Knowledge Bank

Vibrational levels near the dissociation limit of the $A3\Pi (1)$ electronic state of $135Cl$ have been studied using fluorescence excitation techniques. By using a single mode ultra high resolution ring laser and a collimated molecular beam, the hyperfine structure due to both Iodine $(I=5/2)$ and Chlorine $(I=3/2)$ nuclel has been resolved. The hyperfine structure for the $\nu \prime =19,24$ and 29 vibrational levels will be discussed along with changes in the rotational (B), electric quadrupole ($eQq0,eQq2$ for both I and Cl), and magnetic hyperfine (a) constants as the molecule approaches dissociation. In addition, observed heterogeneous (state mixing) perturbations in the spectra of these high vibrational levels will be discussed.