Multi-Molar Absorption of CO2 by the Activation of Carboxylate Groups in Amino Acid Ionic Liquids

• Published in: Angewandte Chemie International Edition Vol. 55; no. 25; pp. 7166 - 7170
• Main Authors: Chen, Feng-Feng, Huang, Kuan, Zhou, Yan, Tian, Zi-Qi, Zhu, Xiang, Tao, Duan-Jian, Jiang, De-en, Dai, Sheng
• Format: Journal Article
• Language: English
• Published: Germany Blackwell Publishing Ltd 13.06.2016; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Absorption; Activation; Amino acids; Anions; Carbon dioxide; carboxylate group activation; CO2 capture; Ionic liquids; Ions; Liquids; Mathematical analysis; multiple site interactions; Quantum chemistry; Solvents; Spectroscopy; carboxylate group activation; CO2 capture; ionic liquids; multiple site interactions; amino acids
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201602919

A new strategy for multi‐molar absorption of CO2 is reported based on activating a carboxylate group in amino acid ionic liquids. It was illustrated that introducing an electron‐withdrawing site to amino acid anions could reduce the negative inductive effect of the amino group while simultaneously activating the carboxylate group to interact with CO2 very efficiently. An extremely high absorption capacity of CO2 (up to 1.69 mol mol−1) in aminopolycarboxylate‐based amino acid ionic liquids was thus achieved. The evidence of spectroscopic investigations and quantum‐chemical calculations confirmed the interactions between two kinds of sites in the anion and CO2 that resulted in superior CO2 capacities. My mate, carboxylate: multi‐molar absorption of CO2 (up to 1.69 mol mol−1) is possible using aminopolycarboxylate‐based ionic liquids (APC‐ILs) by introducing an electron‐withdrawing site to reduce the negative inductive effect of the amino group while simultaneously activating the carboxylate group. The multiple‐site interactions between the anion of APC‐ILs and CO2 resulted in superior CO2 capacities.