A novel functional ionic liquid for CO2 capture

A functional ionic liquid of Bromide 1-(4-butylamino)-3-methyl imidazolium (ILs) for capturing CO2 was investigated at B3LYP/ 6–311++G** level. Three geometry structures of ILs and three molecular complexes from ILs absorbing CO2 were optimized, and their energies were obtained which were corrected by zero point energy and basis sets superposition energy. The results show that the interactions between ion-pairs are mainly hydrogen bonds; and the hydrogen bond interactions energies are greater than −300KJ/mol, which are far beyond that of hydrogen bonds; and the interactions energies between ILs and CO2 are less than −11.0kJ/mol. And the comprehensive analysis implies that the reaction of ILs and CO2 are physical absorptions, the mole absorption ration is 1∶1.