DFT Study on CO2 Absorption by a New Generation of Ionic Liquids

New generation of ionic liquids (ILs) based on 1,8-diazobicylo [5,4,0] undec-7-ene, (DBU), is applied as the solvent in organic reactions [1]. In this work, by using a theoretical procedure, we investigated four different DBU-based ILs consisting of DBU as a cation and four different imidazole derivatives as the anions. The results showed that the bond length of the N-C decreases at the transition state, showing that CO2 is absorbed by the ILs. Natural bond orbital (NBO) analysis showed a strong charge transfer between the N atom of the imidazole anion and C atom of the CO2, confirming CO2 absorption. On the basis of the results, DBU superbase and DBU derivative-based ILs are good candidates for CO2 absorption because of high basicity. Finally, DBU based ILs have an excellent ability for CO2 capturing, which is important in chemical industries.

کلیدواژه ها:

Ionic liquid ، Imidazole ، theoratical procedure ، charge transfer ، CO2 capture