Early Stage Solvation of Protonated Methanol by Carbon Dioxide (cited: 1)

The solvation of protonated methanol by carbon dioxide has been studied via a cluster model. Quantum chemical calculations of the H⁺(CH₃OH)(CO₂)_n⁺(n=1-7) clusters indicate that the rst solvation shell of the OH groups is completed at n=3 or 4. Besides hydrogen-bond interaction, the C_CO2…O_CO2 intermolecular interaction is also responsible for the stabilization of the larger clusters. The transfer of the proton from methanol onto CO₂ with the formation of the OCOH⁺ moiety might be unfavorable in the early stage of solvation process. Simulated IR spectra reveal that vibrational frequencies of free O-H stretching, hydrogen-bonded O-H stretching, and O-C-O stretching of CO₂ unit a ord the sensitive probe for exploring the solvation of protonated methanol by carbon dioxide. IR spectra for the H⁺(CH₃OH)(CO₂)_n⁺(n=1-7) clusters could be readily measured by the infrared photodissociation technique and thus provide useful information for the understanding of solvation processes.