Features of Protonation of the Simplest Weakly Basic Molecules, SO₂, CO, N₂O, CO₂, and Others by Solid Carborane Superacids

An experimental study on protonation of simple weakly basic molecules (L) by the strongest solid superacid, H(CHB₁₁F₁₁), showed that basicity of SO₂ is high enough (during attachment to the acidic H atoms at partial pressure of 1atm) to break the bridged H-bonds of the polymeric acid and to form a mixture of solid mono- LH⁺An^-, and disolvates, L-H⁺-L. With a decrease in the basicity of L=CO (via C), N₂O, and CO (via O), only proton monosolvates are formed, which approach L-H⁺-An^- species with convergence of the strengths of bridged H-bonds. The molecules with the weakest basicity, such as CO₂ and weaker, when attached to the proton, cannot break the bridged H-bond of the polymeric superacid, and the interaction stops at stage of physical adsorption. It is shown here that under the conditions of acid monomerization, it is possible to protonate such weak bases as CO₂, N₂, and Xe.