| High-resolution photodissociation spectroscopy has been used to characterize singly charged metal-ligand binary ions in the visible region. Molecular ions of interest (e.g. (M{dollar}sp+{dollar}-L) complexes, where M{dollar}sp+{dollar} is either Ca{dollar}sp+{dollar}, Co{dollar}sp+{dollar}, V{dollar}sp+{dollar}, Nb{dollar}sp+{dollar}, Ta{dollar}sp+{dollar} or Fe{dollar}sp+{dollar} with Ar, Kr, Xe, CO and CO{dollar}sb2{dollar} 'ligands') and metal diatomic ions (Ni{dollar}sb2sp+{dollar} and CrFe{dollar}sp+{dollar}), generated in a laser-driven-plasma supersonic expansion ion source, are mass-selected prior to photo-interrogation with tunable laser light. Vibronic analysis of the spectra for various molecular ions provide their spectroscopic constants; vibrational frequencies and anharmonicities of the excited states are obtained.; For diatomic metal cation - (rare-gas) complexes, band systems with long progressions (that lead to convergence) are analyzed via LeRoy-Bernstein (LB) protocol to provide accurate dissociation limits for the probed excited states. From this analysis both ground and excited states well depths are then determined. Each molecular ion has a unique LB slope which depends on both the polarizability of the rare gas and the reduced mass. Thus, from several examples of M{dollar}sp+{dollar}(Ar) systems, the effective electric-dipole polarizability volume of argon (derived from LB slopes) in a field of a point charge yields a value (1.48 {dollar}pm{dollar} 0.1 A{dollar}sp3{dollar}) slightly less than the accepted literature 'bulk' value (1.64 A{dollar}sp3{dollar}).; Trends in the binding energies of transition metal cation - ligand systems and calcium cation - (rare gas) complexes are discussed. Comparisons between experimental observations and theoretical predictions indicate that calculations estimate parallel trends to experiment but consistently underestimate the true binding energies by {dollar}approx{dollar}20%. |
