1
|
Karton A, Foller T, Joshi R. Catalyzing epoxy oxygen migration on the basal surface of graphene oxide using strong hydrogen-bond donors. Chem Commun (Camb) 2024; 60:7049-7052. [PMID: 38895846 DOI: 10.1039/d4cc01911c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
High-level double-hybrid DFT simulations reveal that strong hydrogen-bond-donor catalysts (e.g., ethylene glycol, guanidine, and thiourea) significantly accelerate the migration of epoxy oxygen on the surface of graphene oxide, enhancing the reaction rate by 6-12 orders of magnitude. These results shed light on previously puzzling experimental observations.
Collapse
Affiliation(s)
- Amir Karton
- School of Science and Technology, University of New England, Armidale, NSW 2351, Australia.
| | - Tobias Foller
- School of Materials Science and Engineering, University of New South Wales Sydney, NSW, 2052, Australia
| | - Rakesh Joshi
- School of Materials Science and Engineering, University of New South Wales Sydney, NSW, 2052, Australia
| |
Collapse
|
2
|
Smith GJ, Koutsoukos S, Lancaster B, Becker J, Welton T, Hunt PA. Unravelling ionic liquid solvent effects for a non-polar Cope rearrangement reaction. Phys Chem Chem Phys 2024; 26:12453-12466. [PMID: 38625536 DOI: 10.1039/d4cp00156g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
The impact of ionic liquids (ILs) on polar reactions is well recognised, however the impact of ILs on non-polar reactions is less well understood or explored. Pericyclic Cope rearrangements are highly concerted, exhibit minimal charge localisation and pass through an uncharged but well-defined transition state, and thus provide a good mechanism for exploring the impact of IL polarizability on chemical reactivity. Recently, a 10× rate enhancement has been observed for the Cope rearrangement of 3-phenyl-1,5-hexadiene in the IL 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [C4C1im][NTf2] compared to benzene. In this work we undertake a DFT based computational study (B3LYP-D3BJ/6-311+G(d,p) and M06-2X-D3/6-311+G(d,p)) of the Cope rearrangement of 3-phenyl-1,5-hexadiene and 3-propyl-hexa-1,5-diene in molecular solvents (acetonitrile, benzene and ethanol) and the IL [C4C1im][NTf2] using the SMD solvation model. The impact of benzene and [C4C1im][NTf2] on the Cope rearrangement of 3-phenyl-1,5-hexadiene is studied in more detail and we provide insight into the reason for the rate enhancement in an IL. The volume of activation is evaluated and the potential impact of 'solvent pressure' is discussed. We identify two potential mechanisms for volume effects to contribute to the rate enhancement. Solvent association energies are evaluated at the DLNPO-CCSD(T) level. Specific solvent interactions are explored through atomic partial charge, molecular orbital and bond critical point analysis, as well as via non-colvalent interaction (NCI) plots, electrostatic potential (ESP) differences and density difference Δρ(r) plots. We find that the cation and anion together form an extensive van der Waals pocket in-which the transition state (TS) sits. Electron density within the TS is anisotropically polarised via a 'push-pull' effect due to the dual cation-anion nature of the IL, stabilising the TS relative to benzene. We also provide experimental evidence that these effects are generalisable to other ILs. Overall, our aim is to provide a deeper moleuclar level understanding of the impact of ILs on non-polar reactions.
Collapse
Affiliation(s)
- Gavin J Smith
- Department of Chemistry, Imperial College London, UK
| | | | - Ben Lancaster
- Department of Chemistry, Imperial College London, UK
| | - Julian Becker
- Department of Chemistry, Imperial College London, UK
| | - Tom Welton
- Department of Chemistry, Imperial College London, UK
| | - Patricia A Hunt
- Department of Chemistry, Imperial College London, UK
- School of Chemical and Physical Sciences, Victoria University of Wellington, New Zealand.
| |
Collapse
|
3
|
Dohmen C, Paululat T, Ihmels H. Reversible Restrain and Release of the Dynamic Valence Isomerization in a Shape-shifting Bullvalene by Complex Formation. Chemistry 2024; 30:e202304311. [PMID: 38275100 DOI: 10.1002/chem.202304311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Revised: 01/25/2024] [Accepted: 01/26/2024] [Indexed: 01/27/2024]
Abstract
In search for structural features that enable the control of the valence isomerization of the fluxional bullvalene, a bullvalene-bis(harmane) conjugate is identified that acts as chelating ligand in complexes with metal ions. Spectrometric titrations show that this ligand forms 1 : 1 complexes with Ag+, Cu+, Cu2+, and Zn2+. Most importantly, detailed NMR-spectroscopic analysis at different temperatures reveals that the complexation with Ag+ strongly affects the dynamic isomerization of the bullvalene unit of the ligand such that only one predominant valence isomer is formed, even at 5 °C. Detailed 1H-NMR-spectroscopic studies disclose an increased barrier (~11 kJ mol-1) of the Cope rearrangement. Furthermore, the addition of hexacyclene displaces the Ag+ from the complex, so that the valence isomerization is accelerated and an equilibrium with two predominant isomers is formed. In turn, repeated addition of Ag+ regains the complex with the restrained isomerization of the bullvalene unit. This method to control the valence isomerism by straightforward chemical stimuli may be used to simplify structural analysis at elevated temperatures, i. e. a feature not available so far with bullvalenes, and it may be employed as functional element in dynamic supramolecular assemblies.
Collapse
Affiliation(s)
- Christoph Dohmen
- Department of Chemistry-Biology, and Center of Micro-and Nanochemistry and (Bio)Technology (Cμ), University of Siegen, Adolf-Reichwein-Str. 2, 57068, Siegen, Germany
| | - Thomas Paululat
- Department of Chemistry-Biology, and Center of Micro-and Nanochemistry and (Bio)Technology (Cμ), University of Siegen, Adolf-Reichwein-Str. 2, 57068, Siegen, Germany
| | - Heiko Ihmels
- Department of Chemistry-Biology, and Center of Micro-and Nanochemistry and (Bio)Technology (Cμ), University of Siegen, Adolf-Reichwein-Str. 2, 57068, Siegen, Germany
| |
Collapse
|
4
|
Li H, Mansoori Kermani M, Ottochian A, Crescenzi O, Janesko BG, Truhlar DG, Scalmani G, Frisch MJ, Ciofini I, Adamo C. Modeling Multi-Step Organic Reactions: Can Density Functional Theory Deliver Misleading Chemistry? J Am Chem Soc 2024; 146:6721-6732. [PMID: 38413362 DOI: 10.1021/jacs.3c12713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
Many organic reactions are characterized by a complex mechanism with a variety of transition states and intermediates of different chemical natures. Their correct and accurate theoretical characterization critically depends on the accuracy of the computational method used. In this work, we study a complex ambimodal cycloaddition with five transition states, two intermediates, and three products, and we ask whether density functional theory (DFT) can provide a correct description of this type of complex and multifaceted reaction. Our work fills a gap in that most systematic benchmarks of DFT for chemical reactions have considered much simpler reactions. Our results show that many density functionals not only lead to seriously large errors but also differ from one another in predicting whether the reaction is ambimodal. Only a few of the available functionals provide a balanced description of the complex and multifaceted reactions. The parameters varied in the tested functionals are the ingredients, the treatment of medium-range and nonlocal correlation energy, and the inclusion of Hartree-Fock exchange. These results show a clear need for more benchmarks on the mechanisms of large molecules in complex reactions.
Collapse
Affiliation(s)
- Hanwei Li
- Chimie ParisTech, PSL Research University, CNRS, Institute of Chemistry for Life and Health Sciences, Paris F-75005, France
| | - Maryam Mansoori Kermani
- Department of Chemistry, Chemical Theory Center, and Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
| | - Alistar Ottochian
- Chimie ParisTech, PSL Research University, CNRS, Institute of Chemistry for Life and Health Sciences, Paris F-75005, France
| | - Orlando Crescenzi
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario di Monte Sant'Angelo, Via Cinthia, Napoli 80126, Italy
| | - Benjamin G Janesko
- Department of Chemistry & Biochemistry, Texas Christian University, Fort Worth, Texas 76129, United States
| | - Donald G Truhlar
- Department of Chemistry, Chemical Theory Center, and Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
| | | | | | - Ilaria Ciofini
- Chimie ParisTech, PSL Research University, CNRS, Institute of Chemistry for Life and Health Sciences, Paris F-75005, France
| | - Carlo Adamo
- Chimie ParisTech, PSL Research University, CNRS, Institute of Chemistry for Life and Health Sciences, Paris F-75005, France
- Institut Universitaire de France, 103 Boulevard Saint Michel, Paris F-75005, France
| |
Collapse
|
5
|
Baroudi A, Jaradat K, Karton A. 6-Endo-dig versus 5-exo-dig: Exploring Radical Cyclization Preference with First-, Second-, and Third-row Linkers using High-level Quantum Chemical Methods. Chemphyschem 2023; 24:e202300426. [PMID: 37392178 DOI: 10.1002/cphc.202300426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 06/25/2023] [Accepted: 06/26/2023] [Indexed: 07/03/2023]
Abstract
As an expansion upon Baldwin rules, the cyclization reactions of hex-5-yn-1-yl radical systems with different first-, second-, and third-row linkers are explored at the CCSD(T) level via means of the SMD(benzene)-G4(MP2) thermochemical protocol. Unlike C, O, and N linkers, systems with B, Si, P, S, Ge, As, and Se linkers are shown to favor 6-endo-dig cyclization. This offers fundamental insights into the rational synthetic design of cyclic compounds. A thorough analysis of stereoelectronic effects, cyclization barriers, and intrinsic barriers illustrates that structural changes alter the cyclization preference by mainly impacting 5-exo-dig reaction barriers. Based on the high-level computational modeling, we proceed to develop a new tool for cyclization preference prediction from the correlation between cyclization barriers and radical structural parameters (e. g., linker bond length and bond angle). A strong correlation is found between the radical attack trajectory angle and the reaction barrier heights, i. e., cyclization preference. Finally, the influence of stereoelectronic effects on the two radical cyclization pathways is further investigated in stereoisomers of hypervalent silicon system, which provides novel insight into cyclization control.
Collapse
Affiliation(s)
- Abdulkader Baroudi
- College of Engineering and Technology, American University of the Middle East, Kuwait
| | - Khaled Jaradat
- College of Engineering and Technology, American University of the Middle East, Kuwait
| | - Amir Karton
- School of Science and Technology, University of New England, Armidale, NSW 2351, Australia
| |
Collapse
|
6
|
Karton A, Greatrex BW, O'Reilly RJ. Intramolecular Proton-Coupled Hydride Transfers with Relatively Low Activation Barriers. J Phys Chem A 2023. [PMID: 37368352 DOI: 10.1021/acs.jpca.3c03166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
We report that bifunctional molecules containing hydroxyl and carbonyl functional groups can undergo an effective transfer hydrogenation via an intramolecular proton-coupled hydride transfer (PCHT) mechanism. In this reaction mechanism, a hydride transfer between two carbon atoms is coupled with a proton transfer between two oxygen atoms via a cyclic bond rearrangement transition structure. The coupled transfer of the two hydrogens as Hδ+ and Hδ- is supported by atomic polar tensor charges. The activation energy for the PCHT reaction is strongly dependent on the length of the alkyl chain between the hydroxyl and carbonyl functional groups but relatively weakly dependent on the functional groups attached to the hydroxyl and carbonyl carbons. We investigate the PCHT reaction mechanism using the Gaussian-4 thermochemical protocol and obtain high activation energy barriers (ΔH‡298) of 210.5-228.3 kJ mol-1 for chain lengths of one carbon atom and 160.2-163.9 kJ mol-1 for chain lengths of two carbon atoms. However, for longer chain lengths containing 3-4 carbon atoms, we obtain ΔH‡298 values as low as 101.9 kJ mol-1. Importantly, the hydride transfer between two carbon atoms proceeds without the need for a catalyst or hydride transfer activating agent. These results indicate that the intramolecular PCHT reaction provides an effective avenue for uncatalyzed, metal-free hydride transfers at ambient temperatures.
Collapse
Affiliation(s)
- Amir Karton
- School of Science and Technology, University of New England, Armidale, NSW 2351, Australia
| | - Ben W Greatrex
- School of Rural Medicine, University of New England, Armidale, NSW 2351, Australia
| | - Robert J O'Reilly
- School of Science and Technology, University of New England, Armidale, NSW 2351, Australia
| |
Collapse
|
7
|
Laconsay CJ, Tantillo DJ. Modulating Escape Channels of Cycloheptatrienyl Rhodium Carbenes To Form Semibullvalene. J Org Chem 2023. [PMID: 37335974 DOI: 10.1021/acs.joc.3c00735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2023]
Abstract
We describe the various escape channels available to dirhodium carbene intermediates from cycloheptatrienyl diazo compounds located with density functional theory. An intramolecular cyclopropanation would, in principle, provide a new route to semibullvalenes (SBVs). A detailed exploration of the potential energy surface reveals that methylating carbon-7 suppresses a competing β-hydride migration pathway to heptafulvene products, giving SBV formation a reasonable chance. During our explorations, we additionally discovered unusual spirononatriene, spironorcaradiene, and metal-stabilized 9-barbaralyl cation structures as local minima.
Collapse
Affiliation(s)
- Croix J Laconsay
- Department of Chemistry, University of California─Davis, Davis, California 95616, United States
| | - Dean J Tantillo
- Department of Chemistry, University of California─Davis, Davis, California 95616, United States
| |
Collapse
|
8
|
Bismillah AN, Johnson TG, Hussein BA, Turley AT, Saha PK, Wong HC, Aguilar JA, Yufit DS, McGonigal PR. Control of dynamic sp 3-C stereochemistry. Nat Chem 2023; 15:615-624. [PMID: 36914791 PMCID: PMC10159849 DOI: 10.1038/s41557-023-01156-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 02/09/2023] [Indexed: 03/16/2023]
Abstract
Stereogenic sp3-hybridized carbon centres are fundamental building blocks of chiral molecules. Unlike dynamic stereogenic motifs, such as sp3-nitrogen centres or atropisomeric biaryls, sp3-carbon centres are usually fixed, requiring intermolecular reactions to undergo configurational changes. Here we report the internal enantiomerization of fluxional carbon cages and the consequences of their adaptive configurations for the transmission of stereochemical information. The sp3-carbon stereochemistry of the rigid tricyclic cages is inverted through strain-assisted Cope rearrangements, emulating the low-barrier configurational dynamics typical for sp3-nitrogen inversion or conformational isomerism. This dynamic enantiomerization can be stopped, restarted or slowed by external reagents, while the configuration of the cage is controlled by neighbouring, fixed stereogenic centres. As part of a phosphoramidite-olefin ligand, the fluxional cage acts as a conduit to transmit stereochemical information from the ligand while also transferring its dynamic properties to chiral-at-metal coordination environments, influencing catalysis, ion pairing and ligand exchange energetics.
Collapse
Affiliation(s)
| | | | | | | | | | - Ho Chi Wong
- Department of Chemistry, Durham University, Durham, UK
| | | | | | - Paul R McGonigal
- Department of Chemistry, Durham University, Durham, UK. .,Department of Chemistry, University of York, York, UK.
| |
Collapse
|
9
|
Shapeshifting radicals. Chem Phys 2022. [DOI: 10.1016/j.chemphys.2021.111373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
10
|
Kozuch S, Karton A, Jalife S, Merino G. Fluxionality by quantum tunnelling: nonclassical 21-homododecahedryl cation rearrangement re-revisited. Chem Commun (Camb) 2021; 57:10735-10738. [PMID: 34585183 DOI: 10.1039/d1cc04036g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The 21-homododecahedryl cation is a unique system in terms of its complete fluxionality based on two different rearrangements. In this work, we report the quantum tunneling effects that drive the reactions at temperatures where the semi-classical kinetics are impossible. We postulate that the tunnel effect in this system can serve to create a refrigerator that may operate at arbitrarily low temperatures.
Collapse
Affiliation(s)
- Sebastian Kozuch
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva 841051, Israel.
| | - Amir Karton
- School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia
| | - Said Jalife
- Departamento de Física Aplicada, Centro de Investigación y de Estudios Avanzados, 97310, Mérida, Yucatán, Mexico.
| | - Gabriel Merino
- Departamento de Física Aplicada, Centro de Investigación y de Estudios Avanzados, 97310, Mérida, Yucatán, Mexico.
| |
Collapse
|
11
|
Li H, Brémond E, Sancho-García JC, Adamo C. Pairing double hybrid functionals with a tailored basis set for an accurate thermochemistry of hydrocarbons. RSC Adv 2021; 11:26073-26082. [PMID: 35479441 PMCID: PMC9037073 DOI: 10.1039/d1ra04108h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 07/19/2021] [Indexed: 11/21/2022] Open
Abstract
A collection of five challenging datasets, including noncovalent interactions, reaction barriers and electronic rearrangements of medium-sized hydrocarbons, has been selected to verify the robustness of double-hybrid functionals used in conjunction with the small DH-SVPD basis set, especially developed for noncovalent interactions. The analysis is completed by other, more standard functionals, for a total of 17 models, including also empirical corrections for dispersion. The obtained results show that the chemical accuracy threshold, that is an error lower than 1.0 kcal mol−1, can be obtained by pairing the nonempirical PBE-QIDH functional with the DH-SVPD basis set, as well as by other semi-empirical functionals, such as DSD-PBEP86, using larger basis sets and empirical corrections. More in general, a significant improvement can be obtained using the DH-SVPD basis set with DHs, without resorting to any empirical corrections. This choice leads to a fast computational protocol that, avoiding any empirical potential, remains on a fully quantum ground. The pairing of the PBE-QIDH double-hybrid functional with a tailored split-valence basis set leads to a fast computational protocol for the accurate evaluation of hydrocarbon thermochemistry, without resorting to any empirical correction.![]()
Collapse
Affiliation(s)
- Hanwei Li
- Chimie ParisTech, PSL Research University, CNRS, Institute of Chemistry for Health and Life Sciences F-75005 Paris France
| | - Eric Brémond
- Université de Paris, ITODYS, CNRS F-75006 Paris France
| | | | - Carlo Adamo
- Chimie ParisTech, PSL Research University, CNRS, Institute of Chemistry for Health and Life Sciences F-75005 Paris France .,Institut Universitaire de France 103 Boulevard Saint Michel F-75005 Paris France
| |
Collapse
|
12
|
Li H, Tirri B, Brémond E, Sancho-García JC, Adamo C. Beyond Chemical Accuracy for Alkane Thermochemistry: The DH thermo Approach. J Org Chem 2021; 86:5538-5545. [PMID: 33822605 DOI: 10.1021/acs.joc.1c00058] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The so-called protobranching phenomenon, that is the greater stability of branched alkanes with respect to their linear isomers, represents an interesting challenge for approaches based on density functional theory (DFT), since it requires a balanced description of several electronic effects, including (intramolecular) dispersion forces. Here, we investigate this problem using a protocol recently developed based on double-hybrid functionals and a small basis set, DH-SVPD, suited for noncovalent interactions. The energies of bond separation reactions (BSR), defined on the basis of an isodesmic principle, are taken as reference properties for the evaluation of 15 DFT approaches. The obtained results show that error lower than the so-called "chemical accuracy" (<1.0 kcal/mol) can be obtained by the proposed protocol on both relative reaction energies and enthalpies. These results are then verified on the standard BSR36 data set and support the proposition of our computational protocol, named DHthermo, where any DH functional, such as PBE-QIDH or B2PLYP, provides accurate results when coupled to an empirical dispersion correction and the DH-SVPD basis set. This protocol not only gives subchemical accuracy on the thermochemistry of alkanes but it is extremely easy to use with common quantum-chemistry codes.
Collapse
Affiliation(s)
- Hanwei Li
- Chimie ParisTech, PSL Research University, CNRS, Institute of Chemistry for Health and Life Sciences, F-75005 Paris, France
| | - Bernardino Tirri
- Chimie ParisTech, PSL Research University, CNRS, Institute of Chemistry for Health and Life Sciences, F-75005 Paris, France
| | - Eric Brémond
- Université de Paris, ITODYS, CNRS, F-75006 Paris, France
| | | | - Carlo Adamo
- Chimie ParisTech, PSL Research University, CNRS, Institute of Chemistry for Health and Life Sciences, F-75005 Paris, France.,Institut Universitaire de France, 103 Boulevard Saint Michel, F-75005 Paris, France
| |
Collapse
|