Accession Number : AD0474595


Title :   NUCLEAR MAGNETIC RESONANCE STUDIES OF SOLVENT EFFECTS ON THE HINDERED INTERNAL ROTATION IN N, N-DISUBSTITUTED AMIDES HIGHER ALKYL AMIDES.


Descriptive Note : Technical documentary rept.,


Corporate Author : AEROSPACE CORP EL SEGUNDO CA LAB OPERATIONS


Personal Author(s) : Whittaker, A G ; Siegel, Seymour


Report Date : Sep 1965


Pagination or Media Count : 37


Abstract : The temperature dependence of the chemical shifts due to hindered internal rotation was measured for diethylformamide, diethylacetamide, diisopropylformamide, diisopropylacetamide and for solutions of these molecules in various solvents. In all cases, the chemical shifts showed unusual behavior. Conventional methods coupled with certain approximations were used to calculate activation energies as estimates for the rotational barrier to the internal rotation about the N-CO bond. These values were found to lie in the range of 5 to 26 kcal/mole. However, it is difficult to determine the real significance of these numbers; the behavior of the chemical shifts was such that no underlying concepts could be developed that would correlate the observed results except for the conclusion that the solvent plays a dominant role in the relationship between chemical shift and temperature. (Author)


Descriptors :   *AMIDES , NUCLEAR MAGNETIC RESONANCE , SOLVATION , MOLECULAR ROTATION , FORMAMIDES , ALKENES , HEAT OF ACTIVATION , TEMPERATURE , EXPERIMENTAL DATA , MEASUREMENT


Subject Categories : Atomic and Molecular Physics and Spectroscopy


Distribution Statement : APPROVED FOR PUBLIC RELEASE