1
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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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2
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Morris DC, Prescott SW, Harper JB. Rapid relaxation NMR measurements to predict rate coefficients in ionic liquid mixtures. An examination of reaction outcome changes in a homologous series of ionic liquids. Phys Chem Chem Phys 2021; 23:9878-9888. [PMID: 33908419 DOI: 10.1039/d0cp06066f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of ionic liquids based on the 1-alkyl-3-methylimidazolium cations were examined as components of the solvent mixture for a bimolecular substitution process. The effects on both the rate coefficient of the process and the NMR spin-spin relaxation of the solvent components of changing either the alkyl chain length or the amount of ionic liquid in the reaction mixture were determined. At a constant mole fraction, a shorter alkyl chain length resulted in a greater rate coefficient enhancement and a longer relaxation time, with the opposite effects for a longer alkyl chain length. For a given ionic liquid, increasing the proportion of salt in the reaction mixture resulted in a greater rate coefficient and a shorter relaxation time. The microscopic origins of the rate coefficient enhancement were determined and a step change found in the activation parameters on increasing the alkyl chain length from hexyl to octyl, suggesting notable structuring in solution. Across a range of ionic liquids and solvent compositions, the relaxation time from NMR measurements was shown to relate to the reaction rate coefficient. The approach of using fast and simple NMR relaxation measurements to predict reaction outcomes was exemplified using a morpholinium-based ionic liquid.
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Affiliation(s)
- Daniel C Morris
- School of Chemical Engineering, University of New South Wales, Sydney, NSW 2052, Australia.
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3
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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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4
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Chardin C, Durand A, Jarsalé K, Rouden J, Livi S, Baudoux J. Sulfonimides versus ketosulfonamides as epoxidized imidazolium counterions: towards a new generation of ionic liquid monomers. NEW J CHEM 2021. [DOI: 10.1039/d0nj05126h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ionic liquid monomers with various sulfonimides or ketosulfonamides as unprecedented counteranions of imidazolium ILs were submitted to the Prilezhaev reaction and the intrinsic properties of these new epoxy monomers was unveiled.
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Affiliation(s)
- C. Chardin
- Laboratoire de Chimie Moléculaire et Thio-organique
- ENSICAEN
- Université de Caen Normandie
- CNRS
- 6 boulevard du Maréchal Juin
| | - A. Durand
- Laboratoire de Chimie Moléculaire et Thio-organique
- ENSICAEN
- Université de Caen Normandie
- CNRS
- 6 boulevard du Maréchal Juin
| | - K. Jarsalé
- Laboratoire de Chimie Moléculaire et Thio-organique
- ENSICAEN
- Université de Caen Normandie
- CNRS
- 6 boulevard du Maréchal Juin
| | - J. Rouden
- Laboratoire de Chimie Moléculaire et Thio-organique
- ENSICAEN
- Université de Caen Normandie
- CNRS
- 6 boulevard du Maréchal Juin
| | - S. Livi
- Université de Lyon
- INSA Lyon
- UMR CNRS 5223
- IMP Ingénierie des Matériaux Polymères
- Villeurbanne F-69621
| | - J. Baudoux
- Laboratoire de Chimie Moléculaire et Thio-organique
- ENSICAEN
- Université de Caen Normandie
- CNRS
- 6 boulevard du Maréchal Juin
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5
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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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6
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Shashni S, Singh V, Toor AP. High-efficacy glycerol acetalization with silica gel immobilized Brønsted acid ionic liquid catalysts—preparation and comprehending the counter-anion effect on the catalytic activity. NEW J CHEM 2021. [DOI: 10.1039/d1nj03508h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Imidazolium sulfonate zwitterions (ZIs) with unconventional counter-anions were used to fabricate a series of mesoporous silica-gel-immobilized Brønsted acid ionic liquid (SG@BAIL) nanocatalysts.
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Affiliation(s)
- Shalini Shashni
- Energy Research Centre, Panjab University, Chandigarh, India
| | - Vasundhara Singh
- Department of Applied Science, PEC University of Technology, Chandigarh, India
| | - Amrit Pal Toor
- Energy Research Centre, Panjab University, Chandigarh, India
- Dr.SSBUICET, Panjab University, Chandigarh, India
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7
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Millán D, Rojas M, Tapia RA, Pavez P. Microwave-assisted nucleophilic degradation of organophosphorus pesticides in propylene carbonate. Org Biomol Chem 2020; 18:7868-7875. [PMID: 32985641 DOI: 10.1039/d0ob01620a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Propylene carbonate is becoming a suitable green alternative to volatile organic solvents in the study of chemical reactions. In this study, an efficient method for nucleophilic degradation of five organophosphorus pesticides, fenitrothion, malathion, diazinon, parathion, and paraoxon, using propylene carbonate as a solvent is proposed. The effect of changing the nature of the nucleophile and the influence of microwave (MW) heating were investigated. A screening of temperatures (50 °C-120 °C) was performed under microwave heating. The pesticide degradation was followed by 31P NMR, and the extent of conversion (%) was calculated by the integration of phosphorus signals. Keeping in mind that recently it has been reported that some ionic liquids play a nucleophilic role, in this work we report for the first time the degradation of organophosphorus pesticides by using an amino acid-based ionic liquid such as Bmim[Ala] as a nucleophile and a bio-based solvent (propylene carbonate) as a reaction medium in combination with microwave heating.
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Affiliation(s)
- Daniela Millán
- Centro Integrativo de Biología y Química Aplicada (CIBQA), Universidad Bernardo O'Higgins, General Gana 1702, Santiago, Chile.
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8
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Liu KTC, Haines RS, Harper JB. The effect of bisimidazolium-based ionic liquids on a bimolecular substitution process. Are two head(group)s better than one? Org Biomol Chem 2020; 18:7388-7395. [PMID: 32930294 DOI: 10.1039/d0ob01500h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A homologous series of biscationic ionic liquids based on two imidazolium centres, separated by alkyl chains of varying length, were examined as solvents for a bimolecular substitution reaction across a range of proportions of ionic liquid in the reaction mixture. Their effects on the rate constant of the process were compared to monocationic ionic liquids, with generally a greater rate constant increase observed. Importantly, it was observed that the magnitude of the effect was shown to vary with the length of the linking chain. To investigate the origins of these solvent effects, temperature dependent kinetic studies were performed to obtain activation parameters at high and low mole fractions of ionic liquid. The observed activation parameters showed the rate constant enhancement was due to interaction of the ionic liquid with the starting materials, consistent with previous results. Significantly, however, these data also showed that the balance of enthalpic and entropic effects varied dramatically with the length of the alkyl chain between the cationic centres.
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Affiliation(s)
- Kenny T-C Liu
- 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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9
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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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10
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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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11
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Schindl A, Hawker RR, Schaffarczyk McHale KS, Liu KTC, Morris DC, Hsieh AY, Gilbert A, Prescott SW, Haines RS, Croft AK, Harper JB, Jäger CM. Controlling the outcome of S N2 reactions in ionic liquids: from rational data set design to predictive linear regression models. Phys Chem Chem Phys 2020; 22:23009-23018. [PMID: 33043942 DOI: 10.1039/d0cp04224b] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Rate constants for a bimolecular nucleophilic substitution (SN2) process in a range of ionic liquids are correlated with calculated parameters associated with the charge localisation on the cation of the ionic liquid (including the molecular electrostatic potential). Simple linear regression models proved effective, though the interdependency of the descriptors needs to be taken into account when considering generality. A series of ionic liquids were then prepared and evaluated as solvents for the same process; this data set was rationally chosen to incorporate homologous series (to evaluate systematic variation) and functionalities not available in the original data set. These new data were used to evaluate and refine the original models, which were expanded to include simple artificial neural networks. Along with showing the importance of an appropriate data set and the perils of overfitting, the work demonstrates that such models can be used to reliably predict ionic liquid solvent effects on an organic process, within the limits of the data set.
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Affiliation(s)
- Alexandra Schindl
- Department of Chemical and Environmental Engineering, University of Nottingham, Nottingham NG7 2RD, UK.
| | - Rebecca R Hawker
- School of Chemistry, University of New South Wales, UNSW Sydney, 2052, Australia.
| | | | - Kenny T-C Liu
- School of Chemistry, University of New South Wales, UNSW Sydney, 2052, Australia.
| | - Daniel C Morris
- School of Chemistry, University of New South Wales, UNSW Sydney, 2052, Australia. and School of Chemical Engineering, University of New South Wales, UNSW Sydney, 2052, Australia
| | - Andrew Y Hsieh
- School of Chemistry, University of New South Wales, UNSW Sydney, 2052, Australia.
| | - Alyssa Gilbert
- School of Chemistry, University of New South Wales, UNSW Sydney, 2052, Australia.
| | - Stuart W Prescott
- School of Chemical Engineering, University of New South Wales, UNSW Sydney, 2052, Australia
| | - Ronald S Haines
- School of Chemistry, University of New South Wales, UNSW Sydney, 2052, Australia.
| | - Anna K Croft
- Department of Chemical and Environmental Engineering, University of Nottingham, Nottingham NG7 2RD, UK.
| | - Jason B Harper
- School of Chemistry, University of New South Wales, UNSW Sydney, 2052, Australia.
| | - Christof M Jäger
- Department of Chemical and Environmental Engineering, University of Nottingham, Nottingham NG7 2RD, UK.
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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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Schaffarczyk McHale KS, Wong MJ, Evans AK, Gilbert A, Haines RS, Harper JB. Understanding the effects of solvate ionic liquids as solvents on substitution processes. Org Biomol Chem 2019; 17:9243-9250. [PMID: 31599321 DOI: 10.1039/c9ob01753d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The effects of solvate ionic liquids as solvents have been considered for two substitution processes where the solvent effects of typical ionic liquids have been extensively investigated previously; the bimolecular nucleophilic substitution (SN2) reaction between pyridine and benzyl bromide and the nucleophilic aromatic substitution (SNAr) reaction between ethanol and 1-fluoro-2,4-dinitrobenzene. It was found that use of solvate ionic liquids gave rise to similar trends in the activation parameters for both substitution processes as typical ionic liquids, implying the microscopic interactions responsible for the effects were the same. However, different effects on the rate constants compared to typical ionic liquids were observed due to the changes in the balance of enthalpic and entropic contributions to the observed rate constants. From these data it is clear that the reaction outcome for both of these substitution reactions fall within the 'predictive framework' established in previous studies with a cautionary tale or two of their own to add to the general knowledge of ionic liquid solvent effects for these processes, particularly with respect to potential reactivity of the solvate ionic liquids themselves.
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14
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Vlasov VM. Influence of the activation entropy on the change of the isokinetic temperature in the SN2 reactions in solution. MONATSHEFTE FUR CHEMIE 2018. [DOI: 10.1007/s00706-018-2321-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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15
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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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16
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Hawker RR, Haines RS, Harper JB. Predicting solvent effects in ionic liquids:
E
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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17
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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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18
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Hawker RR, Haines RS, Harper JB. Rational selection of the cation of an ionic liquid to control the reaction outcome of a substitution reaction. Chem Commun (Camb) 2018; 54:2296-2299. [DOI: 10.1039/c8cc00241j] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Rational selection of ionic liquids to get the rate constant you want in a substitution process.
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Affiliation(s)
| | | | - Jason B. Harper
- School of Chemistry
- University of New South Wales
- Sydney
- Australia
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19
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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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20
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21
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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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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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23
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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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24
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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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25
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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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