15min:

M. R. FRANCE, S. H. PULLINS AND M. A. DUNCAN, Department of Chemistry, University of Georgia, Athens, GA 30602.

Ca⁺-C₂H₂ is produced in a molecular beam and studied with mass-selected photodissociation spectroscopy. A spectrum with sharp vibrational and rotational structure is measured near the Ca⁺ (²P-²S) transition. Ca⁺-C₂H₂ has a -complex structure with a Ca⁺-C₂H₂ bond distance of r₀''=2.80 Å, a vibrational frequency (Ca⁺-C₂H₂ stretch) of G_1/2'' = 169 cm^-1 and a dissociation energy of D₀'' = 18.6 kcal/mol. This is the first determination of these properties for an isolated metal cation -complex.