Theoretical Study of Cation/Ether Complexes:  Alkali Metal Cations with 1,2-Dimethoxyethane and 12-Crown-4

Hartree−Fock and second-order perturbation theory methods were used to determine structures and binding enthalpies of complexes formed from a single alkali metal cation (Li + through Cs + ) and one or two 1,2-dimethoxyethane ligands or 12-crown-4. These calculations employed multiple basis sets in order to determine the sensitivity of the results to the completeness in the one-particle basis. The results are compared with recently reported collision-induced dissociation experimental findings. In general, good agreement was found between the experimental and theoretical bond dissociation enthalpies, although for the heavier cations discrepancies of as much as 14 kcal/mol or more were uncovered. Possible reasons for these anomalies are discussed.