Bond valence <i>vs</i> bond length in O...O hydrogen bonds

Abstract

The total valence of the bonds between acceptors and the H atoms bonded to a water molecule (s d) is taken equal to the bond valence (st) received by the donor 0 atom from coordination bonds. For an OH- group, s d = sr-l. Plots of the bond valence s for H...O bonds as functions of O...O, H...O and O-H distances are fitted with the function s = (R/Ro)-b+ k. The most reliable fitting is obtained for s vs O...O; a minimum value of O...O ~_2.55 A for the hydrogen bonds donated by a water molecule is predicted. Similar curves from the literature are compared and discussed.