Abstract: | The electronic absorption spectra of the A 1Π(u)←X 1Σ transition of CCN+ and CNC+ have been observed in a 5 K Ne matrix after mass selection of C2N+. CCN+ has the origin band at 462.0(2) nm. The vibrational structure with frequencies 1223(20) and 1725(20) cm−1 corresponds to the symmetric and antisymmetric stretching modes in the excited state. The origin band of CNC+ is observed at 325.7(2) nm, and the system shows extensive vibrational excitation. Calculations of the potential energy functions of CCN+ and CNC+ in their X 1Σ ground state and the A 1Π state of CCN+ followed by variational evaluation of the rovibronic energy levels allows the assignment of the observed spectra. These spectroscopic data open the way to gas‐phase studies of the astrophysically important C2N+ ions. |