Optical-optical double-resonance spectroscopic study of four ion-pair states of ClF and identification of the ClF(A 3Π1) valence state

Abstract

Four of the six ion-pair states of ClF that correlate to Cl+(3PJ) and F−(1S0), the E(0+,3P2), f(0+,3P0), β(1,3P2), and G(1,3P1) states, have been identified by sequential, two-photon excitation via the ClF(B 3Π0+) valence state. The Ω=1 states, β and G, were studied by selection of rotational levels of the B 3Π0+ state that are perturbed by ClF(A 3Π1). Spectroscopic data from laser excitation and fluorescence spectra permit the assignment of vibrational energies and rotational constants to 30 levels. These four ion-pair states exhibit extensive homogeneous and heterogeneous interactions, and neither the vibrational energy nor the rotational constants are regular with increasing vibrational quantum number. The vibrational and rotational constants of the A 3Π1 state were identified from the low resolution ClF[β(1)−A 3Π1] emission spectra, and the dissociation limits of the A 3Π1 and B 3Π0+ states are compared. The dissociation energy of ClF(X) is confirmed to be 21 110 cm−1. Some qualitative information also was obtained about the D′(2,3P2) and A′ 3Π2 states of ClF.