.
- Journal Volume
- 109
- Journal Issue
- 4
- Series
- J. Am. Chem. Soc.
- Journal Page Range
- 1059-1062
- ISSN
- 0002-7863
- CODEN
- JACSA
INIS
- Country of Publication
- United States
- Country of Input or Organization
- United States
- INIS RN
- 18054986
- Subject category
- S37: INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY;
- Resource subtype / Literary indicator
- Numerical Data
- Descriptors DEI
- AMIDES; AROMATICS; CARBOXYLIC ACID ESTERS; CARBOXYLIC ACIDS; CHEMICAL SHIFT; EXPERIMENTAL DATA; MEDIUM TEMPERATURE; MOLECULAR STRUCTURE; NMR SPECTRA; NUCLEAR MAGNETIC RESONANCE; OXYGEN 17; STEREOCHEMISTRY; VIBRATIONAL STATES
- Descriptors DEC
- DATA; ENERGY LEVELS; ESTERS; EVEN-ODD NUCLEI; EXCITED STATES; INFORMATION; ISOTOPES; LIGHT NUCLEI; MAGNETIC RESONANCE; NUCLEI; NUMERICAL DATA; ORGANIC ACIDS; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; OXYGEN ISOTOPES; RESONANCE; SPECTRA; STABLE ISOTOPES