The NO(X2Π)–Ne complex. I. IR-REMPI double resonance spectroscopy

Abstract

The rotationally resolved infrared spectrum of the NO–Ne complex associated with the first overtone transition in NO(X2Π) is measured in an IR-UV double resonance experiment. (2+1) resonance enhanced multiphoton ionization (REMPI) involving the Rydberg states E2Σ, F2Δ, and H2Σ,H′2Π is used to detect the infrared absorption. In the complex, the NO overtone transition is located at 3724.02 cm−1, i.e., it is blueshifted by 0.17 cm−1 from the transition in the monomer. Three other bands detected at frequencies 3727.85, 3732.56, and 3739.20 cm−1 are assigned to combination bands involving different intermolecular bend-stretch vibrations. The rotational structure of the observed bands is consistent with a near T-shaped complex. Details of the rotational structure resemble the spectrum of a symmetric top subject to weak electronic interactions causing a Stark-type and P-type doubling of the rotational levels.