In chemistry, the amino radical, , also known as the aminyl radical or azanyl radical, is the neutral form of the amide ion (). Aminyl radicals are highly reactive and consequently short-lived, like most radicals; however, they form an important part of nitrogen chemistry. In sufficiently high concentration, amino radicals dimerise to form hydrazine.  While  as a functional group is common in nature, forming a part of many compounds (e.g. the phenethylamines), the radical cannot be isolated in its free form.