1
|
Zhang Y, Tan X, Ding W, Wang Y, He H, Yu Z. Tracking the Micro-Heterogeneity and Hydrogen-Bonding Interactions in Hydroxyl-Functionalized Ionic Liquid Solutions: A Combined Experimental and Computational Study. Chemphyschem 2021; 22:1891-1899. [PMID: 34236730 DOI: 10.1002/cphc.202100395] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 07/06/2021] [Indexed: 01/03/2023]
Abstract
Ionic liquids (ILs) are an important class of media that are usually used in combination with polar solvents to reduce costs and tune their physicochemical properties. In this regard, it is essential to understand the influence of adding solvents on the properties of ILs. In this work, the micro-heterogeneity and H-bonding interactions between a hydroxyl-functionalized IL, [HOEmim][TFSI], and acetonitrile (ACN) were investigated by attenuated total reflection Fourier transform infrared spectroscopy and molecular simulations. All studied IL-ACN mixtures were found to deviate from the ideal mixtures. The degree of deviations reaches the maximum at about x(ACN)=0.7 with the presence of both homogeneous clusters of pure IL/ACN and heterogeneous clusters of IL-ACN. With the addition of ACN to IL, the mixtures undergo the transformation from "ACN solvated in [HOEmim][TFSI]" to "[HOEmim][TFSI] solvated in ACN". It is found that the newly formed H-bonding interactions between the IL and ACN is the main factor that contributes to the red shifts of O-H, C2 -H, C4,5 -H, and Calkyl -H of [HOEmim]+ cation, and the blue shifts of C-D, C≡N of ACN, and C-F, S=O of [TFSI]- anion. These in-depth studies on the mixtures of hydroxyl-functionalized IL and acetonitrile would help to understand the micro-heterogeneity and H-bonding interactions of miscible solutions and shed light on exploring their applications.
Collapse
Affiliation(s)
- Yaqin Zhang
- Beijing Key Laboratory of Ionic Liquids Clean Process, Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, P. R. China.,Department of Materials Science & Engineering, City University of Hong Kong, Hong Kong, P. R. China
| | - Xin Tan
- Beijing Key Laboratory of Ionic Liquids Clean Process, Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Weilu Ding
- Beijing Key Laboratory of Ionic Liquids Clean Process, Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Yanlei Wang
- Beijing Key Laboratory of Ionic Liquids Clean Process, Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Hongyan He
- Beijing Key Laboratory of Ionic Liquids Clean Process, Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, P. R. China.,Innovation Academy for Green Manufacture, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Zhiwu Yu
- MOE Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| |
Collapse
|
2
|
Ma J, Wang Y, Yang X, Wang B. Fast Track to Acetate-Based Ionic Liquids: Preparation, Properties and Application in Energy and Petrochemical Fields. Top Curr Chem (Cham) 2021; 379:2. [PMID: 33398607 DOI: 10.1007/s41061-020-00315-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 11/16/2020] [Indexed: 11/25/2022]
Abstract
Acetate-based ionic liquids (AcILs), as a kind of typical carboxylate-based ILs, display excellent structure tunability, non-volatility, good solubility to biomass, and favorable adsorption capacity, etc. These unique characteristics of AcILs make them important candidates for a range of applications in the field of energy and in the petrochemical industry. This paper intends to provide a comprehensive overview of recent advances in AcILs, including pure AcILs, AcIL-based multi-solvents, and AcIL-based composites, etc. Preparation methods, with one- and two-step synthesis, are reviewed. The relationship between properties and temperature is discussed, and some physical and thermodynamic properties of different AcILs are summarized and further calculated. The applications of AcILs in the fields of biomass processing, organic synthesis, separation, electrochemistry, and other fields are reviewed based on their prominent properties. Thereinto, the dual functions of AcILs as solvents and activators for biomass dissolution are discussed, and the roles of AcILs as catalysts and reaction mediums in clean organic synthesis are highlighted. Meanwhile, the reaction mechanisms of AcILs with acid gases are posed by means of molecular simulation and experimental characterization. Moreover, AcILs as electrolytes for zinc batteries, supercapacitors, and electrodeposition are particularly introduced. Finally, the future research challenges and prospects of AcILs are presented.
Collapse
Affiliation(s)
- Jing Ma
- Key Laboratory for Green Chemical Technology of Ministry of Education, R&D Center for Petrochemical Technology, Tianjin University, Tianjin, 300072, China.,Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Yutong Wang
- Key Laboratory for Green Chemical Technology of Ministry of Education, R&D Center for Petrochemical Technology, Tianjin University, Tianjin, 300072, China.,Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Xueqing Yang
- Key Laboratory for Green Chemical Technology of Ministry of Education, R&D Center for Petrochemical Technology, Tianjin University, Tianjin, 300072, China.,Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Baohe Wang
- Key Laboratory for Green Chemical Technology of Ministry of Education, R&D Center for Petrochemical Technology, Tianjin University, Tianjin, 300072, China. .,Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072, China.
| |
Collapse
|
3
|
Kalhor P, Li QZ, Zheng YZ, Yu ZW. Is the Fourier Transform Infrared Free-OH Band of t-Butanol Only from Free OHs? Case Studies on the Binary Systems of the Alcohol with CCl 4 and CHCl 3. J Phys Chem A 2020; 124:6177-6185. [PMID: 32623889 DOI: 10.1021/acs.jpca.0c03463] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Attenuated total reflection-Fourier transform infrared spectroscopy and quantum chemical calculations were performed on tert-butyl alcohol (t-BuOH) and its binary solutions with CCl4 and CHCl3. The study was focused on the free-OH stretching bands. Two resolution-enhancing methods, excess spectroscopy and two-dimensional correlation spectroscopy, were employed to examine the structural heterogeneity and search for the detailed contributors to the free-OH bands. Unexpectedly, CCl4 was found not to be an inert solvent and, similar to CHCl3, formed hydrogen/halogen bonds (H-/X-bond) with t-BuOH. It was observed that the free-OH band in the t-BuOH-CHCl3 system is larger and more red-shifted than that in the t-BuOH-CCl4 system, indicating the stronger intermolecular interactions in the former system. Furthermore, in the t-BuOH-CHCl3 system, the H-bonds are stronger than the X-bonds, while in the t-BuOH-CCl4 system, both interactions are similar in strength. To assign the free-OH bands, it was found that they are not only from the free OH of the t-BuOH monomer, but they are also contributed by the quasi-free OH with the oxygen bonded to H or Cl and even the weakly H-bonded OH of t-BuOH molecules. Finally, all the identified species increased simultaneously via cosolvent addition, suggestive of the destabilization of the highly associated t-BuOH clusters.
Collapse
Affiliation(s)
- Payam Kalhor
- MOE Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Qing-Zhong Li
- The Laboratory of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Yantai University, Yantai 264005, China
| | - Yan-Zhen Zheng
- College of Animal Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zhi-Wu Yu
- MOE Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China
| |
Collapse
|
4
|
Zhang Y, Wu Z, Wang Y, He H, Yu Z. Excess spectroscopy and its applications in the study of solution chemistry. PURE APPL CHEM 2020. [DOI: 10.1515/pac-2020-0107] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Abstract
Characterization of structural heterogeneity of liquid solutions and the pursuit of its nature have been challenging tasks to solution chemists. In the last decade, an emerging method called excess spectroscopy has found applications in this area. The method, combining the merits of molecular spectroscopy and excess thermodynamic functions, shows the ability to enhance the apparent resolution of spectra, provides abundant information concerning solution structures and intermolecular interactions. In this review, the thinking and mathematics of the method, as well as its developments, are presented first. Then, research progress related to the exploration of the method is thoroughly reviewed. The materials are classified into two parts, small-molecular solutions and ionic liquid solutions. Finally, potential challenges and the perspective for further development of the method are discussed.
Collapse
Affiliation(s)
- Yaqin Zhang
- CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Beijing Key Laboratory of Ionic Liquids Clean Process , Institute of Process Engineering, Chinese Academy of Sciences , Beijing 100190 , P.R. China
| | - Zhiwei Wu
- CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Beijing Key Laboratory of Ionic Liquids Clean Process , Institute of Process Engineering, Chinese Academy of Sciences , Beijing 100190 , P.R. China
| | - Yaqian Wang
- MOE Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology, Department of Chemistry , Tsinghua University , Beijing 100084 , P.R. China
| | - Hongyan He
- CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Beijing Key Laboratory of Ionic Liquids Clean Process , Institute of Process Engineering, Chinese Academy of Sciences , Beijing 100190 , P.R. China
| | - Zhiwu Yu
- MOE Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology, Department of Chemistry , Tsinghua University , Beijing 100084 , P.R. China
| |
Collapse
|
5
|
Kalhor P, Xu J, Ashraf H, Cao B, Yu ZW. Structural Properties and Hydrogen-Bonding Interactions in Binary Mixtures Containing a Deep-Eutectic Solvent and Acetonitrile. J Phys Chem B 2020; 124:1229-1239. [PMID: 31984745 DOI: 10.1021/acs.jpcb.9b10751] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Deep-eutectic solvents (DESs) are a new class of green solvents. Here, we report the hydrogen bonding and structural properties of the archetypal DES ethaline, a mixture of choline chloride (ChCl) and ethylene glycol (EG) of a 1:2 molar ratio, and its pseudo-binary mixtures with acetonitrile. The investigations were carried out employing Fourier-transform infrared (FTIR) spectroscopy combined with quantum chemical calculations. Excess and two-dimensional (2D)-correlation spectroscopies were used to identify favorable species in the solutions and to explore the heterogeneity. The results show that the mixing process is the transformation from ethaline and CH3CN dimer to the complexes of ethaline-1CH3CN and ethaline-2CH3CN, together with the increased percentages of the EG dimer, EG trimer, and CH3CN monomer with respect to their total amounts in the mixtures. Theoretical calculations show that, for ChCl, the positive charge is located at the methyl groups and methylenes, rendering their ability to form hydrogen bonds. Adding CH3CN to ethaline can hardly break apart the doubly ionic hydrogen bonds between Ch+ and Cl-. The cosolvent molecules mainly surround the core structure of ethaline, forming noncovalent hydrogen bonds with hydroxyl groups of EG/Ch+ but not Cl-. These in-depth studies on the properties of ethaline and CH3CN/CD3CN mixed solvents may shed light on exploring their applications.
Collapse
Affiliation(s)
- Payam Kalhor
- MOE Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology, Department of Chemistry , Tsinghua University , Beijing 100084 , China
| | - Jing Xu
- MOE Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology, Department of Chemistry , Tsinghua University , Beijing 100084 , China
| | - Hamad Ashraf
- MOE Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology, Department of Chemistry , Tsinghua University , Beijing 100084 , China
| | - Bobo Cao
- MOE Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology, Department of Chemistry , Tsinghua University , Beijing 100084 , China
| | - Zhi-Wu Yu
- MOE Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology, Department of Chemistry , Tsinghua University , Beijing 100084 , China
| |
Collapse
|
6
|
Xu J, Deng G, Wang YT, Guo HY, Kalhor P, Yu ZW. Local Acid Strength of Solutions and Its Quantitative Evaluation Using Excess Infrared Nitrile Probes. J Phys Chem Lett 2020; 11:1007-1012. [PMID: 31958952 DOI: 10.1021/acs.jpclett.9b03804] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We propose the concept of local acidity in condensed-phase chemistry in this work. The feature is demonstrated in trifluoroethanol (TFE) by employing two Fourier-transform infrared spectroscopy (FTIR) nitrile probes, acetonitrile (CH3CN) and benzonitrile (PhCN). Specifically, three positive excess peaks were found in the binary systems composed of TFE and a probe using excess spectroscopy. To characterize the local acidity quantitatively, we have tried to correlate the wavenumbers of the positive excess peaks of the probes and the pKa values in water of a series of XH-containing compounds (X = O, N, and C). Good linear relationships were discovered. Accordingly, three different pKa values of TFE were determined based on the three positive excess infrared peaks, which are attributed to the monomer, dimer, and trimer of TFE with the help of quantum-chemical calculations. The concept of local acidity and its quantitative evaluation enrich our knowledge of acid-base chemistry and will shed light on a better understanding of microstructures of solutions.
Collapse
Affiliation(s)
- Jing Xu
- MOE Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology, Department of Chemistry , Tsinghua University , Beijing 100084 , P. R. China
| | - Geng Deng
- MOE Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology, Department of Chemistry , Tsinghua University , Beijing 100084 , P. R. China
| | - Yu-Tian Wang
- MOE Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology, Department of Chemistry , Tsinghua University , Beijing 100084 , P. R. China
| | - Hao-Yue Guo
- MOE Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology, Department of Chemistry , Tsinghua University , Beijing 100084 , P. R. China
| | - Payam Kalhor
- MOE Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology, Department of Chemistry , Tsinghua University , Beijing 100084 , P. R. China
| | - Zhi-Wu Yu
- MOE Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology, Department of Chemistry , Tsinghua University , Beijing 100084 , P. R. China
| |
Collapse
|