| Abstract
| - A pentagonal ring is suggested as the basic structural unit ofHCl(H2O)6 and(HCl)2(H2O)6 in solution.Modeledafter the X-ray structure of a cagedH13O6+ compound, it containsbridged H5O2+ andCl- ions, each with acoordination number around four. In the most concentrated HClsolutions, one of the ligands solvating Cl-is HCl, giving rise to a bichloride moiety. The proposed structureexplains qualitatively the stoichiometry,ion mobility, (IR, Raman) spectroscopy and (X-ray, neutron) diffractiondata of concentrated HCl solutionsand provides a semiquantitative fit to the X-ray radial distributionfunction. The ring structure is a likelycandidate for the structure of protonated HCl clusters in the gas phaseand for the contact ion-pair formedfollowing HCl dissociation in solution.
|
