THE CONFORMATION OF N-NITROSO-N-METHYLANILINE FROM MICROWAVE SPECTROSCOPY

Article abstract of DOI:10.1016/0022-2860(87)87057-6

The low resolution microwave spectrum of N-nitroso-N-methylaniline shows only one series of μ_a R-branch bands.The value of B + C = 1584.6 MHz is consistent with this being the rotamer in which the benzene ring is exo to the nitroso group.The high resolution microwave spectra of the normal, CD3 and two meta-D species show conclusively that this rotamer has a non-planar heavy atom skeleton.The rotational constants, the quantity Δ_c (= I_a + I_b - I_c) and the substitution coordinates are well reproduced by a molecular model based on the structures of aniline and N,N-dimethylnitrosamine in which the plane of the benzene ring is twisted by <*> 30 deg relative to the heavy atom plane of the rest of the molecule.