The Collaborative International Dictionary
n. (context chemistry English) The univalent radical and functional group -N=O
Nitroso refers to a functional group in organic chemistry which has the NO group attached to an organic moiety. As such, various nitroso groups can be categorized as C-nitroso compounds (e.g., nitrosoalkanes; R−N=O), S-nitroso compounds (nitrosothiols; RS−N=O), N-nitroso compounds (e.g., nitrosamines, RN(−R)−N=O), and O-nitroso compounds (alkyl nitrites; RO−N=O).
Nitrosyls are non-organic compounds containing the NO group, for example directly bound to the metal via the N atom, giving a metal–NO moiety. Alternatively, a nonmetal example is the common reagent nitrosyl chloride (Cl−N=O).
Nitric oxide is a stable radical, having an unpaired electron.