 The high energy electronic state, 2A1, has the two electrons in the "p"-orbital and the unpaired electron in the sp2 orbital (σ type orbital).Nitrogen centered compounds, such as amines, are nucleophilic in nature, hence, this character is also seen in amino radicals and can be considered to be nucleophilic species.The amino radical only exhibits a very low optical absorption in the visible region (λmax 530 nm, εmax 81 M−1 s−1), while its absorption in the UV (<260 nm) is similar to that of OH.