The structure of Co+·OCO

Rotationally-resolved resonant photodissociation of isolated Co·OCO+ ions has been observed for the first time. Analysis of low energy A 3Φ4←X 3Δ3 and a 1Δ2←X 3Δ3 electronic transitions confirm the linear geometry for at least these three electronic states of the complex. The zero-point level of the ground 3Δ3 state exhibits a rotational constant of 0.05699±0.0005 cm−1 consistent with a center-to-center distance between the metal atom and the ligand (the Co+–C distance) of 3.17±0.01 Å. This experimental result agrees completely with recent ab initio predictions of the ground-state geometry of this molecule.