Fast ion beam laser spectroscopy of N2O: Effects of orbital angular momentum and vibrational anharmonicity

Fast ion beam laser spectroscopy has been used to study the à 2 Σ + - [Xtilde] 2 Π transition of N 2 O + under high resolution. Molecular constants are obtained for several spin-vibronic states, including for the first time levels associated with the [Xtilde] 2 Π, v 2 = 2 manifold. These data are interpreted in detail in terms of a large-amplitude bending hamiltonian which allows for the effects of orbital angular momentum, spin-orbit coupling and vibrational anharmonicity associated with the bending motion. The spin-vibronic levels of the isoelectronic CO + 2 ion observed by Frye and Sears using diode laser spectroscopy are interpreted in an analogous manner.