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Rajapakse RMG, Horrocks BR, Malikaramage AU, Gunarathna HMNP, Egodawele MGSAMEWDDK, Jayasinghe JMS, Ranatunga U, Herath WHMRNK, Sandakelum L, Wylie S, Abewardana PGPR, Seneviratne VN, Perera LLK, Velauthapillai D. Berberine isolation from Coscinium fenestratum: optical, electrochemical, and computational studies. RSC Adv 2023; 13:17062-17073. [PMID: 37293467 PMCID: PMC10245225 DOI: 10.1039/d3ra01769a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 05/22/2023] [Indexed: 06/10/2023] Open
Abstract
Berberine was extracted from Coscinium fenestratum (tree turmeric) and purified by column chromatography. The UV-Vis absorption spectroscopy of berberine was studied in acetonitrile and aqueous media. TD-DFT calculations employing the B3LYP functional were found to reproduce the general features of the absorption and emission spectra correctly. The electronic transitions to the first and second excited singlet states involve a transfer of electron density from the electron donating methylenedioxy phenyl ring to the electron accepting isoquinolium moiety. An estimate of the electrochemical gap (2.64 V) was obtained from microelectrode voltammetry and good agreement was found with quantum chemical calculations using the cc-pVTZ basis set and the B3LYP, CAM-B3LYP and wB97XD functionals. The calculations indicate spin density of the radical dication is delocalised over the molecule. These basic data are useful for assessment of the synthesis of donor-acceptor polymeric materials employing oxidative polymerization or co-polymerisation of berberine.
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Affiliation(s)
- R M Gamini Rajapakse
- Department of Chemistry, Faculty of Science, University of Peradeniya Peradeniya 20400 Sri Lanka
| | - Benjamin R Horrocks
- School of Natural and Environmental Sciences, Newcastle University Newcastle Upon Tyne NE1 4LB UK
| | - A U Malikaramage
- Department of Chemistry, Faculty of Science, University of Peradeniya Peradeniya 20400 Sri Lanka
| | - H M N P Gunarathna
- Department of Chemistry, Faculty of Science, University of Peradeniya Peradeniya 20400 Sri Lanka
| | | | - J M Susanthi Jayasinghe
- Department of Chemistry, Faculty of Science, University of Peradeniya Peradeniya 20400 Sri Lanka
| | - Udayana Ranatunga
- Department of Chemistry, Faculty of Science, University of Peradeniya Peradeniya 20400 Sri Lanka
| | - W H M R N K Herath
- Department of Chemistry, Faculty of Science, University of Peradeniya Peradeniya 20400 Sri Lanka
| | - Lahiru Sandakelum
- Department of Chemistry, Faculty of Science, University of Peradeniya Peradeniya 20400 Sri Lanka
| | - Shane Wylie
- Department of Chemistry, Faculty of Science, University of Peradeniya Peradeniya 20400 Sri Lanka
| | - P G P R Abewardana
- Department of Chemistry, Faculty of Science, University of Peradeniya Peradeniya 20400 Sri Lanka
| | - V N Seneviratne
- Department of Chemistry, Faculty of Science, University of Peradeniya Peradeniya 20400 Sri Lanka
| | - L L K Perera
- Department of Chemistry, Faculty of Science, University of Peradeniya Peradeniya 20400 Sri Lanka
| | - D Velauthapillai
- Advanced Nanomaterials for Clean Energy and Health Applications, Faculty of Engineering and Science, Western Norway University of Applied Sciences Campus Bergen, Kronstad Bergen D412 Norway
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Wang F, Sun Y, Cheng J. Switching of Redox Levels Leads to High Reductive Stability in Water-in-Salt Electrolytes. J Am Chem Soc 2023; 145:4056-4064. [PMID: 36758145 DOI: 10.1021/jacs.2c11793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Developing nonflammable electrolytes with wide electrochemical windows is of great importance for energy storage devices. Water-in-salt electrolytes (WiSE) have attracted great interests due to their widely opened electrochemical windows and high stability. Previous theoretical investigations have revealed changes in solvation shell of water molecules result in opening of HOMO-LUMO gaps of water, leading to the formation of an anion-derived solid-electrolyte-interphase (SEI) in WiSE. However, how solvation structures affect electrochemical windows at atomic level is still a puzzle, which hinders optimization and design of aqueous electrolytes. Herein, machine learning molecular dynamics and free energy calculation method are applied to compute redox potentials of anions of Li-salts and water of aqueous electrolytes at a range of salt concentrations. Furthermore, an analysis based on local solvation structures is employed to demonstrate the structure-property relations. Our calculation shows that the hydrogen evolution reaction is impeded in WiSE due to switching of the order of redox levels of the anion and H2O, leading to formation of SEI and high reductive stability. Level switching is caused by the special solvation environments of isolated water molecules. Our work provides new insight into the electrochemistry of aqueous electrolytes which would benefit the electrolyte design in energy storage devices.
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Affiliation(s)
- Feng Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Yan Sun
- State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Jun Cheng
- State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
- Tan Kah Kee Innovation Laboratory, Xiamen 361005, China
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Benchmarking the Computed Proton Solvation Energy and Absolute Potential in Non-aqueous Solvents. Electrochim Acta 2023. [DOI: 10.1016/j.electacta.2022.141785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Busch M, Ahlberg E, Laasonen K. Universal Trends between Acid Dissociation Constants in Protic and Aprotic Solvents. Chemistry 2022; 28:e202201667. [PMID: 35791810 DOI: 10.1002/chem.202201667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Indexed: 01/07/2023]
Abstract
pKa values in non-aqueous solvents are of critical importance in many areas of chemistry. Our knowledge is, despite their relevance, still limited to the most fundamental properties and few pKa values in the most common solvents. Taking advantage of a recently introduced computationally efficient procedure we computed the pKa values of 182 compounds in 21 solvents. This data set is used to establish for the first time universal trends between all solvents. Our computations indicate, that the total charge of the molecule and the charge of the acidic group combined with the Kamlet-Taft solvatochromic parameters are sufficient to predict pKa values with at least semi- quantitative accuracy. We find, that neutral acids such as alcohols are strongly affected by the solvent properties. This is contrasted by cationic acids like ammonium ions whose pKa is often almost completely independent from the choice of solvent.
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Affiliation(s)
- Michael Busch
- Institute of theoretical chemistry, Ulm University, Albert-Einstein Allee 11, 89069, Ulm, Germany
- Department of chemistry and material science, School of chemical engineering, Aalto University, Kemistintie 1, 02150, Espoo, Finland
| | - Elisabet Ahlberg
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemigården 4, 41296, Gothenburg, Sweden
| | - Kari Laasonen
- Department of chemistry and material science, School of chemical engineering, Aalto University, Kemistintie 1, 02150, Espoo, Finland
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Wang F, Cheng J. Unraveling the origin of reductive stability of super-concentrated electrolytes from first principles and unsupervised machine learning. Chem Sci 2022; 13:11570-11576. [PMID: 36320382 PMCID: PMC9557245 DOI: 10.1039/d2sc04025e] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/07/2022] [Indexed: 03/28/2024] Open
Abstract
Developing electrolytes with excellent electrochemical stability is critical for next-generation rechargeable batteries. Super-concentrated electrolytes (SCEs) have attracted great interest due to their high electrochemical performances and stability. Previous studies have revealed changes in solvation structures and shifts in lowest unoccupied molecular orbitals from solvents to anions, promoting the formation of an anion-derived solid-electrolyte-interphase (SEI) in SCE. However, a direct connection at the atomic level to electrochemical properties is still missing, hindering the rational optimization of electrolytes. Herein, we combine ab initio molecular dynamics with the free energy calculation method to compute redox potentials of propylene carbonate electrolytes at a range of LiTFSI concentrations, and moreover employ an unsupervised machine learning model with a local structure descriptor to establish the structure-property relations. Our calculation indicates that the network of TFSI- in SCE not only helps stabilize the added electron and renders the anion more prone to reductive decomposition, but also impedes the solvation of F- and favors LiF precipitation, together leading to effective formation of protective SEI layers. Our work provides new insights into the solvation structures and electrochemistry of concentrated electrolytes which are essential to electrolyte design in batteries.
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Affiliation(s)
- Feng Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Chemistry and Chemical Engineering, Xiamen University Xiamen 361005 China
| | - Jun Cheng
- State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Chemistry and Chemical Engineering, Xiamen University Xiamen 361005 China
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Busch M, Ahlberg E, Ahlberg E, Laasonen K. How to Predict the p K a of Any Compound in Any Solvent. ACS OMEGA 2022; 7:17369-17383. [PMID: 35647457 PMCID: PMC9134414 DOI: 10.1021/acsomega.2c01393] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 04/27/2022] [Indexed: 06/15/2023]
Abstract
Acid-base properties of molecules in nonaqueous solvents are of critical importance for almost all areas of chemistry. Despite this very high relevance, our knowledge is still mostly limited to the pK a of rather few compounds in the most common solvents, and a simple yet truly general computational procedure to predict pK a's of any compound in any solvent is still missing. In this contribution, we describe such a procedure. Our method requires only the experimental pK a of a reference compound in water and a few standard quantum-chemical calculations. This method is tested through computing the proton solvation energy in 39 solvents and by comparing the pK a of 142 simple compounds in 12 solvents. Our computations indicate that the method to compute the proton solvation energy is robust with respect to the detailed computational setup and the construction of the solvation model. The unscaled pK a's computed using an implicit solvation model on the other hand differ significantly from the experimental data. These differences are partly associated with the poor quality of the experimental data and the well-known shortcomings of implicit solvation models. General linear scaling relationships to correct this error are suggested for protic and aprotic media. Using these relationships, the deviations between experiment and computations drop to a level comparable to that observed in water, which highlights the efficiency of our method.
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Affiliation(s)
- Michael Busch
- Department
of Chemistry and Material Science, School of Chemical Engineering, Aalto University, Kemistintie 1, 02150 Espoo, Finland
| | - Ernst Ahlberg
- Universal
Prediction AB, 42677 Gothenburg, Sweden
- Department
of Pharmaceutical Biosciences, Uppsala University, Husargatan 3, 75124 Uppsala, Sweden
| | - Elisabet Ahlberg
- Department
of Chemistry and Molecular Biology, University
of Gothenburg, Kemigården 4, 41296 Gothenburg, Sweden
| | - Kari Laasonen
- Department
of Chemistry and Material Science, School of Chemical Engineering, Aalto University, Kemistintie 1, 02150 Espoo, Finland
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Gibson LD, Pfaendtner J, Mundy CJ. Probing the thermodynamics and kinetics of ethylene carbonate reduction at the electrode-electrolyte interface with molecular simulations. J Chem Phys 2021; 155:204703. [PMID: 34852482 DOI: 10.1063/5.0067687] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Understanding the formation of the solid-electrolyte interphase (SEI) in lithium-ion batteries is an ongoing area of research due to its high degree of complexity and the difficulties encountered by experimental studies. Herein, we investigate the initial stage of SEI growth, the reduction reaction of ethylene carbonate (EC), from both a thermodynamic and a kinetic approach with theory and molecular simulations. We employed both the potential distribution theorem and the Solvation Method based on Density (SMD) to EC solvation for the estimation of reduction potentials of Li+, EC, and Li+-solvating EC (s-EC) as well as reduction rate constants of EC and s-EC. We find that solvation effects greatly influence these quantities of interest, particularly the Li+/Li reference electrode potential in EC solvent. Furthermore, we also compute the inner- and outer-sphere reorganization energies for both EC and s-EC at the interface of liquid EC and a hydroxyl-terminated graphite surface, where total reorganization energies are predicted to be 76.6 and 88.9 kcal/mol, respectively. With the computed reorganization energies, we estimate reduction rate constants across a range of overpotentials and show that EC has a larger electron transfer rate constant than s-EC at equilibrium, despite s-EC being more thermodynamically favorable. Overall, this manuscript demonstrates how ion solvation effects largely govern the prediction of reduction potentials and electron transfer rate constants at the electrode-electrolyte interface.
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Affiliation(s)
- Luke D Gibson
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, USA
| | - Jim Pfaendtner
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, USA
| | - Christopher J Mundy
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, USA
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