The hydrogen bond energies of the bihalide ions XHX − and YHX −

Abstract

Experimental measurements of the gas phase ion equilibria X − + HX = XHX − , X − (HX) n−1 + HX = X − (HX) n , and X − + HY = XHY where X, Y = Cl, Br, I, with a high pressure mass spectrometer, combined with the recent determination of F − + HF = FHF − by Larson and McMahon, provide a very complete set of hydrogen bond dissociation enthalpies and free energies for the hydrogen bihalide ions. The bond energy trends in the different XHX − and XHY − are discussed. The data can be used also for the evaluation of lattice energies of salts containing the bihalide ions and for determinations of the solvation energies of these ions.