Synthesis and characterization of amide-Functionalized analogues of glycine-betaine based ionic liquids and an exemplified use for the separation of copper(II) and cobalt(II)

Abstract

ABSTRACT Novel series of amide functionalized analogues of glycine-betaine-based ionic liquids (AGB-ILs), namely, [N,N,N-tri(n-butyl)(2-aminoalkyl-2-oxoethyl)]ammonium (alkyl = n-butyl, and n-octyl) associated with tetrafluoroborate (BF4 −), hexafluorophosphate (PF6 −), bis(trifluorosulfonyl)imide (Tf2N−), dicyanamide (Dca−), 4-chlorosalicylate (ClSal−) and saccharinate (Sac−) anions have been synthesized and fully characterized by spectroscopic methods (IR, 1H and 13C NMR) and elemental analysis. The alkyl chain length of the organic cation and the chemical nature of inorganic or organic anion on physicochemical properties such as melting point, glass transition and decomposition temperatures, and viscosity have been described. To determine the sensitivity of Dca ligand to pH, the effect of the pH on the extraction properties of aqueous Cu2+ and Co2+ ions has been investigated in the pH range 1 to 5.