Rotational Structure of a Super-Excited State of the NO Molecule Revealed by OODR-Multiphoton Laser Spectroscopy

Abstract

The optical-optical double resonance time of flight (OODR-TOF) spectroscopy technique was employed to examine the 65 000-66 500 cm -1 region of the nitric oxide spectrum. In this region, we detected the following three electronic states: E 2 Σ + (ν = 2) (Rydberg state), B 2 Π (ν = 23) (valence state), and L 2 Π (ν = 4) (valence state). The rotational structure analysis of an unexpected band in the red part of the spectra revealed the presence of a new super-excited 2 Σ + Rydberg state at ~13.3 eV, which was populated through a three-photon transition from the intermediate A 2 Σ + (ν = 0) state. This super-excited state converges to the NO (a 3 Σ + ) ionic state with electronic configuration (1σ) 2 (2σ) 2 (3σ) 2 (4σ) 2 (5σ) 2 (1π) 3 (2π) 1 (3sσ) 1 .