Structural and spectral consequences of ion-pairing. VI. BO^-₂Li⁺ and BO^-₂Na⁺

Ab initio molecular orbital calculations have been carried out to investigate the interactions between lithium and sodium ions with BO^-₂ and to determine the nature of the structure of ion-pairs of BO^-₂Li⁺ and BO^-₂Na⁺. The lithium metaborate has one stable configuration of C_∞h symmetry and is linear. The sodium metaborate ion-pair has two stable configurations of C_∞h and C_2v symmetry. The C_∞h linear structure is the most stable form. Vibrational frequencies of all the ion-pair complexes have been determined along with isotopic shifts. Isotopic frequency shift patterns which are unique to the type of structure are discussed.