Hydrogen bond promoted thermal stability enhancement of acetate based ionic liquid

Ling Zhang; Ligang Wei; Shangru Zhai; Dingwei Zhao; Jian Sun; Qingda An

doi:10.1016/j.cjche.2020.02.019

Hydrogen bond promoted thermal stability enhancement of acetate based ionic liquid

Ling Zhang, Ligang Wei, Shangru Zhai, Dingwei Zhao, Jian Sun^*, Qingda An

^*Corresponding author for this work

School of Life Science

Research output: Contribution to journal › Article › peer-review

17 Citations (Scopus)

Abstract

Acetate-based imidazolium ionic liquids (ILs) are of great importance and widely applied in biomass processing and engineering but under stability issue due to the structure self–rearrangement induced by C₂–H deprotonation, by which the IL based biomass processing will be challenging. Herein, we demonstrated that the thermal stability of normal acetate-based imidazolim [C₈C₁Im][OAc] could be significantly improved by changing its cation and anion environment with the presence of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide IL ([C₄C₁Im][NTf₂]). When the molar fraction of [C₈C₁Im][OAc] was 0.3, the thermal stability of [C₈C₁Im][OAc] could be significantly improved (ΔT_5%dec = + 43 °C). Detailed information obtained from thermal gravimetric analysis (TGA) and nuclear magnetic resonance (NMR) revealed that the addition of [C₄C₁Im][NTf₂] played a significant role in enhancing the thermal stability of [C₈C₁Im][OAc]. It was proposed that the formation of an anion–π⁺ structure network between [C₈C₁Im][OAc] and [C₄C₁Im][NTf₂] via strong hydrogen bond interactions greatly affects the environment of hydrogen atom in the imidazolium ring of each IL.

Original language	English
Pages (from-to)	1293-1301
Number of pages	9
Journal	Chinese Journal of Chemical Engineering
Volume	28
Issue number	5
DOIs	https://doi.org/10.1016/j.cjche.2020.02.019
Publication status	Published - May 2020

Keywords

Binary ionic liquids
Hydrogen bond interactions
Imidazolium salt
Thermal stability

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@article{b13556c420184145bfe9958b019d8ec2,

title = "Hydrogen bond promoted thermal stability enhancement of acetate based ionic liquid",

abstract = "Acetate-based imidazolium ionic liquids (ILs) are of great importance and widely applied in biomass processing and engineering but under stability issue due to the structure self–rearrangement induced by C2–H deprotonation, by which the IL based biomass processing will be challenging. Herein, we demonstrated that the thermal stability of normal acetate-based imidazolim [C8C1Im][OAc] could be significantly improved by changing its cation and anion environment with the presence of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide IL ([C4C1Im][NTf2]). When the molar fraction of [C8C1Im][OAc] was 0.3, the thermal stability of [C8C1Im][OAc] could be significantly improved (ΔT5\%dec = + 43 °C). Detailed information obtained from thermal gravimetric analysis (TGA) and nuclear magnetic resonance (NMR) revealed that the addition of [C4C1Im][NTf2] played a significant role in enhancing the thermal stability of [C8C1Im][OAc]. It was proposed that the formation of an anion–π+ structure network between [C8C1Im][OAc] and [C4C1Im][NTf2] via strong hydrogen bond interactions greatly affects the environment of hydrogen atom in the imidazolium ring of each IL.",

keywords = "Binary ionic liquids, Hydrogen bond interactions, Imidazolium salt, Thermal stability",

author = "Ling Zhang and Ligang Wei and Shangru Zhai and Dingwei Zhao and Jian Sun and Qingda An",

note = "Publisher Copyright: {\textcopyright} 2020 Elsevier B.V.",

year = "2020",

month = may,

doi = "10.1016/j.cjche.2020.02.019",

language = "English",

volume = "28",

pages = "1293--1301",

journal = "Chinese Journal of Chemical Engineering",

issn = "1004-9541",

publisher = "Materials China",

number = "5",

}

TY - JOUR

T1 - Hydrogen bond promoted thermal stability enhancement of acetate based ionic liquid

AU - Zhang, Ling

AU - Wei, Ligang

AU - Zhai, Shangru

AU - Zhao, Dingwei

AU - Sun, Jian

AU - An, Qingda

PY - 2020/5

Y1 - 2020/5

N2 - Acetate-based imidazolium ionic liquids (ILs) are of great importance and widely applied in biomass processing and engineering but under stability issue due to the structure self–rearrangement induced by C2–H deprotonation, by which the IL based biomass processing will be challenging. Herein, we demonstrated that the thermal stability of normal acetate-based imidazolim [C8C1Im][OAc] could be significantly improved by changing its cation and anion environment with the presence of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide IL ([C4C1Im][NTf2]). When the molar fraction of [C8C1Im][OAc] was 0.3, the thermal stability of [C8C1Im][OAc] could be significantly improved (ΔT5%dec = + 43 °C). Detailed information obtained from thermal gravimetric analysis (TGA) and nuclear magnetic resonance (NMR) revealed that the addition of [C4C1Im][NTf2] played a significant role in enhancing the thermal stability of [C8C1Im][OAc]. It was proposed that the formation of an anion–π+ structure network between [C8C1Im][OAc] and [C4C1Im][NTf2] via strong hydrogen bond interactions greatly affects the environment of hydrogen atom in the imidazolium ring of each IL.

AB - Acetate-based imidazolium ionic liquids (ILs) are of great importance and widely applied in biomass processing and engineering but under stability issue due to the structure self–rearrangement induced by C2–H deprotonation, by which the IL based biomass processing will be challenging. Herein, we demonstrated that the thermal stability of normal acetate-based imidazolim [C8C1Im][OAc] could be significantly improved by changing its cation and anion environment with the presence of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide IL ([C4C1Im][NTf2]). When the molar fraction of [C8C1Im][OAc] was 0.3, the thermal stability of [C8C1Im][OAc] could be significantly improved (ΔT5%dec = + 43 °C). Detailed information obtained from thermal gravimetric analysis (TGA) and nuclear magnetic resonance (NMR) revealed that the addition of [C4C1Im][NTf2] played a significant role in enhancing the thermal stability of [C8C1Im][OAc]. It was proposed that the formation of an anion–π+ structure network between [C8C1Im][OAc] and [C4C1Im][NTf2] via strong hydrogen bond interactions greatly affects the environment of hydrogen atom in the imidazolium ring of each IL.

KW - Binary ionic liquids

KW - Hydrogen bond interactions

KW - Imidazolium salt

KW - Thermal stability

UR - https://www.scopus.com/pages/publications/85083014556

U2 - 10.1016/j.cjche.2020.02.019

DO - 10.1016/j.cjche.2020.02.019

M3 - Article

AN - SCOPUS:85083014556

SN - 1004-9541

VL - 28

SP - 1293

EP - 1301

JO - Chinese Journal of Chemical Engineering

JF - Chinese Journal of Chemical Engineering

IS - 5

ER -

Hydrogen bond promoted thermal stability enhancement of acetate based ionic liquid

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