
TY  - JOUR
A1  - Yokoyama, T 
T1  - Resonance and solvent effects on absorption spectra of 2-nitroaniline derivatives
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1976
VL  - 29
IS  - 7
SP  - 1469
EP  - 1475
KW  - 
UR  - https://doi.org/10.1071/CH9761469 
N2  - Spectral data for N-methyl-2-nitroaniline correlate well with those for N,N-dimethyl-2-nitroaniline in non-hydrogen-bonding, hydrogen-bond-accepting and amphiprotic alcoholic solvents. This same pattern has been reported for N-methyl-2-nitro-p-toluidine. These results indicate that these N-methyl compounds have no hydrogen bonds with any of the solvents studied and intramolecular hydrogen bonding predominates. In the N.M.R. spectra of such amines, long-range coupling between the H5 (ring) and N-H protons is not necessarily evidence for intramolecular hydrogen bonding.  +M substituents at the 4-position increase the twist of the dimethylamino and 2-nitro groups and enhance the C1 &#8594; C2 transition, an effect which follows the order of +M abilities of the 4-substituents. 
ER  -

