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. |