JASON O. CLEVENGER, XING JIANG, SERGEY I. PANOV AND ROBERT W. FIELD, Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139.

Experimental results from our continuing study of the Rydberg states of Calcium Monochloride will be presented. Previously we have characterized the quantum defects and predissociation mechanisms of core-penetrating 2 Sigma+ states of CaCl in the n* = 3-7 region., Questions unanswered by this work propelled further studies of the low-n* region (n* = 3-5) by REMPI and ion-dip techniques, as this region is expected to be extensively predissociated by 2 Sigma+ and 2 Pi repulsive states. Interest in high-n* (n* > 15) Rydberg states of CaCl has also fueled further REMPI experiments near the first ionization threshold (48 491 cm-1). Studies of the low-n* region failed to reveal several predicted members of known core-penetrating 2 Sigma+ Rydberg series (n* = 0.16, 0.49, 0.68 2 Sigma+ and 0.30 2 Pi), while preliminary data for the high-n* region above the v+=0 IP indicate the presence of vibrationally autoionizing Rydberg states converging to v+>0 vibrational levels of the CaCl+ ion X 1 Sigma+ state. Analysis is ongoing.