A task-specific ionic liquid of 1-(4-butylamino)-3-ethyl imidazolium tetrafluoroborate for capturing CO2

Ionic liquids (ils) of 1-(4-butylamino)-3-ethyl imidazolium([baeim]+) tetrafluoroborate ([bf4]-) for capturing co2 were systematically studied at b3lyp/6-311++g** and mp2/6- 311++g** level. two stable ils and two molecular complexes from the reactions of those ils and co2 were optimized with no imaginary frequencies,their energies were corrected by zero-point energy (zpe) and basis set superposition error (bsse). the results show that the interactions between ion-pair are mainly displayed as hydrogen bonds (hbs),the interaction energies between [baeim]+ and[bf4]- are greater than -318kj/mol,which are far beyond those of hbs. the natural bond orbital (nbo) and atom in molecular (aim) investigations show that the interactions are reinforced by charge dispersion and charge redistribution of ion-pair. the ils capturing co2 belong to physical absorption,the molar absorption ratio is 1:1,the absorption energies are about -20kj/mol,and thus the il may have a mild regeneration condition when desorbed from il-co2 theoretically.