Negative ion photoelectron spectroscopy of the heteronuclear alkali-metal dimer and trimer anions: NaK −, KRb −, RbCs −, KCs −, Na 2K −, and K 2Cs −

Abstract

Negative ion photoelectron spectra are reported for the heteronuclear alkali dimer and trimer anions, NaK −, KRb −, KCs −, RbCs −, Na 2K −, and K 2Cs − at 488 nm. In addition to assigning all of the electronic transitions observed in the mixed dimer anion spectra, vertical detachment energies, adiabatic electron affinities, and dimer anion dissociation energies have also been determined. A linear correlation between mixed dimer EA as and α M*/ r 2 M*M (α M* = the more electropositive alkali atom's polarizability) confirms the presence of ionic character in heteronuclear alkali dimers. Also, vertical detachment energies and adiabatic electron affinities are reported for the trimer systems.