Radical nitrogen-based molecules that can act to facilitate nitrosylation reactions; reactive nitrogen species include dioxidonitrogen(\(\ce{^{.}}\)) (nitrogen dioxide, nitryl radical) \(\ce{NO^{.}}\), oxidonitrogen(\(\ce{^{.}}\)) (nitrogen monoxide, nitrosyl radical) \(\ce{NO^{.}}\) oxidonitrogen(1+) (nitrosyl cation) \(\ce{NO^{+}}\), hydroxyoxidonitrogen (nitrous acid) \(\ce{HNO2}\), and oxidonitrate(1-) \(\ce{NO^{-}}\).