1
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Hsieh AY, Haines RS, Harper JB. Effects of Ionic Liquids on the Nucleofugality of Bromide. J Org Chem 2024; 89:6247-6256. [PMID: 38655582 DOI: 10.1021/acs.joc.4c00249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
The nucleofugality of bromide was measured in solvent mixtures containing ionic liquids. The solvolysis rate constants of the bromides of well-defined electrofuges were determined in mixtures containing different proportions of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide in ethanol. Temperature-dependent kinetic studies allowed an explanation of the observed solvent effects in different mixtures in terms of interactions in solution. Using the solvolysis data, the nucleofugality of bromide in these systems was determined. Likewise, nucleofugality data for bromide were determined in mixtures containing high proportions of seven further ionic liquids. These data allowed quantification of the effects of both varying the amount of ionic liquid and the nature of ionic liquid components on the nucleofugality of bromide. Importantly, ionic liquid mixtures were shown to affect the nucleofugality in a manner similar to chloride, providing a method for predicting the effects of ionic liquids on other electrofuges. Further, the ionic liquids were shown to move the transition state earlier along the reaction coordinate, meaning that there is less charge development in the transition state.
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Affiliation(s)
- Andrew Y Hsieh
- School of Chemistry, University of New South Wales, UNSW, Sydney, NSW 2052, Australia
| | - Ronald S Haines
- School of Chemistry, University of New South Wales, UNSW, Sydney, NSW 2052, Australia
| | - Jason B Harper
- School of Chemistry, University of New South Wales, UNSW, Sydney, NSW 2052, Australia
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2
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Hsieh AY, Haines RS, Harper JB. The effects of ionic liquids on the ethanolysis of a chloroacenaphthene. Evaluation of the effectiveness of nucleofugality data to predict reaction outcome. RSC Adv 2023; 13:21036-21043. [PMID: 37448642 PMCID: PMC10336772 DOI: 10.1039/d3ra04302a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 06/30/2023] [Indexed: 07/15/2023] Open
Abstract
The reaction of a chlorobenzene in mixtures containing ethanol and eight different ionic liquids was investigated in order to understand the effects of varying proportions and constituent ions of an ionic liquid on the rate constant of the process. The results were found to be generally consistent with previously studied reactions of the same type, with small proportions of an ionic liquid resulting in a rate constant increase compared to ethanol and large proportions causing a rate constant decrease. Temperature dependent kinetic studies were used to interpret the changes in reaction outcome, particularly noting an entropic cost on moving to high proportions of ionic liquid, consistent with organisation of solvent around the transition state. While attempts to use empirical solvent parameters to correlate outcome with the ionic liquid used were unsuccessful, use of recently acquired nucleofugality data for chloride and estimations for the electrofuge allowed for excellent prediction of the effects of ionic liquids, with rate constants quantitatively predicted in systems containing both different proportions of ionic liquid (mean absolute error (MAE) log(k1) = 0.11) and different ionic liquids (MAE log(k1) = 0.33). Importantly, this demonstrates the ready application of these quantitative reactivity parameters.
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Affiliation(s)
- Andrew Y Hsieh
- School of Chemistry, University of New South Wales UNSW Sydney NSW 2052 Australia +61 2 9385 6141 +61 2 9385 4692
| | - Ronald S Haines
- School of Chemistry, University of New South Wales UNSW Sydney NSW 2052 Australia +61 2 9385 6141 +61 2 9385 4692
| | - Jason B Harper
- School of Chemistry, University of New South Wales UNSW Sydney NSW 2052 Australia +61 2 9385 6141 +61 2 9385 4692
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3
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1,3-Bis(3-Carboxypropyl)-1H-Imidazole. MOLBANK 2022. [DOI: 10.3390/m1480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The use of γ-aminobutyric acid (GABA) as a starting material in a multicomponent reaction has resulted in the preparation of the zwitterionic 1,3-bis(3-carboxypropyl)imidazole (bcpim). The synthesis of this imidazole derivative in a one-pot procedure with stoichiometric amounts of the corresponding reagents (formaldehyde, glyoxal, and GABA in a 1:1:2 ratio) has resulted in a straightforward and effective methodology, meaning a significant improvement from a sustainable point of view.
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4
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Vong A, Schwartz BJ. Bond-Breaking Reactions Encounter Distinct Solvent Environments Causing Breakdown of Linear Response. J Phys Chem Lett 2022; 13:6783-6791. [PMID: 35856802 DOI: 10.1021/acs.jpclett.2c01656] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Solvent effects are important for understanding solution-phase chemical reactions. Surprisingly, very few studies have explored how solvent dynamics change during the course of a reaction with solutes that encounter a wide range of configurations. Here, we use quantum simulation methods to explore the solvent dynamics during a solution-phase bond-breaking reaction: the photodissociation of Na2+ in liquid Ar. We find that the solute experiences a small number of distinct solvent environments that change in a discrete fashion as the bond lengthens. In characterizing the solvent environments, we show also that linear response fails by all measures, even when nonstationarity of solvent dynamics is considered. This observation of distinct solvent response environments with a solvent that can undergo only translational motions highlights the complexity of solute-solvent interactions, but that there are only a few environments gives hope to the idea that solvation dynamics can be understood for solution-phase reactions that explore a wide configuration space.
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Affiliation(s)
- Andy Vong
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, United States
| | - Benjamin J Schwartz
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, United States
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5
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Coney MD, Morris DC, Gilbert A, Prescott SW, Haines RS, Harper JB. Effects of Ionic Liquids on the Nucleofugality of Chloride. J Org Chem 2021; 87:1767-1779. [PMID: 34756050 DOI: 10.1021/acs.joc.1c02043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The nucleofugality of chloride has been measured in solvent mixtures containing ionic liquids for the first time, allowing reactivity in these solvents to be put in context with molecular solvents. Using well-described electrofuges, solvolysis rate constants were determined in mixtures containing different proportions of ethanol and the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide; the different solvent effects observed as the mixture changed could be explained using interactions of the ionic liquid with species along the reaction coordinate, determined using temperature dependent kinetic studies. The solvolysis data allowed determination of the nucleofugality of chloride in these mixtures, which varied with the proportion of salt in the reaction mixture, demonstrating quantitatively the importance of the amount of ionic liquid in the reaction mixture in determining reaction outcome. Nucleofugality data for chloride were determined in seven further ionic liquids, with the reactivity shown to vary over more than an order of magnitude. This outcome illustrates that the components of the ionic liquid are critical in determining reaction outcome. Overall, this work quantitatively extends the understanding of solvent effects in ionic liquids and demonstrates the potential for such information to be used to rationally select an ionic liquid to control reaction outcome.
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6
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Gilbert A, Haines RS, Harper JB. The effects of using an ionic liquid as a solvent for a reaction that proceeds through a phenonium ion. J PHYS ORG CHEM 2021. [DOI: 10.1002/poc.4217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Alyssa Gilbert
- School of Chemistry University of New South Wales, UNSW Sydney Sydney New South Wales Australia
| | - Ronald S. Haines
- School of Chemistry University of New South Wales, UNSW Sydney Sydney New South Wales Australia
| | - Jason B. Harper
- School of Chemistry University of New South Wales, UNSW Sydney Sydney New South Wales Australia
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7
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Greaves TL, Schaffarczyk McHale KS, Burkart-Radke RF, Harper JB, Le TC. Machine learning approaches to understand and predict rate constants for organic processes in mixtures containing ionic liquids. Phys Chem Chem Phys 2021; 23:2742-2752. [PMID: 33496292 DOI: 10.1039/d0cp04227g] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The ability to tailor the constituent ions in ionic liquids (ILs) is highly advantageous as it provides access to solvents with a range of physicochemical properties. However, this benefit also leads to large compositional spaces that need to be explored to optimise systems, often involving time consuming experimental work. The use of machine learning methods is an effective way to gain insight based on existing data, to develop structure-property relationships and to allow the prediction of ionic liquid properties. Here we have applied machine learning models to experimentally determined rate constants of a representative organic process (the reaction of pyridine with benzyl bromide) in IL-acetonitrile mixtures. Multiple linear regression (MLREM) and artificial neural networks (BRANNLP) were both able to model the data well. The MLREM model was able to identify the structural features on the cations and anions that had the greatest effect on the rate constant. Secondly, predictive MLREM and BRANNLP models were developed from the full initial set of rate constant data. From these models, a large number of predictions (>9000) of rate constant were made for mixtures of different ionic liquids, at different proportions of ionic liquid and molecular solvent, at different temperatures. A selection of these predictions were tested experimentally, including through the preparation of novel ionic liquids, with overall good agreement between the predicted and experimental data. This study highlights the benefits of using machine learning methods on kinetic data in ionic liquid mixtures to enable the development of rigorous structure-property relationships across multiple variables simultaneously, and to predict properties of new ILs and experimental conditions.
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Affiliation(s)
- Tamar L Greaves
- College of Science Engineering and Health, RMIT University, Melbourne, VIC 3001, Australia.
| | | | | | - Jason B Harper
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia.
| | - Tu C Le
- College of Science Engineering and Health, RMIT University, Melbourne, VIC 3001, Australia.
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8
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Kochly ED, Deh-Lee AM, Lemon NJ, Rath J, Escobar-Meza A. The effect of ionic liquid cosolvents on a unimolecular solvolysis reaction in 2,2,2-trifluoroethanol. RESULTS IN CHEMISTRY 2021. [DOI: 10.1016/j.rechem.2021.100213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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9
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Knoevenagel condensation versus Michael addition reaction in ionic-liquid-catalyzed synthesis of hexahydroquinoline: a SMD–DFT study. Theor Chem Acc 2020. [DOI: 10.1007/s00214-020-2565-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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10
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Schaffarczyk McHale KS, Haines RS, Harper JB. Ionic Liquids as Solvents for S N 2 Processes. Demonstration of the Complex Interplay of Interactions Resulting in the Observed Solvent Effects. Chempluschem 2020; 83:1162-1168. [PMID: 31950706 DOI: 10.1002/cplu.201800510] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 11/03/2018] [Indexed: 11/11/2022]
Abstract
Bimolecular nucleophilic substitution reactions between triphenylphosphine and benzylic electrophiles have been examined in an ionic liquid to probe interactions with species along the reaction coordinate. Trends in the rate constant were found on both varying the leaving group and the electronic nature of the aromatic ring. In all the cases considered, interactions between the components of the ionic liquid and the transition state were shown to be more significant in determining reaction outcome than previously observed for this class of reaction. This demonstrates the importance of considering interactions of the ionic liquid components with all species along the reaction coordinate when investigating the origin of ionic liquid solvent effects, along with how such effects might be exploited.
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Affiliation(s)
| | - Ronald S Haines
- School of Chemistry, University of New South Wales UNSW, Sydney, NSW 2052, Australia
| | - Jason B Harper
- School of Chemistry, University of New South Wales UNSW, Sydney, NSW 2052, Australia
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11
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Schaffarczyk McHale KS, Haines RS, Harper JB. Investigating Variation of the Pnicogen Nucleophilic Heteroatom on Ionic Liquid Solvent Effects in Bimolecular Nucleophilic Substitution Processes. Chempluschem 2020; 84:534-539. [PMID: 31943899 DOI: 10.1002/cplu.201900188] [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: 03/26/2019] [Revised: 05/03/2019] [Indexed: 01/22/2023]
Abstract
A series of nucleophiles containing Group 15 nucleophilic heteroatoms has been used to expand and develop the current understanding of ionic liquid solvent effects on bimolecular nucleophilic substitution processes. It was found that when using arsenic-, antimony- and bismuth-based nucleophiles, rate constant enhancement was observed for all solvent compositions containing ionic liquids. This rate constant enhancement was driven by ionic liquid/transition state interactions, which contrasts with previous studies on earlier Group 15 nucleophiles. This study provides a holistic understanding and augments the predictive framework for the effects of ionic liquids on bimolecular nucleophilic substitution processes, with the potential for these periodic trends to be broadly applied.
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Affiliation(s)
| | - Ronald S Haines
- School of Chemistry, University of New South Wales, UNSW Sydney, NSW 2052, Australia
| | - Jason B Harper
- School of Chemistry, University of New South Wales, UNSW Sydney, NSW 2052, Australia
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12
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Gilbert A, Haines RS, Harper JB. Controlling the reactions of 1-bromogalactose acetate in methanol using ionic liquids as co-solvents. Org Biomol Chem 2020; 18:5442-5452. [PMID: 32638805 DOI: 10.1039/d0ob01198c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reactions of an acetobromogalactose in mixtures of methanol and one of seven different ionic liquids with varying constituent ions were studied. In general, small amounts of ionic liquid in the reaction mixture led to increases in the rate constant compared to methanol, whilst large amounts of ionic liquid led to decreases in the rate constant; this outcome differs significantly from previous reactions proceeding through this mechansim. Temperature dependent kinetic studies indicated that the dominant interaction driving these changes was between the ionic liquid and the transition state of the process. Through considering solvent parameters of ionic liquids, a relationship was found between the changes in the rate constant and both the hydrogen bond accepting ability and polarisability of the solvent, indicating that the interactions affecting reaction outcome are both specific and non-specific in nature; once more, these interactions were different to those observed in previous similar reactions. By changing the amount of ionic liquid in the reaction mixture, additional products not seen in the molecular solvent case were observed, the ratios of which are dependent on the anion of the ionic liquid and the proportion of ionic liquid in the reaction mixture. This demonstrates the importance of considering solvent effects on both the rate and product determining steps and the potential application of such changes is discussed.
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Affiliation(s)
- Alyssa Gilbert
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia.
| | - Ronald S Haines
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia.
| | - Jason B Harper
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia.
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13
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Gilbert A, Bucher G, Haines RS, Harper JB. Correlating ionic liquid solvent effects with solvent parameters for a reaction that proceeds through a xanthylium intermediate. Org Biomol Chem 2019; 17:9336-9342. [PMID: 31612896 DOI: 10.1039/c9ob01807g] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A unimolecular nucleophilic substitution reaction that proceeds through a xanthylium carbocation was studied in seven ionic liquid solvents. It was found that the general trend in the rate constant with changing proportion of ionic liquid in the reaction mixture was different to that seen for other unimolecular processes, with the rate constant increasing as more ionic liquid was added to the reaction mixture. A significant correlation was found between the natural logarithm of the rate constant and a combination of the Kamlet-Taft solvent parameters. This relationship indicated that the principal interaction involved hydrogen bonding between the ionic liquid and some species along the reaction coordinate. Further, this correlation enables prediction of the effects that other ionic liquids will have on this, and other, reactions that proceed through a similar intermediate.
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Affiliation(s)
- Alyssa Gilbert
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia.
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14
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Schindl A, Hagen ML, Muzammal S, Gunasekera HAD, Croft AK. Proteins in Ionic Liquids: Reactions, Applications, and Futures. Front Chem 2019; 7:347. [PMID: 31179267 PMCID: PMC6543490 DOI: 10.3389/fchem.2019.00347] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 04/26/2019] [Indexed: 01/01/2023] Open
Abstract
Biopolymer processing and handling is greatly facilitated by the use of ionic liquids, given the increased solubility, and in some cases, structural stability imparted to these molecules. Focussing on proteins, we highlight here not just the key drivers behind protein-ionic liquid interactions that facilitate these functionalities, but address relevant current and potential applications of protein-ionic liquid interactions, including areas of future interest.
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Affiliation(s)
- Alexandra Schindl
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, United Kingdom
- Faculty of Medicine & Health Sciences, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
- Faculty of Science, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom
| | - Matthew L. Hagen
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, United Kingdom
- Centre for Additive Manufacturing, Faculty of Engineering, University of Nottingham, Nottingham, United Kingdom
| | - Shafaq Muzammal
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, United Kingdom
| | - Henadira A. D. Gunasekera
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, United Kingdom
- Centre for Additive Manufacturing, Faculty of Engineering, University of Nottingham, Nottingham, United Kingdom
| | - Anna K. Croft
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, United Kingdom
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15
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Kostić M, Verdía P, Fernández‐Stefanuto V, Puchta R, Tojo E. A mild and efficient procedure for alkenols oxyselenocyclization by using ionic liquids. J PHYS ORG CHEM 2019. [DOI: 10.1002/poc.3928] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Marina Kostić
- Faculty of Science, Department of ChemistryUniversity of Kragujevac Kragujevac Serbia
| | - Pedro Verdía
- Department of Organic ChemistryUniversidade de Vigo, Marcosende Vigo Spain
| | | | - Ralph Puchta
- Inorganic Chemistry, Department of Chemistry and PharmacyUniversity of Erlangen‐Nürnberg Erlangen Germany
- Computer Chemistry Center, Department of Chemistry and PharmacyUniversity of Erlangen‐Nuremberg Erlangen Germany
- Central Instituite for Scientific Computing (ZISC)Friedrich‐Alexander University Erlangen‐Nürnberg Martensstrasse 5a Erlangen Germany
| | - Emilia Tojo
- Department of Organic ChemistryUniversidade de Vigo, Marcosende Vigo Spain
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16
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Gilbert A, Haines RS, Harper JB. Understanding the effects of ionic liquids on a unimolecular substitution process: correlating solvent parameters with reaction outcome. Org Biomol Chem 2019; 17:675-682. [DOI: 10.1039/c8ob02460j] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The polarisability of an ionic liquid is key in determining the rate constant of a unimolecular substitution process.
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Affiliation(s)
- Alyssa Gilbert
- School of Chemistry
- University of New South Wales
- Sydney
- Australia
| | | | - Jason B. Harper
- School of Chemistry
- University of New South Wales
- Sydney
- Australia
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17
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Keaveney ST, Harper JB, Croft AK. Ion-Reagent Interactions Contributing to Ionic Liquid Solvent Effects on a Condensation Reaction. Chemphyschem 2018; 19:3279-3287. [PMID: 30289579 DOI: 10.1002/cphc.201800695] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Indexed: 11/09/2022]
Abstract
Molecular dynamics simulations of solutions of hexan-1-amine or 4-methoxybenzaldehyde in acetonitrile, an ionic liquid/acetonitrile mixture (χIL =0.2), and a number of different (neat) ionic liquids were performed, to further understand the solvent effects on the condensation reaction of these species. This work indicates that, in the presence of an ionic liquid, the amine group of hexan-1-amine is exclusively solvated by the components of the ionic liquid, and not by acetonitrile, and that the anion interacts with the aldehyde group of 4-methoxybenzaldehyde. These interactions showed little dependence on the proportion of the ionic liquid present. When varying the cation of the ionic liquid there were changes in the cation-amine interaction, and 1-butyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide ([Bm2 im][N(CF3 SO2 )2 ]) was found to order more than expected about the amine. This ordering is likely the origin of the large rate constant values determined in [Bm2 im][N(CF3 SO2 )2 ] for this condensation reaction and explains an anomaly seen previously. When changing the anion, changes were seen in the interactions between both the cation and anion with hexan-1-amine, and the anion with 4-methoxybenzaldehyde. The differing magnitude of these interactions likely causes subtle changes in the activation parameters for this condensation reaction, and provides an explanation for the anomalous rate constant values previously determined when varying the anion.
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Affiliation(s)
- Sinead T Keaveney
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia
- Department of Molecular Sciences, Macquarie University, North Ryde, NSW 2109, Australia
| | - Jason B Harper
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia
| | - Anna K Croft
- Department of Chemical and Environmental Engineering, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
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18
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Hawker RR, Haines RS, Harper JB. Predicting solvent effects in ionic liquids:
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xtension of a nucleophilic aromatic substitution reaction on a benzene to a pyridine. J PHYS ORG CHEM 2018. [DOI: 10.1002/poc.3862] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Rebecca R. Hawker
- School of Chemistry University of New South Wales UNSW Sydney Australia
| | - Ronald S. Haines
- School of Chemistry University of New South Wales UNSW Sydney Australia
| | - Jason B. Harper
- School of Chemistry University of New South Wales UNSW Sydney Australia
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19
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Butler BJ, Harper JB. The effect of the structure of the anion of an ionic liquid on the rate of reaction at a phosphorus centre. J PHYS ORG CHEM 2018. [DOI: 10.1002/poc.3819] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Bradley J. Butler
- School of Chemistry; University of New South Wales, UNSW; Sydney Australia
| | - Jason B. Harper
- School of Chemistry; University of New South Wales, UNSW; Sydney Australia
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20
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Hawker RR, Haines RS, Harper JB. The effect of varying the anion of an ionic liquid on the solvent effects on a nucleophilic aromatic substitution reaction. Org Biomol Chem 2018; 16:3453-3463. [DOI: 10.1039/c8ob00651b] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Variety of ionic liquids with different anions used as solvents for a nucleophilic aromatic substitution reaction.
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Affiliation(s)
| | | | - Jason B. Harper
- School of Chemistry
- University of New South Wales
- Sydney
- Australia
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21
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22
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Keaveney ST, Haines RS, Harper JB. Ionic liquid solvents: the importance of microscopic interactions in predicting organic reaction outcomes. PURE APPL CHEM 2017. [DOI: 10.1515/pac-2016-1008] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractIonic liquids are attractive alternatives to molecular solvents as they have many favourable physical properties and can produce different organic reaction outcomes compared to molecular solvents. Thus far, interactions between the ionic liquid components and specific sites (such as charged centres, lone pairs and π systems) on the reagents and transition state have been identified as affecting reaction outcome; a comprehensive understanding of these interactions is necessary to allow prediction of ionic liquid solvent effects. This manuscript summarises our recent progress in the development of a framework for predicting the effect of an ionic liquid solvent on the outcome of organic processes. There will be a particular focus on the importance of the different interactions between the ionic liquid components and the species along the reaction coordinate that are responsible for the changes in reaction outcome observed in the cases described.
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Affiliation(s)
- Sinead T. Keaveney
- School of Chemistry, University of New South Wales, UNSW Sydney 2052, Australia
| | - Ronald S. Haines
- School of Chemistry, University of New South Wales, UNSW Sydney 2052, Australia
| | - Jason B. Harper
- School of Chemistry, University of New South Wales, UNSW Sydney 2052, Australia
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23
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Keaveney ST, Haines RS, Harper JB. Investigating Solvent Effects of an Ionic Liquid on Pericyclic Reactions through Kinetic Analyses of Simple Rearrangements. Chempluschem 2017; 82:449-457. [DOI: 10.1002/cplu.201600585] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 01/02/2017] [Indexed: 11/12/2022]
Affiliation(s)
- Sinead T. Keaveney
- School of Chemistry University of New South Wales Sydney NSW 2052 Australia
| | - Ronald S. Haines
- School of Chemistry University of New South Wales Sydney NSW 2052 Australia
| | - Jason B. Harper
- School of Chemistry University of New South Wales Sydney NSW 2052 Australia
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24
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Hawker RR, Wong MJ, Haines RS, Harper JB. Rationalising the effects of ionic liquids on a nucleophilic aromatic substitution reaction. Org Biomol Chem 2017; 15:6433-6440. [DOI: 10.1039/c7ob01476g] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The nucleophilic aromatic substitution reaction between 1-fluoro-2,4-dinitrobenzene and ethanol was examined in a series of ionic liquids across a range of mole fractions.
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Affiliation(s)
| | | | | | - Jason B. Harper
- School of Chemistry
- University of New South Wales
- Sydney
- Australia
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Keaveney ST, Greaves TL, Kennedy DF, Harper JB. Understanding the Effect of Solvent Structure on Organic Reaction Outcomes When Using Ionic Liquid/Acetonitrile Mixtures. J Phys Chem B 2016; 120:12687-12699. [PMID: 27973829 DOI: 10.1021/acs.jpcb.6b11090] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The rate constant for the reaction between hexan-1-amine and 4-methoxybenzaldehyde was determined in ionic liquids containing an imidazolium cation. The effect on the rate constant of increasing the length of the alkyl substituent on the cation was examined in a number of ionic liquid/acetonitrile mixtures. In general it was found that there was no significant effect of changing the alkyl substituent on the rate constant of this process, suggesting that any nanodomains in these mixtures do not have a significant effect on the outcome of this process. A series of small-angle X-ray scattering and wide-angle X-ray scattering experiments were performed on mixtures of the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([Bmim][N(CF3SO2)2]) and acetonitrile; this work indicated that the main structural changes in the mixtures occur by about a 0.2 mole fraction of ionic liquid in the mixture (χIL). This region at which the main changes in the solvent structuring occurs corresponds to the region at which the main changes in the rate constant and activation parameters occur for SN2 and condensation reactions examined previously; this is the first time that such a correlation has been observed. To examine the ordering of the solvent about the nucleophile hexan-1-amine, WAXS experiments were performed on a number of [Bmim][N(CF3SO2)2]/acetonitrile/hexan-1-amine mixtures, where it was found that some of the patterns featured asymmetric peaks as well as additional peaks not observed in the [Bmim][N(CF3SO2)2]/acetonitrile mixtures; this suggests that the addition of hexan-1-amine to the mixture affects the bulk structure of the liquid. The SAXS/WAXS patterns of mixtures of 1-butyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide ([Bm2im][N(CF3SO2)2]) and acetonitrile were also determined, with the results suggesting that [Bm2im][N(CF3SO2)2] is more ordered than [Bmim][N(CF3SO2)2] due to an enhancement in the short-range interactions.
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Affiliation(s)
- Sinead T Keaveney
- School of Chemistry, University of New South Wales , Sydney, NSW 2052, Australia
| | - Tamar L Greaves
- School of Science, College of Science, Engineering and Health, RMIT University , Melbourne, VIC 3001, Australia
| | | | - Jason B Harper
- School of Chemistry, University of New South Wales , Sydney, NSW 2052, Australia
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Keaveney ST, Schaffarczyk McHale KS, Stranger JW, Ganbold B, Price WS, Harper JB. NMR Diffusion Measurements as a Simple Method to Examine Solvent-Solvent and Solvent-Solute Interactions in Mixtures of the Ionic Liquid [Bmim][N(SO2CF3)2] and Acetonitrile. Chemphyschem 2016; 17:3853-3862. [DOI: 10.1002/cphc.201600927] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Sinead T. Keaveney
- School of Chemistry; University of New South Wales, UNSW; Sydney NSW 2052 Australia
| | | | - James W. Stranger
- Nanoscale Organisation and Dynamics Group; Western Sydney University; Locked Bag 1797, Penrith NSW 2751 Australia
| | - Batchimeg Ganbold
- Nanoscale Organisation and Dynamics Group; Western Sydney University; Locked Bag 1797, Penrith NSW 2751 Australia
| | - William S. Price
- Nanoscale Organisation and Dynamics Group; Western Sydney University; Locked Bag 1797, Penrith NSW 2751 Australia
| | - Jason B. Harper
- School of Chemistry; University of New South Wales, UNSW; Sydney NSW 2052 Australia
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Hawker RR, Panchompoo J, Aldous L, Harper JB. Novel Chloroimidazolium‐Based Ionic Liquids: Synthesis, Characterisation and Behaviour as Solvents to Control Reaction Outcome. Chempluschem 2016; 81:574-583. [DOI: 10.1002/cplu.201600099] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 04/06/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Rebecca R. Hawker
- School of Chemistry University of New South Wales Sydney NSW 2052 Australia
| | - Janjira Panchompoo
- School of Chemistry University of New South Wales Sydney NSW 2052 Australia
| | - Leigh Aldous
- School of Chemistry University of New South Wales Sydney NSW 2052 Australia
| | - Jason B. Harper
- School of Chemistry University of New South Wales Sydney NSW 2052 Australia
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Schaffarczyk McHale KS, Hawker RR, Harper JB. Nitrogen versus phosphorus nucleophiles – how changing the nucleophilic heteroatom affects ionic liquid solvent effects in bimolecular nucleophilic substitution processes. NEW J CHEM 2016. [DOI: 10.1039/c6nj00721j] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Changing the nucleophile gave different ionic liquid effects, showing the importance of interactions with all species along the reaction coordinate.
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Affiliation(s)
| | | | - Jason B. Harper
- School of Chemistry
- University of New South Wales
- Sydney
- Australia
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