The Electronic Structures and Electronic Spectra of Some Aliphatic Nitroso Compounds

The electronic structures and electronic spectra of 1-chloro-1-nitrosocyclohexane, nitrosyl chloride, methyl nitrite and dimethylnitrosoamine were studied by making molecular orbital calculations and by measuring the electronic absorption spectra. Concerning 1-chloro-1-nitrosocyclohexane, the n→π* and π→π* bands were observed at 650 and 160 mμ respectively. The conjugation effect of electron donors such as Cl, OCH3 and N(CH3)2 upon the electronic spectrum of the nitroso group was studied. The intramolecular charge-transfer bands characteristic of the donor-acceptor interaction were found at 190, 210 and 230 mμ for nitrosyl chloride, methyl nitrite and N,N-dimethylnitrosoamine respectively. This shows that the intramolecular charge-transfer bands appear at longer wavelengths in the order of the increasing ability of the electron donors, Cl<OCH3<N(CH3)2. On the other hand, the n→π* bands shift to shorter wavelengths in the same order.