Summary: ESTIMATION OF THE HYDROGEN­BOND LENGTHS TO
H 3 O + AND H 5 O +
2 IN LIQUID WATER
NOAM AGMON
Department of Physical Chemistry and the Fritz Haber Research Center,
The Hebrew University, Jerusalem 91904, Israel
ABSTRACT
Hydrogen­bond lengths to protonated water monomer and dimer in liquid
water are difficult to estimate from quantum chemistry calculations of pro­
tonated water clusters due to cluster size effects. It appears that bulk wa­
ter exhibits shorter hydrogen­bonds as compared with gas­phase hydrates.
Here the empirical Pauling­BEBO relation is used to correlate the inter­
molecular O \Delta \Delta \Delta H bond length with the intramolecular H--O bond length
at a common H­atom. Comparison of the correlation for clusters and bulk
water produces refined estimates for the bond lengths in question.
I. INTRODUCTION
In the past few decades, extensive computational work has been devoted to proto­
nated hydrates [1]. Their structure is relevant to small protonated water clusters in the
atmosphere and probably also to acidic aqueous solutions. With improvement in ab ini­
tio chemistry methodologies, it becomes clear that clusters corresponding to both H 3 O +

Source: Agmon, Noam - Institute of Chemistry, Hebrew University of Jerusalem

Collections: Chemistry