The Cation H ₁₃ O ₆ ⁺ : A Short, Symmetric Hydrogen Bond

Abstract

The H 13 O 6 + ion has been found to exist as a discrete entity, forming when the cage compound [(C 9 H 18 ) 3 (NH) 2 Cl] + Cl - is crystallized from hydrochloric acid solution. The aquo-cation H 13 O 6 + has crystallographic symmetry 2/ m ( C 2 h ). The central bond O⋅⋅H⋅⋅O is symmetric. with a length of 2.39 ± 0.02 angstroms; the four outer hydrogen bonds are asymmetric. with a length of 2.52 ± 0.01 angstroms. The cage compound consists of a chloride ion encapsulated within a triply bridged diammonium species. with hydrogen bond distances N(H)⋅⋅Cl of 3.10 ± 0.01 angstroms.