Autodetachment spectroscopy of the aluminum oxide anion dipole bound state

The (1)Σ(+)←X(1)Σ(+) ground state to dipole bound state (DBS) electronic transition of AlO(-) has been studied by means of autodetachment spectroscopy. Vibrational and rotational molecular constants for AlO(-) have been determined for both the ground state (υ″ = 0, 1) and the excited DBS (υ' = 0, 1). These data provide an improved determination of the electron affinity for AlO (2.6110(7) eV) that is consistent with an earlier measurement. The electron binding energy of the DBS was found to be 52 ± 6 cm(-1). Experimental results are compared with the predictions from high level ab initio calculations.