The millimeter-wave spectrum of chlorine nitrate (ClONO2): the 3ν9 and ν7ν9 interacting dyad

The rotational spectrum of chlorine nitrate (ClONO2): The ν5/ν6ν9 dyad

“…The principal challenge to their analysis is the strong perturbation between the two states, which was found to affect rotational transitions with low values of the K a quantum number. The interactions between the states of the m 5 /m 6 m 9 dyad are different than those which we have reported previously for the m 7 /2m 9 [12] and the m 7 m 9 /3m 9 [13] dyads because the current states are of different symmetry and in the m 5 /m 6 m 9 dyad there is, therefore, no first order Fermi interaction to push the states apart. The v 5 = 1 state belongs to the A 0 and the (v 6 = 1, v 9 = 1) state to the A 00 representation of the C s symmetry group for the ClONO 2 molecule, so that Coriolis coupling between the two states is possible about both the a-and the b-inertial axes.…”

“…Several microwave studies have been done of the ground and m 9 states [1,10,11]. More recently, microwave work has also been reported on the lowest energy dyads of interacting vibrational states, including 2m 9 /m 7 [12] and 3m 9 /m 7 m 9 [12,13], and relations among the spectral constants and Fermi resonances of the several vibrational interactions were developed [14].…”

The rotational spectrum of chlorine nitrate (ClONO2) in the four lowest nν9 polyads

“…The pure rotation spectrum of chlorine nitrate has been investigated on many previous occasions [10][11][12][13][14][15][16][17]. The chlorine nitrate molecule has several low frequency vibrational modes such that, even for moderate vibrational energies of up to 650 cm À1 , there are already 14 different excited vibrational states, see Fig.…”

The millimeter-wave spectrum of chlorine nitrate (ClONO2): The ν6 vibrational state

“…that are coupled by strong perturbations. We have reported analyses of several of these [10][11][12][13]. There is also a less systematic perturbation that leads to the m 5 /m 6 m 9 dyad [14].…”