Enthalpy of Solution of Amino Acid Ionic Liquid 1-Butyl-3-methylimidazolium Glycine
journal contributionposted on 12.06.2008, 00:00 by Wei Guan, Wei-Feng Xue, Nan Li, Jing Tong
A new novel amino acid ionic liquid [C4mim][Gly] (1-butyl-3-methylimidazolium glicine) was prepared by the neutralization method. The molar enthalpies of solution, ΔsolHm(wc), of [C4mim][Gly] with various amounts of water and with various molalities were measured by the solution−reaction isoperibol calorimeter at (298.15 ± 0.01) K. According to Archer’s method, the standard molar enthalpies of solution of [C4mim][Gly] with known amounts of water, ΔsolH0m(wc), were obtained. To eliminate the effect of the small amount of water in [C4mim][Gly], a linear fitting of ΔsolH0m(wc) against water content was carried out so that a good straight line was obtained, and the intercept was the standard molar enthalpy of solution of [C4mim][Gly] without water, ΔsolH0m = (−46.02 ± 0.19) kJ·mol−1. Using Glasser’s lattice energy theory, the hydration enthalpy of the glycine anion [Gly]− was estimated.