Early Stage Solvation of Protonated Methanol by Carbon Dioxide

• Published in: Chinese journal of chemical physics 2015-08, Vol.28 (4), p.501-508
• Main Authors: Zhao, Zhi, Kong, Xiang-tao, Lei, Xin, Zhang, Bing-bing, Zhao, Ji-jun, Jiang, Ling
• Format: Article
• Language: English
• ISSN: 1674-0068; 2327-2244
• DOI: 10.1063/1674-0068/28/cjcp1507146

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 first solvation shell of the OH groups is completed at n=3 or 4. Besides hydrogen-bond interaction, the CCO2 ⋯ OCO2 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 afford 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.