The ionization energy of the diazomethyl radical (HCNN)

The structure and vibrational frequencies of the HCNN radical and the HCNN+ cation have been calculated using ab initio methods. Both the lowest triplet and lowest singlet states of the cation have been determined. In the X̃ 3Σ− state the ion is linear, whereas it is bent in the ã 1A′ state. Using a complete basis set method, the ionization energy for the process yielding the X̃ 3Σ− state of the cation is calculated as 9.63±0.04 eV. That for the process yielding the ã 1A′ state of the cation is 10.33±0.04 eV.