Predissociations of the C¹²o and C¹³o Molecules

The Ångström bands of C 12 O and C 13 O have been photographed with a high dispersion spectrograph and the predissociations previously reported in these bands have been re-examined. The predissociations provide good evidence that C 12 O has a dissociation limit 89595 ± 30 cm. −1 above the ν = 0 level of the ground state. The fourth positive (A 1 Π − X 1 Σ) bands have been re-examined and it has been shown that, contrary to earlier reports, there is no evidence for predissociation in the A 1 Π state.