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Sharma B, Tran VA, Pongratz T, Galazzo L, Zhurko I, Bordignon E, Kast SM, Neese F, Marx D. A Joint Venture of Ab Initio Molecular Dynamics, Coupled Cluster Electronic Structure Methods, and Liquid-State Theory to Compute Accurate Isotropic Hyperfine Constants of Nitroxide Probes in Water. J Chem Theory Comput 2021; 17:6366-6386. [PMID: 34516119 PMCID: PMC8515807 DOI: 10.1021/acs.jctc.1c00582] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Indexed: 01/11/2023]
Abstract
The isotropic hyperfine coupling constant (HFCC, Aiso) of a pH-sensitive spin probe in a solution, HMI (2,2,3,4,5,5-hexamethylimidazolidin-1-oxyl, C9H19N2O) in water, is computed using an ensemble of state-of-the-art computational techniques and is gauged against X-band continuous wave electron paramagnetic resonance (EPR) measurement spectra at room temperature. Fundamentally, the investigation aims to delineate the cutting edge of current first-principles-based calculations of EPR parameters in aqueous solutions based on using rigorous statistical mechanics combined with correlated electronic structure techniques. In particular, the impact of solvation is described by exploiting fully atomistic, RISM integral equation, and implicit solvation approaches as offered by ab initio molecular dynamics (AIMD) of the periodic bulk solution (using the spin-polarized revPBE0-D3 hybrid functional), embedded cluster reference interaction site model integral equation theory (EC-RISM), and polarizable continuum embedding (using CPCM) of microsolvated complexes, respectively. HFCCs are obtained from efficient coupled cluster calculations (using open-shell DLPNO-CCSD theory) as well as from hybrid density functional theory (using revPBE0-D3). Re-solvation of "vertically desolvated" spin probe configuration snapshots by EC-RISM embedding is shown to provide significantly improved results compared to CPCM since only the former captures the inherent structural heterogeneity of the solvent close to the spin probe. The average values of the Aiso parameter obtained based on configurational statistics using explicit water within AIMD and from EC-RISM solvation are found to be satisfactorily close. Using either such explicit or RISM solvation in conjunction with DLPNO-CCSD calculations of the HFCCs provides an average Aiso parameter for HMI in aqueous solution at 300 K and 1 bar that is in good agreement with the experimentally determined one. The developed computational strategy is general in the sense that it can be readily applied to other spin probes of similar molecular complexity, to aqueous solutions beyond ambient conditions, as well as to other solvents in the longer run.
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Affiliation(s)
- Bikramjit Sharma
- Lehrstuhl
für Theoretische Chemie, Ruhr-Universität
Bochum, 44780 Bochum, Germany
| | - Van Anh Tran
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Tim Pongratz
- Physikalische
Chemie III, Technische Universität
Dortmund, Otto-Hahn-Str. 4a, 44227 Dortmund, Germany
| | - Laura Galazzo
- Faculty
of Chemistry and Biochemistry, Ruhr University
Bochum, 44780 Bochum, Germany
| | - Irina Zhurko
- Laboratory
of Nitrogen Compounds, N.N. Vorozhtsov Novosibirsk Institute of Organic
Chemistry, NIOCH SB RAS, 9 Lavrentiev Avenue, 630090, Novosibirsk, Russia
| | - Enrica Bordignon
- Faculty
of Chemistry and Biochemistry, Ruhr University
Bochum, 44780 Bochum, Germany
| | - Stefan M. Kast
- Physikalische
Chemie III, Technische Universität
Dortmund, Otto-Hahn-Str. 4a, 44227 Dortmund, Germany
| | - Frank Neese
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Dominik Marx
- Lehrstuhl
für Theoretische Chemie, Ruhr-Universität
Bochum, 44780 Bochum, Germany
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Novotný J, Sojka M, Komorovsky S, Nečas M, Marek R. Interpreting the Paramagnetic NMR Spectra of Potential Ru(III) Metallodrugs: Synergy between Experiment and Relativistic DFT Calculations. J Am Chem Soc 2016; 138:8432-45. [DOI: 10.1021/jacs.6b02749] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jan Novotný
- CEITEC − Central European Institute
of Technology, Masaryk University, Kamenice 5, CZ − 62500 Brno, Czech Republic
| | - Martin Sojka
- CEITEC − Central European Institute
of Technology, Masaryk University, Kamenice 5, CZ − 62500 Brno, Czech Republic
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, CZ − 62500 Brno, Czech Republic
| | - Stanislav Komorovsky
- Centre for
Theoretical and Computational Chemistry, Department of Chemistry, UiT − The Arctic University of Norway, N-9037 Tromsø, Norway
| | - Marek Nečas
- CEITEC − Central European Institute
of Technology, Masaryk University, Kamenice 5, CZ − 62500 Brno, Czech Republic
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, CZ − 62500 Brno, Czech Republic
| | - Radek Marek
- CEITEC − Central European Institute
of Technology, Masaryk University, Kamenice 5, CZ − 62500 Brno, Czech Republic
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, CZ − 62500 Brno, Czech Republic
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McKenzie I, Scheuermann R, Cottrell SP, Lord JS, Tucker IM. Hyperfine coupling constants of the cyclohexadienyl radical in benzene and dilute aqueous solution. J Phys Chem B 2013; 117:13614-8. [PMID: 24144160 DOI: 10.1021/jp4068763] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The muon hyperfine coupling constant (Aμ) of the muoniated cyclohexadienyl radical (C6H6Mu) has been directly measured in a 5 mM solution of benzene in water by the radio-frequency muon spin resonance (RF-μSR) technique. The relative shift of Aμ in aqueous solution compared with the value in neat benzene (ΔAμ/Aμ = +0.98(5)% at 293 K) can now be compared directly with theoretical predictions. Application of the RF-μSR method to other dilute systems will provide extremely important information on understanding solvent effects.
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Affiliation(s)
- Iain McKenzie
- Centre for Molecular and Materials Science, TRIUMF , 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
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McKenzie I. The positive muon and μSR spectroscopy: powerful tools for investigating the structure and dynamics of free radicals and spin probes in complex systems. ACTA ACUST UNITED AC 2013. [DOI: 10.1039/c3pc90005c] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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McKenzie I, Dilger H, Roduner E, Scheuermann R, Zimmermann U. Solvation of a Hydrogen Isotope in Aqueous Methanol, NaCl, and KCl Solutions. J Phys Chem B 2008; 112:3070-6. [DOI: 10.1021/jp0769882] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Iain McKenzie
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany, and Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - Herbert Dilger
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany, and Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - Emil Roduner
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany, and Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - Robert Scheuermann
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany, and Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - Ulrich Zimmermann
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany, and Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
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Lauzon JM, Arseneau DJ, Brodovitch JC, Clyburne JAC, Cormier P, McCollum B, Ghandi K. Generation and detection of the cyclohexadienyl radical in phosphonium ionic liquids. Phys Chem Chem Phys 2008; 10:5957-62. [DOI: 10.1039/b804800b] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Vujosevi Cacute D, Dilger H, McKenzie I, Martyniak A, Scheuermann R, Roduner E. Local Ordering in Liquids: Solvent Effects on the Hyperfine Couplings of the Cyclohexadienyl Radical. J Phys Chem B 2007; 111:199-208. [PMID: 17201444 DOI: 10.1021/jp065488q] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Ordering of solvent molecules in the vicinity of a dipolar free radical affects its hyperfine coupling constants (hfcs). Specifically, it is demonstrated how the variation of the experimental methylene proton and muon hfcs of the muoniated cyclohexadienyl radical in several solvents and solvent mixtures of varying polarity can be accounted for by a dipole-dipole reaction field model that is based on the model of Reddoch and Konishi (J. Chem. Phys. 1979, 70, 2121) which was developed to explain the solvent dependence of the 14N hfc in the di-tert-butyl-nitroxide radical. Ab initio calculations were carried out with the cyclohexadienyl radical in an electric field to model the electric field arising from the electric dipole moments of the surrounding solvent molecules. An extension of the model that includes the dipole-quadrupole interaction can account for the larger hfc in benzene compared with that in octadecane, and it is predicted that the hfc will be proportional to the concentration of quadrupole moments to the 4/3 power. The influence of hydrogen bonding between the radicals' pi electrons and the OH groups of the solvent on the hfcs is also discussed. Comparison with gas-phase data permits a separation of vibrational effects and reveals that approximately 28% of the temperature dependence in water is due to increasing solvent disorder.
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Affiliation(s)
- Danilo Vujosevi Cacute
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
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Martyniak A, Dilger H, Scheuermann R, Tucker IM, McKenzie I, Vujosevic D, Roduner E. Using spin polarised positive muons for studying guest molecule partitioning in soft matter structures. Phys Chem Chem Phys 2006; 8:4723-40. [PMID: 17043715 DOI: 10.1039/b610414b] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Fully polarised positive muons substituted for protons in organic free radicals can be used as spin labels which reveal information about the structure, dynamics and environment of these radicals. In applications via the technique of avoided-level-crossing muon spin resonance (ALC-microSR), the positive muon has been used to study the partitioning of phenyl alcohols in lamellar phase colloidal dispersions of a cationic dichain surfactant. Here we describe the experimental technique which permits highly sensitive spectroscopy as previously demonstrated for surfactant mixtures. We also demonstrate its capability in the study of partitioning of cosurfactant molecules in surfactant bilayers in order to elucidate the main factors which contribute to cosurfactant ordering at interfaces. The technique takes advantage of the positive muon combining with an electron to a hydrogen-like atom that is called muonium. This atom attaches to a phenyl group, forming a cyclohexadienyl-type radical that contains the muon as a polarised spin label, providing an excellent probe even for very low phenyl alcohol concentrations. The position of one type of resonance, which on the basis of spectroscopic selection rules is denoted as Delta(0), is related to the solvent polarity of the radicals' environment. The results derived from Delta(0) measurements reveal a systematic trend where the increasing chain length of the phenyl alcohol results in a deeper immersion of the phenyl ring of the alcohol into the surfactant bilayer with the OH group anchored at the interface. In addition, the data suggest partial penetration of water molecules into the bilayer. Furthermore, data ensuing from a second resonance (called Delta(1), which is dependent upon the degree of confinement of the radical within the surfactant aggregate structure) indicates not only that the phenyl alcohol resides in an anisotropic environment, (i.e. that the host molecule is unable to undergo full 3-D reorientation on a timescale of 50 ns), but the resonance line widths indicate that the radicals are undergoing fast rotation about a particular axis, in this instance about the first C-C substituent bond at the phenyl ring. Detailed analysis of these Delta(1) line shapes suggests that other types of motion involving reorientation of the above rotation axis are also present. At room temperature, the hydrocarbon chains of the double layers form an aggregate state commonly referred to as the L(beta) phase, where the motions of surfactant alkyl chains are effectively frozen out. These chains melt on heating over a temperature range which is solution composition dependent (ca. 51 to 67 degrees C), but in all cases leading to a liquid-like disordered hydrocarbon regime whilst retaining the overall lamellar structure (and in this state is termed L(alpha)). Above the L(alpha)/L(beta) chain ordering phase transition the tracer molecules reside within the bilayer, but below this transition (and depending on their water-oil solubility) they are completely or partly expelled. This interpretation is further supported by Heisenberg spin exchange experiments. The water-bilayer partitioning reflects both typical classical and nonclassical hydrophobic solvation depending on temperature and chain length of phenyl alcohols.
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Affiliation(s)
- A Martyniak
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569, Stuttgart, Germany
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