Mechanism of azeotrope elimination in the ethyl propionate-ethanol system using ionic liquid HMIMOAc as an entrainer:
Shuyan Liu1, Xiuyu Du1, Kuan Ji1
1Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, China. zhouyu@qdu.edu.cn.
Abstract:
Ionic liquids (ILs) are highly effective entrainers for extractive distillation of azeotropes, owing to their unique physicochemical properties. However, the intrinsic molecular mechanisms underlying the role of ILs in the azeotropic separation process remain insufficiently understood. To investigate the intrinsic causes of azeotrope elimination by ILs, the study focused on the v(O-D) region of ethanol employing both experimental and theoretical methods to investigate the microstructural properties of the ethyl propionate (EP)-ethanol azeotrope before and after separation by 1-hexyl-3-methylimidazole acetate (HMIMOAc). The key findings are as follows: (1) the interaction between HMIMOAc and ethanol is significantly stronger than that between EP and ethanol. (2) The interaction between [OAc]- in HMIMOAc and ethanol plays a critical role in eliminating the azeotrope. (3) Ethanol self-aggregates, EP-ethanol interaction complexes, and HMIMOAc-ethanol interaction complexes were identified and characterized using excess spectroscopy and quantum chemical calculations.
Related Concept Videos
E1 Reaction: Stereochemistry and Regiochemistry
E2 Reaction: Stereochemistry and Regiochemistry
When a substrate with two different β hydrogens undergoes an E2 elimination, the presence of a strong base can yield two regioisomeric alkenes. The more-substituted alkene is the major...
Ethers from Alkenes: Alcohol Addition and Alkoxymercuration-Demercuration
Ethers can also be prepared from alkenes through acid-catalyzed addition of alcohols and alkoxymercuration–demercuration.
Preparation of Ethers by Acid-Catalyzed Addition of Alcohol to Alkenes
The acid-catalyzed addition of alcohol to an alkene involves treating the alkene with an excess of alcohol in the presence of an acid catalyst to form an ether under suitable conditions. The hydrogen will add to the less substituted carbon so that the nucleophile can attack the more...
Oxymercuration-Reduction of Alkenes
Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
E2 Reaction: Kinetics and Mechanism


