Q51 ans d
Sarthak Basak last edited by Sarthak Basak
The hydroxonium ion binds strongly to another water molecule in two possible manners (in a vacuum). Opposite are shown the two H5O2+ dihydronium ions with closely matched energies, where the proton is asymmetrically (top) or symmetrically (bottom) centered between the O-atoms.
The asymmetric structure (top left) of H5O2+ is found to be more stable. It has a strong hydrogen bond.
When the extra proton is shared equally between more than one water molecule, the approximate structure can be deduced from a consideration of the resonance structures. For example, the two shared protons in H7O3+ give rise to bond lengths halfway between those in (H2O)2 and H5O2+.
Global geometry optimizations of the hydroxide hydrate anion (H3O2)− are performed to determine its structure. An asymmetric hydrogen bond is found, while a symmetric structure results when correlation is included. Comparisons are made to previous theoretical studies of (H3O2)−, and also to recent x‐ray crystallography results.