A method for separating a selected substance from a mixture, comprising: adding to a mixture comprising a selected substance that is water-immiscible a compound of formula: wherein the compound of formula is a water-immiscible liquid; where R 5, R 6, and R 7 are independently H; a substituted or unsubstituted C 1 to C 10 alkyl group that is linear, branched, or cyclic; a substituted or unsubstituted C n Si m group where n and m are independently a number from 0 to 10 and n + m is a number from 1 to 10; a substituted or unsubstituted C 5 to C 10 aryl group; or a substituted or unsubstituted heteroaryl group having 4 to 10 atoms in the aromatic ring; wherein, optionally, any combination of R 5, R 6, and R 7, taken together with the nitrogen atom to which they are attached, are joined to form a heterocyclic ring; wherein a substituent is independently alkyl, alkenyl, alkynyl, aryl, aryl halide, heteroaryl, non-aromatic ring, Si(alkyl) 3, Si(alkoxy) 3, halo, alkoxy, amino, ester, amide, thioether, alkylcarbonate, phosphine, thioester, or a combination thereof; allowing the compound to solubilize the selected substance; optionally isolating waste solid(s) from the mixture; contacting the mixture with water and CO 2 thereby converting the compound to a salt; allowing the mixture to separate into two distinct phases; and separating the two distinct phases to provide an isolated aqueous phase comprising the salt and an isolated non-aqueous phase comprising the selected substance; wherein the selected substance is not reactive with the compound, CO 2, or a combination thereof; the method further comprising: removing CO 2 from the isolated aqueous phase to reform the water-immiscible compound of formula; and isolating the compound. adding to a mixture comprising a selected substance that is water-immiscible a compound of formula: wherein the compound of formula is a water-immiscible liquid; where R 5, R 6, and R 7 are independently H; a substituted or unsubstituted C 1 to C 10 alkyl group that is linear, branched, or cyclic; a substituted or unsubstituted C n Si m group where n and m are independently a number from 0 to 10 and n + m is a number from 1 to 10; a substituted or unsubstituted C 5 to C 10 aryl group; or a substituted or unsubstituted heteroaryl group having 4 to 10 atoms in the aromatic ring; wherein, optionally, any combination of R 5, R 6, and R 7, taken together with the nitrogen atom to which they are attached, are joined to form a heterocyclic ring; wherein a substituent is independently alkyl, alkenyl, alkynyl, aryl, aryl halide, heteroaryl, non-aromatic ring, Si(alkyl) 3, Si(alkoxy) 3, halo, alkoxy, amino, ester, amide, thioether, alkylcarbonate, phosphine, thioester, or a combination thereof; wherein the compound of formula is a water-immiscible liquid; where R 5, R 6, and R 7 are independently H; a substituted or unsubstituted C 1 to C 10 alkyl group that is linear, branched, or cyclic; a substituted or unsubstituted C n Si m group where n and m are independently a number from 0 to 10 and n + m is a number from 1 to 10; a substituted or unsubstituted C 5 to C 10 aryl group; or a substituted or unsubstituted heteroaryl group having 4 to 10 atoms in the aromatic ring; wherein, optionally, any combination of R 5, R 6, and R 7, taken together with the nitrogen atom to which they are attached, are joined to form a heterocyclic ring; wherein a substituent is independently alkyl, alkenyl, alkynyl, aryl, aryl halide, heteroaryl, non-aromatic ring, Si(alkyl) 3, Si(alkoxy) 3, halo, alkoxy, amino, ester, amide, thioether, alkylcarbonate, phosphine, thioester, or a combination thereof; allowing the compound to solubilize the selected substance; optionally isolating waste solid(s) from the mixture; contacting the mixture with water and CO 2 thereby converting the compound to a salt; allowing the mixture to separate into two distinct phases; and separating the two distinct phases to provide an isolated aqueous phase comprising the salt and an isolated non-aqueous phase comprising the selected substance; wherein the selected substance is not reactive with the compound, CO 2, or a combination thereof; the method further comprising: removing CO 2 from the isolated aqueous phase to reform the water-immiscible compound of formula; and isolating the compound. removing CO 2 from the isolated aqueous phase to reform the water-immiscible compound of formula; and isolating the compound.