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Liu C, Qin X, Yu C, Guo Y, Zhang Z. Probing the adsorption configuration of methanol at a charged air/aqueous interface using nonlinear spectroscopy. Phys Chem Chem Phys 2024; 26:14336-14344. [PMID: 38699833 DOI: 10.1039/d3cp06317h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2024]
Abstract
Investigating the effects of electrolyte ions on the adsorption configuration of methanol at a charged interface is important for studying the interface structure of electrolyte solutions and the oxidation mechanism of methanol in fuel cells. This study uses sum frequency generation (SFG) and heterodyne-detected second harmonic generation (HD-SHG) to investigate the adsorption configuration of methanol at the air/aqueous interface of 0.1 M NaClO4 solution, 0.1 M HClO4 solution and pure water. The results elucidate that the ion effect in the electrolyte solution affects the interface's charged state and the methanol's adsorption conformation at the interface. The negatively charged surface of the 0.1 M NaClO4 solution and the positively charged surface of the 0.1 M HClO4 solution arise from the corresponding specific ionic effects of the electrolyte solution. The orientation angle of methyl with respect to the surface normal is 43.4° ± 0.1° at the 0.1 M NaClO4 solution surface and 21.5° ± 0.2° at the 0.1 M HClO4 solution surface. Examining these adsorption configurations in detail, we find that at the negatively charged surface the inclined orientation angle (43.4°) of methanol favors the hydroxymethyl production by breaking the C-H bond, while at the positively charged surface the upright orientation angle (21.5°) of methanol promotes the methoxy formation by breaking the O-H bond. These findings not only illuminate the intricate ion effects on small organic molecules but also contribute to a molecular-level comprehension of the oxidation mechanism of methanol at electrode interfaces.
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Affiliation(s)
- Caihe Liu
- Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Molecular Reaction Dynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Xujin Qin
- Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Molecular Reaction Dynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Changhui Yu
- Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Molecular Reaction Dynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Yuan Guo
- Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Molecular Reaction Dynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Zhen Zhang
- Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Molecular Reaction Dynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
- University of the Chinese Academy of Sciences, Beijing 100049, China
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Engelbrecht LDV, Ji X, Carbonaro CM, Laaksonen A, Mocci F. MD simulations explain the excess molar enthalpies in pseudo-binary mixtures of a choline chloride-based deep eutectic solvent with water or methanol. Front Chem 2022; 10:983281. [DOI: 10.3389/fchem.2022.983281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 10/28/2022] [Indexed: 11/16/2022] Open
Abstract
The addition of molecular liquid cosolvents to choline chloride (ChCl)-based deep eutectic solvents (DESs) is increasingly investigated for reducing the inherently high bulk viscosities of the latter, which represent a major obstacle for potential industrial applications. The molar enthalpy of mixing, often referred to as excess molar enthalpy HE—a property reflecting changes in intermolecular interactions upon mixing—of the well-known ChCl/ethylene glycol (1:2 molar ratio) DES mixed with either water or methanol was recently found to be of opposite sign at 308.15 K: Mixing of the DES with water is strongly exothermic, while methanol mixtures are endothermic over the entire mixture composition range. Knowledge of molecular-level liquid structural changes in the DES following cosolvent addition is expected to be important when selecting such “pseudo-binary” mixtures for specific applications, e.g., solvents. With the aim of understanding the reason for the different behavior of selected DES/water or methanol mixtures, we performed classical MD computer simulations to study the changes in intermolecular interactions thought to be responsible for the observed HE sign difference. Excess molar enthalpies computed from our simulations reproduce, for the first time, the experimental sign difference and composition dependence of the property. We performed a structural analysis of simulation configurations, revealing an intriguing difference in the interaction modes of the two cosolvents with the DES chloride anion: water molecules insert between neighboring chloride anions, forming ionic hydrogen-bonded bridges that draw the anions closer, whereas dilution of the DES with methanol results in increased interionic separation. Moreover, the simulated DES/water mixtures were found to contain extended hydrogen-bonded structures containing water-bridged chloride pair arrangements, the presence of which may have important implications for solvent applications.
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3
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Boukar O, Fifen JJ, Malloum A, Nsangou M, Ghalila H, Conradie J. Solvation energies of ferrous ion in methanol at various temperatures. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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4
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Fujii A, Sugawara N, Hsu PJ, Shimamori T, Li YC, Hamashima T, Kuo JL. Hydrogen bond network structures of protonated short-chain alcohol clusters. Phys Chem Chem Phys 2018; 20:14971-14991. [DOI: 10.1039/c7cp08072g] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Protonated alcohol clusters enable extraction of the physical essence of the nature of hydrogen bond networks.
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Affiliation(s)
- Asuka Fujii
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Natsuko Sugawara
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Po-Jen Hsu
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
| | - Takuto Shimamori
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Ying-Cheng Li
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
| | - Toru Hamashima
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Jer-Lai Kuo
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
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5
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Faralli C, Pagliai M, Cardini G, Schettino V. Ab Initio Molecular Dynamics Study of Mg(2+) and Ca(2+) Ions in Liquid Methanol. J Chem Theory Comput 2015; 4:156-63. [PMID: 26619989 DOI: 10.1021/ct700209v] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ab initio Car-Parrinello molecular dynamics simulations have been performed in order to investigate the solvation properties of Mg(2+) and Ca(2+) in fully deuterated methanol solution to better understand polarization effects induced by the ions. Charge transfer and dipole moment calculations have been performed to give more detailed insight on the role of the electronic reorganization and its effect on the first solvation shell stability. The perturbation of the methanol H-bond network has been investigated.
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Affiliation(s)
- Cristian Faralli
- Laboratorio di Spettroscopia Molecolare, Dipartimento di Chimica, Università di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino, Firenze, Italia, and European Laboratory for Nonlinear Spectroscopy (LENS), via Nello Carrara 1, 50019 Sesto Fiorentino, Firenze, Italia
| | - Marco Pagliai
- Laboratorio di Spettroscopia Molecolare, Dipartimento di Chimica, Università di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino, Firenze, Italia, and European Laboratory for Nonlinear Spectroscopy (LENS), via Nello Carrara 1, 50019 Sesto Fiorentino, Firenze, Italia
| | - Gianni Cardini
- Laboratorio di Spettroscopia Molecolare, Dipartimento di Chimica, Università di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino, Firenze, Italia, and European Laboratory for Nonlinear Spectroscopy (LENS), via Nello Carrara 1, 50019 Sesto Fiorentino, Firenze, Italia
| | - Vincenzo Schettino
- Laboratorio di Spettroscopia Molecolare, Dipartimento di Chimica, Università di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino, Firenze, Italia, and European Laboratory for Nonlinear Spectroscopy (LENS), via Nello Carrara 1, 50019 Sesto Fiorentino, Firenze, Italia
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Kumar P, Kulkarni AD, Yashonath S. Influence of a Counterion on the Ion Atmosphere of an Anion: A Molecular Dynamics Study of LiX and CsX (X = F–, Cl–, I–) in Methanol. J Phys Chem B 2015; 119:10921-33. [DOI: 10.1021/acs.jpcb.5b00481] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Parveen Kumar
- Solid
State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Anant D. Kulkarni
- Centre
for Computational Materials Science, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India
| | - S. Yashonath
- Solid
State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
- Center
for Condensed Matter Theory, Indian Institute of Science, Bangalore 560012, India
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Hassanali AA, Cuny J, Verdolino V, Parrinello M. Aqueous solutions: state of the art in ab initio molecular dynamics. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2014; 372:20120482. [PMID: 24516179 DOI: 10.1098/rsta.2012.0482] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The simulation of liquids by ab initio molecular dynamics (AIMD) has been a subject of intense activity over the last two decades. The significant increase in computational resources as well as the development of new and efficient algorithms has elevated this method to the status of a standard quantum mechanical tool that is used by both experimentalists and theoreticians. As AIMD computes the electronic structure from first principles, it is free of ad hoc parametrizations and has thus been applied to a large variety of physical and chemical problems. In particular, AIMD has provided microscopic insight into the structural and dynamical properties of aqueous solutions which are often challenging to probe experimentally. In this review, after a brief theoretical description of the Born-Oppenheimer and Car-Parrinello molecular dynamics formalisms, we show how AIMD has enhanced our understanding of the properties of liquid water and its constituent ions: the proton and the hydroxide ion. Thereafter, a broad overview of the application of AIMD to other aqueous systems, such as solvated organic molecules and inorganic ions, is presented. We also briefly describe the latest theoretical developments made in AIMD, such as methods for enhanced sampling and the inclusion of nuclear quantum effects.
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Affiliation(s)
- Ali A Hassanali
- Department of Chemistry and Applied Biosciences, ETH Zurich and Università della Svizzera Italiana, , via G. Buffi 13, 6900 Lugano, Switzerland
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8
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Bogatko S, Cauët E, Geerlings P, De Proft F. On the coupling of solvent characteristics to the electronic structure of solute molecules. Phys Chem Chem Phys 2014; 16:3807-14. [PMID: 24435016 DOI: 10.1039/c3cp54944e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We present the results of a theoretical investigation focusing on the solvent structure surrounding the -1, 0 and +1 charged species of F, Cl, Br and I halogen atoms and F2, Cl2, Br2 and I2 di-halogen molecules in a methanol solvent and its influence on the electronic structure of the solute molecules. Our results show a large stabilizing effect arising from the solute-solvent interactions. Well-formed first solvation shells are observed for all species, the structure of which is strongly influenced by the charge of the solute species. Detailed analysis reveals that coordination number, CN, solvent orientation, θ, and solute-solvent distance, d, are important structural characteristics which are coupled to changes in the electronic structure of the solute. We propose that the fundamental chemistry of any solute species is generally regulated by these solvent degrees of freedom.
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Affiliation(s)
- Stuart Bogatko
- Eenheid Algemene Chemie, Vrije Universiteit Brussel (VUB), Faculteit Wetenschappen, Pleinlaan 2, 1050 Brussels, Belgium.
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9
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Muniz-Miranda F, Pagliai M, Cardini G, Righini R. Hydrogen bond effects in the vibrational spectra of 1,3-propanediol in acetonitrile:Ab initioand experimental study. J Chem Phys 2012; 137:244501. [DOI: 10.1063/1.4770499] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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10
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Ferreira JAB, Sánchez-Coronilla A, Togashi DM, Ferreira H, Ascenso JR, Costa SMB. Electrophilic reactivity of tetrabromorhodamine 123 is bromine induced: convergent interpretation through complementary molecular descriptors. J Phys Chem A 2012; 116:11938-45. [PMID: 23134615 DOI: 10.1021/jp307461m] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Nucleophilic addition of water and of methanol to 3,6-diamino-2,4,5,7-tetrabromo-9-[2-(methoxycarbonyl) phenyl]-9H-xanthen-9-ylium, 4BrR123, yields respectively 2-(3,6-diamino-2,4,5,7-tetrabromo-9-hydroxy-9H-xanthen-9-yl)xanthyl benzoate, HO4BrR123 and 2-(3,6-diamino-2,4,5,7-tetrabromo-9-methoxy-9H-xanthen-9-yl)xanthyl benzoate, MeO4BrR123. The novel experimental results are addressed theoretically. The linear free energy relationship, LFER, second-order perturbation theory analysis of the natural bond orbital, NBO, and quantum theory of atoms in molecules, QTAIM, lead to the same conclusion: the electron-withdrawing effect of bonded Br atoms in 4BrR123 extremely enhances the molecular electrophilicity, as compared to 3,6-diamino-9-[2-(methoxycarbonyl) phenyl]-9H-xanthen-9-ylium, R123. The reactivity of these diaminoxanthylium cations is discussed in the context of local and global softness in extended conjugated systems.
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Affiliation(s)
- José A B Ferreira
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade Técnica de Lisboa, Portugal.
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11
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Chi CX, Xie H, Cong R, Tang ZC, Zhou MF. Photoelectron Imaging of AgOCH3− and Ag−(CH3OH)x (x = 1, 2). CHINESE J CHEM PHYS 2011. [DOI: 10.1088/1674-0068/24/05/557-562] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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12
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Muniz-Miranda F, Pagliai M, Cardini G, Schettino V. Wavelet Transform for Spectroscopic Analysis: Application to Diols in Water. J Chem Theory Comput 2011; 7:1109-18. [PMID: 26606359 DOI: 10.1021/ct100625e] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Wavelet transform has been used to correlate spectroscopic and structural properties from trajectories obtained by ab initio molecular dynamics simulations. This method has been applied to hydrogen bond dynamics of glycols in heavy water solutions, showing how the stretching frequency of the intramolecular O-H bond changes with the intermolecular hydrogen-bond distance. The resulting wavelet spectrograms have been interpreted according to H-bond strength and stability.
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Affiliation(s)
- Francesco Muniz-Miranda
- European Laboratory for Non-Linear Spectroscopy (LENS), via Nello Carrara 1, 50019, Sesto Fiorentino (FI), Italy
| | - Marco Pagliai
- Dipartimento di Chimica "Ugo Schiff", Università degli Studi di Firenze, via della Lastruccia 3, 50019, Sesto Fiorentino (FI), Italy
| | - Gianni Cardini
- European Laboratory for Non-Linear Spectroscopy (LENS), via Nello Carrara 1, 50019, Sesto Fiorentino (FI), Italy.,Dipartimento di Chimica "Ugo Schiff", Università degli Studi di Firenze, via della Lastruccia 3, 50019, Sesto Fiorentino (FI), Italy
| | - Vincenzo Schettino
- European Laboratory for Non-Linear Spectroscopy (LENS), via Nello Carrara 1, 50019, Sesto Fiorentino (FI), Italy.,Dipartimento di Chimica "Ugo Schiff", Università degli Studi di Firenze, via della Lastruccia 3, 50019, Sesto Fiorentino (FI), Italy
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13
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Sun X, Wick CD, Dang LX. Computational Study of Ion Distributions at the Air/Liquid Methanol Interface. J Phys Chem A 2010; 115:5767-73. [DOI: 10.1021/jp107563e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Xiuquan Sun
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Collin D. Wick
- Louisiana Tech University, Ruston, Louisiana 71270, United States
| | - Liem X. Dang
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
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14
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Candelaresi M, Pagliai M, Lima M, Righini R. Chemical Equilibrium Probed by Two-Dimensional IR Spectroscopy: Hydrogen Bond Dynamics of Methyl Acetate in Water. J Phys Chem A 2009; 113:12783-90. [DOI: 10.1021/jp906072w] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Marco Candelaresi
- European Laboratory for Nonlinear Spectroscopy (LENS), Via Nello Carrara 1, and Dipartimento di Chimica, Università di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino (Fi), Italy
| | - Marco Pagliai
- European Laboratory for Nonlinear Spectroscopy (LENS), Via Nello Carrara 1, and Dipartimento di Chimica, Università di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino (Fi), Italy
| | - Manuela Lima
- European Laboratory for Nonlinear Spectroscopy (LENS), Via Nello Carrara 1, and Dipartimento di Chimica, Università di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino (Fi), Italy
| | - Roberto Righini
- European Laboratory for Nonlinear Spectroscopy (LENS), Via Nello Carrara 1, and Dipartimento di Chimica, Università di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino (Fi), Italy
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15
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Pagliai M, Muniz-Miranda M, Cardini G, Schettino V. Solvation Dynamics and Adsorption on Ag Hydrosols of Oxazole: A Raman and Computational Study. J Phys Chem A 2009; 113:15198-205. [DOI: 10.1021/jp905530x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Marco Pagliai
- Dipartimento di Chimica, Università di Firenze, via della Lastruccia 3, 50019 Sesto Fiorentino, Italia, and European Laboratory for Nonlinear Spectroscopy (LENS), via Nello Carrara 1, 50019 Sesto Fiorentino, Italia
| | - Maurizio Muniz-Miranda
- Dipartimento di Chimica, Università di Firenze, via della Lastruccia 3, 50019 Sesto Fiorentino, Italia, and European Laboratory for Nonlinear Spectroscopy (LENS), via Nello Carrara 1, 50019 Sesto Fiorentino, Italia
| | - Gianni Cardini
- Dipartimento di Chimica, Università di Firenze, via della Lastruccia 3, 50019 Sesto Fiorentino, Italia, and European Laboratory for Nonlinear Spectroscopy (LENS), via Nello Carrara 1, 50019 Sesto Fiorentino, Italia
| | - Vincenzo Schettino
- Dipartimento di Chimica, Università di Firenze, via della Lastruccia 3, 50019 Sesto Fiorentino, Italia, and European Laboratory for Nonlinear Spectroscopy (LENS), via Nello Carrara 1, 50019 Sesto Fiorentino, Italia
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16
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Brastad SM, Albert DR, Huang M, Nathanson GM. Collisions of DCl with a Solution Covered with Hydrophobic and Hydrophilic Ions: Tetrahexylammonium Bromide in Glycerol. J Phys Chem A 2009; 113:7422-30. [DOI: 10.1021/jp900232v] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Susan M. Brastad
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706-1322
| | - Daniel R. Albert
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706-1322
| | - Mingwei Huang
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706-1322
| | - Gilbert M. Nathanson
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706-1322
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17
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Chan SJ, Howe AG, Hook JM, Harper JB. (79)Br NMR spectroscopy as a practical tool for kinetic analysis. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2009; 47:342-347. [PMID: 19189283 DOI: 10.1002/mrc.2401] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
(79)Br NMR spectroscopy has been used to monitor a series of reactions in which the bromide ion is produced, including the Menschutkin reaction of pyridine with a range of substituted benzyl bromides and a Heck coupling process. In cases where the process could also be monitored using (1)H NMR spectroscopy, the kinetic analyses using heteronuclear magnetic resonance spectroscopy were shown to be completely consistent. Both the utility of the process in following reactions which may be difficult to analyse using other techniques and the practical limitations associated with solvent choice are discussed.
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Affiliation(s)
- Si Jia Chan
- School of Chemistry, University of New South Wales, Sydney NSW 2052, Australia
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18
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Suzuki Y, Kaneno D, Tomoda S. Theoretical Study on the Mechanism and Diastereoselectivity of NaBH4 Reduction. J Phys Chem A 2009; 113:2578-83. [DOI: 10.1021/jp809966u] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yasumitsu Suzuki
- Department of Life Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan
| | - Daisuke Kaneno
- Department of Life Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan
| | - Shuji Tomoda
- Department of Life Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan
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Stuart CM, Tauber MJ, Mathies RA. Structure and Dynamics of the Solvated Electron in Alcohols from Resonance Raman Spectroscopy. J Phys Chem A 2007; 111:8390-400. [PMID: 17676822 DOI: 10.1021/jp068283q] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Resonance Raman (RR) spectroscopy is used to probe the structure and excited-state dynamics of the solvated electron in the primary liquid alcohols methanol (MeOH), ethanol (EtOH), n-propanol (n-PrOH), and n-butanol (n-BuOH). The strong resonance enhancements (>or=10(4) relative to pure solvent) of the libration, CO stretch, COH bend, CH3 bend, CH2 bend, and OH stretch reveal significant Franck-Condon coupling of the intermolecular and intramolecular vibrational modes of the solvent to the electronic excitation of the solvated electron. All enhanced bands are fully accounted for by a model of the solvated electron that is comprised of several nearby solvent molecules that are only perturbed by the presence of the electron; no new molecular species are required to explain our data. The 340 cm(-1) downshift observed for the OH stretch frequency of e-(MeOH), relative to pure solvent, strongly suggests that the methanol molecules in the first solvent shell have the hydroxyl group directed linearly toward the excess electron density. The smaller downshifts observed for e-(EtOH), e-(n-PrOH), and e-(n-BuOH) are explained in terms of a OH group that is bent 28-40 degrees from linear. The Raman cross sections and absorption spectra are modeled, lending quantitative support for the inhomogeneous origin of the broad absorption spectra, the necessity of OH local motion in all enhanced Raman modes of the alcohols, and the dominant librational response of the solvent upon photoexcitation of the electron.
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Affiliation(s)
- Christina M Stuart
- Department of Chemistry, University of California, Berkeley, California 94720, USA
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20
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Faralli C, Pagliai M, Cardini G, Schettino V. The solvation dynamics of Na+ and K+ ions in liquid methanol. Theor Chem Acc 2007. [DOI: 10.1007/s00214-007-0286-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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21
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Suresh SJ, Prabhu AL, Arora A. Influence of electric field on the hydrogen bond network of methanol. J Chem Phys 2007; 126:134502. [PMID: 17430042 DOI: 10.1063/1.2647105] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The understanding of the structure of hydrogen (H) bonding liquids in electric (E) fields is important in the context of several areas of research, such as electrochemistry, surface science, and thermodynamics of electrolyte solutions. We had earlier presented a general thermodynamic framework for this purpose, and had shown that the application of E field enhances H-bond interactions among water molecules. The present investigation with methanol suggests a different result-the H-bond structure, as indicated by the average number of H bonds per molecule, goes through a maxima with increasing field strength. This result is explained based on the symmetry in the location of the H-bonding sites in the two types of molecules.
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Affiliation(s)
- S J Suresh
- Unilever Research India, 64 Main Road, Whitefield, Bangalore 560066, India.
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Schettino V, Chelli R, Marsili S, Barducci A, Faralli C, Pagliai M, Procacci P, Cardini G. Problems in molecular dynamics of condensed phases. Theor Chem Acc 2007. [DOI: 10.1007/s00214-006-0223-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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