Carbon dioxide removal and ionic liquid compounds useful therein

A method for the removal of CO2 from a gaseous mixture comprising contacting the gaseous mixture with one or more compounds represented by the structure of the following Formula I:

• Formula I
• wherein
• (a) Z is —(CH2)n—, wherein n is an integer from 2 to 12, or Z is —[(CH2)b—O]c—(CH2)d— wherein b and d are each independently integers from 1 to 4, and c is an integer from 1 to 8;
• (b) R2 and R3 are each independently H or a C1 to C6 straight-chain or branched alkyl group;
• (c) R4 is H, a C1 to C6 straight-chain or branched alkyl group, or —[(CH2)p—X]q—(CH2)r—Y—R6 wherein X and Y are each independently O or NR6, p and r are each independently an integer from 1 to 4, q is an integer from 0 to 8, and R6 is H or a C1 to C6 straight-chain or branched alkyl group;
• and
• (d) A− is an anion selected from the group consisting of levulinate, [BF4]−, [PF6]−, [SbF6]−, [CH3CO2]−, [HSO4]−, [CF3SO3]−, [HCF2CF2SO3]−, [CF3HFCCF2SO3]−, [CF3—OCFHCF2SO3]−, [CF3CF2OCFHCF2SO3]−, [CF3CF2CF2OCFHCF2SO3]−, [HCClFCF2SO3]−, [(CF3SO2)2N]−, [AlCl4]−, [CF3CO2]−, [NO3]−, [SO4]2−, Cl−, Br−, I−, and F−.