The ground and charge-transfer excited states of CoO+

The rotationally resolved, resonant photodissociation spectrum of CoO+ has been obtained for the first time. Transitions from the ground state to two excited electronic states are observed, 5Φ5−5Δ4 and 5Π3−5Δ4 with electronic origins (T00) at 16 713±10 cm−1 and 17 588±10 cm−1, respectively. The zero point rotational constant of the 5Δ4 ground state of CoO+ is found to be B0″=0.492±0.006 cm−1, resulting in an experimental bond length of r0″=1.65±0.01 Å. The excited states have longer bond lengths (r0′=1.86±0.01 Å) consistent with the charge transfer nature of the transition. These results are compared with ab initio predictions.