Nitroso compounds: group frequencies

The chapter opens with a number of general comments (I, II) and then moves to the section on nitroso compounds (II, B). These latter groups can lead to fairly complex spectra because isomerization (enolization) to oximes can occur (II, B4), and in the case of tertiary and aromatic systems dimerization is possible (II, B5). Nitrosoamines also tend to dimerize to give spectra that are consistent with the above assignments (II, D). Finally, there are a detailed discussions of nitro ( NO2 (III, A, B)) and nitrate (O NOa (III, C)) groups. Here the stretching frequencies are enormously intense and are often the most intense bands in the spectrum. 

The compound Fd oHibO NO was formed and was assumed to be a 5-covalent compound with the nitroso group attached to the metal ion, since the infrared spectrum showed a characteristic NO stretching frequency at 1656 cm-1 (66). 

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