Microwave spectrum of selenium dioxide

Abstract

E.A.Alekseev, O.I.Baskakov, S.F.DyubkoInstitute ofRadio Astronomy ofthe Ukrainian Academy of Sciences,4 Krasnoznamennaya St., 3 10002 Kharkov, UKRAINEABSTRACTBetween 70 and 500 GHz a number of transitions of 765e02, 775e02, 785e02, 80SeO2, and 825e02 in the ground andexcited v21 vibrational states have been measured. Transitions of 80SeO2 in the excited v2=2 state and of 74SeO2 in theground state have been measured as well. Greatly improved sets of the parameters of A-reduced Watson's Hamiltonianhave been obtained in the jr representation.1. INTRODUCTIONBent triatomic molecules have been an object of extensive spectroscopic studies for a long time. Very rich data havebeen obtained on the 502 molecule and its isotopic species in the ground and some excited vibrational states15.Bycontrast, the rotational spectrum of selenium dioxide molecule was studied previously by Takeo et al. only. Between 8and 36 GHz they have measured about 90 rotational transitions belonging to the ground and some excited vibrationalstates of 5 the most abundant Se02 isotopic species (76SeO2, 77SeO2, 785e02, 805e02, and 825e02). An accuracy of theirmeasurements was of about The rotational constants for isotopic species in the investigated vibrational stateshave been derived from experimental data. Quartic centrifugal distortion constants were obtained for the ground state of78SeO2 and 80SeO2 only. The equilibrium structure of selenium dioxide and its force field have been calculated as well.Recently, a detail study of the 805e02 ground vibrational state have been carried out8 .