Determination of potential energy curves for ground and metastable excited state transition metal ions interacting with helium and neon using electronic state chromatography

Abstract

Reduced zero field mobilities of Cr+, Co+, and Ni+ in their ground state configuration (3dn) and their metastable excited state configuration (3dn−14s1) have been measured in He and Ne as a function of temperature. Parameters for a n−6−4 interaction potential are obtained by fitting the mobility vs temperature curve. Bond dissociation energies, vibrational frequencies, and equilibrium bond lengths are extracted from these curves and compared with data from traditional equilibrium measurements and ab initio theory. Dramatic changes in bonding are observed for the 3dn and 3dn−14s1 configurations; the 3dn configuration yielding very much stronger bonds and very much shorter equilibrium bond lengths than the 3dn−14s1 configuration. The presence of multiple potential curves in the interaction of Co+(3F,3d8) and Ni+(2D,3d9) with He/Ne make interpretation of the ground state mobility data ambiguous. The analysis of each system is discussed in some detail.