Multiscale Exploration and Experimental Insights into Separating Neutral Heterocyclic Nitrogen Compounds Using [emim][NO₃] as an Extractant

Abstract

As valuable chemical materials, the heterocyclic nitrogen compounds are widely found in nature, and they are in common use. In this paper, the multiscale interaction mechanisms between 1-ethyl-3-methylimidazolium nitrate ([emim][NO ]) and representative heterocyclic nitrogen compounds (pyrrole and indole) during the extraction process are investigated. By combining theoretical and experimental research, first, the ionic liquid and its corresponding composite systems are studied with a multiscale microscopic method. With the help of quantum chemical calculation and molecular dynamics simulation, the polarity and the difference of the interactions of [emim][NO 3 ] and nitrogen compounds as well as the mechanism of the separation process are explored. Additionally, the mechanism of the separation process and its effects are evaluated through phase equilibrium measurement and extraction experiment. The results reveal the highly selective separation of neutral pyrrole and indole and lay a solid foundation for the development of a new extraction process for complex systems containing neutral heterocyclic nitrogen compounds.

Ternary (Liquid + Liquid) Equilibrium Experiment and Thermodynamic Modeling for Solvents (p-Xylene, Mesityl Oxide) + 2-Butanone + Water at 298.2, 303.2, and 313.2 K under 101.3 kPa

“…The data of the ternary system of solvents ( p -xylene, mesityl oxide) + 2-butanone + water is shown in Tables and , and the ternary diagrams are shown in Figures – . The D and S are the essential parameters to reflect the performance of the extractant. − The formulas are as follows , where w 2 I and w 2 II mean mass fractions of 2-butanone in organic (I) and aqueous (II), respectively. w 3 I and w 3 II mean mass fractions of water in organic (I) and aqueous (II), respectively.…”

Extraction performance evaluation and theoretical analysis of removal of phenol from oil mixture using a dual‐functionalized ionic liquid: 1‐hydroxyethyl‐3‐methylimidazolium propionate

“…The apparatus and procedure used in the study have been reported in the literature. 19,26,27 The prepared model oil and [EtOHmim][Pro] were mixed and stirred in a self-designed equilibrium cell under various extraction conditions. After equilibrium was achieved, a clear phase interface appeared.…”

Intermolecular Interaction and Extraction Explorations for Separation of High-Boiling Neutral Nitrogen Compounds Using Biodegradable Ionic Liquids

“…To explore the extraction interaction between indole with TMG-based ILs and carbazole with TMG-based ILs, in this work, MD simulations were performed using the GROMACS package at a temperature of 298.15 K . The LINCS algorithm was used for the Parrinello–Rahman barostat and the V-rescale thermostat in 1 atm. , The generalized amber force field (GAFF) was applied to the current separation system. ,− In particular, Multiwfn 3.8 was used to calculate the restrained electrostatic potential (RESP) to obtain the charge information of the small molecules (see Tables S6 and S7 for the partial charge of four ILs and representative oil). ,, The initial simulation systems prepared using PACKMOL in a cubic box (see Table S8 for the number of each compound) contained ILs, toluene, n -heptane, carbazole, and indole. The detailed setting information of the parameters is provided in Part B in the Supporting Information.…”

“…The detailed extraction apparatus and procedures can be referred to the previous work. ,, For analysis, the sample was withdrawn from the supernatant using a syringe. The content of carbazole and indole was analyzed using a Scion-456C gas chromatograph (see Table S9 for the detailed analysis conditions).…”