High-resolution laser-rf spectroscopy on the [formula omitted] system of lodine oxide (IO)

Abstract

The rotational spectra of the vibrationa bands 2-0, 2-1, and 2-2 of the A 2Π 3 2 -X 2Π 3 2 system of the IO radical have been studied at high resolution by molecular-beam laser-excitation spectroscopy. The hyperfine structure could be resolved for the lowest rotational levels and the hyperfine constants eQq 1 and a + ( 1 2 )(b + c) have been determined for both the excited and ground states. Hyperfine splittings within rotational levels of the ground vibrational X 2Π 3 2 state have been studied by a new spectroscopic method: microwave optical double resonance on a state-selected beam. The hyperfine constants eQq 2 and b − C I ( λ − 2) of the v = 0, X 2Π 3 2 state could be deduced as well. The widths of the rotational levels in the excited v = 2, A 2Π 3 2 state have been determined. Apart from the vibrationally dependent predissociation, a predissociation which depends on the rotational state has been observed.