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Borovkov V. Simple relation for estimating the relative mobility of geminate ions using the influence of electric field on the geminate recombination. Chem Phys Lett 2009. [DOI: 10.1016/j.cplett.2009.10.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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2
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Ford MH, Auerbach SM, Monson PA. Further studies of a simple atomistic model of silica: Thermodynamic stability of zeolite frameworks as silica polymorphs. J Chem Phys 2007; 126:144701. [PMID: 17444726 DOI: 10.1063/1.2712440] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have applied our previously reported model of silica based on low coordination and strong association [J. Chem. Phys. 121, 8415 (2004)], to the calculation of phase stability of zeolite frameworks SOD, LTA, MFI, and FAU as silica polymorphs. We applied the method of Frenkel and Ladd for calculating free energies of these solids. Our model predicts that the MFI framework structure has a regime of thermodynamic stability at low pressures and above approximately 1400 K, relative to dense phases such as quartz. In contrast, our calculations predict that the less dense frameworks SOD, LTA, and FAU exhibit no regime of thermodynamic stability. We have also used our model to investigate whether templating extends the MFI regime of thermodynamic stability to lower temperatures, by considering templates with hard-sphere repulsions and mean-field attractions to silica. Within the assumptions of our model, we find that quartz remains the thermodynamically stable polymorph at zeolite synthesis temperatures (approximately 400 K) unless unphysically large template-silica attractions are assumed. These predictions suggest that some zeolites such as MFI may have regimes of thermodynamic stability even without template stabilization.
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Affiliation(s)
- Matthew H Ford
- Department of Chemical Engineering, University of Massachusetts, Amherst, Massachusetts 01003, USA
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Saeki A, Kozawa T, Ohnishi Y, Tagawa S. Reactivity between Biphenyl and Precursor of Solvated Electrons in Tetrahydrofuran Measured by Picosecond Pulse Radiolysis in Near-Ultraviolet, Visible, and Infrared. J Phys Chem A 2007; 111:1229-35. [PMID: 17256922 DOI: 10.1021/jp067520m] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The initial decrease of solvated electrons in tetrahydrofuran (THF) upon addition of biphenyl was investigated by picosecond pulse radiolysis. Transient absorption spectra derived from the biphenyl radical anion (centered at 408 and 655 nm) and solvated electrons of THF (infrared) were successfully measured in the wavelength region from 400 to 900 nm by the extension of a femtosecond continuum probe light to near-ultraviolet using a second harmonic generation of Ti:sapphire laser and a CaF2 plate. From the analysis of kinetic traces at 1300 nm considering the overlap of primary solvated electrons and partial biphenyl radical anion, C37, which is defined by the solute concentration to reduce the initial yield of solvated electrons to 1/e, was found to be 87 +/- 3 mM. The rate constant of solvated electrons with biphenyl was determined as 5.8 +/- 0.3 x 10(10) M(-1) s(-1). We demonstrate that the kinetic traces at both 408 nm mainly due to biphenyl radical anion and 1300 nm mainly due to solvated electrons are reproduced with high accuracy and consistency by a simple kinetic analysis. Much higher concentrations of biphenyl (up to 2 M) were examined, showing further increase of the initial yield of biphenyl radical anion accompanying a fast decay component. This observation is discussed in terms of geminate ion recombination, scavenging, delayed geminate ion recombination, and direct ionization of biphenyl at high concentration.
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Affiliation(s)
- Akinori Saeki
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan.
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Borovkov VI, Gritsan NP, Yeletskikh IV, Bagryansky VA, Molin YN. Degenerate Electron Exchange Reaction of n-Alkane Radical Cations in Solution. J Phys Chem A 2006; 110:12752-9. [PMID: 17125288 DOI: 10.1021/jp0638944] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The degenerate electron exchange (DEE) reaction involving radical cations (RCs) of n-nonane, n-dodecane, and n-hexadecane in n-hexane solution was studied over the temperature range 253-313 K using the method of time-resolved magnetic field effect in recombination fluorescence of spin-correlated radical ion pairs. In the dilute solutions the rate constant of DEE was found to be 200 times slower than the diffusion limit. Using n-nonane as an example, we showed that two reasons are responsible for the low value of the RC self-exchange rate: (1) conformational variability of molecules and RCs and (2) the activation barrier of DEE reaction. The calculations of the reaction enthalpy performed by the B3LYP/6-31G(d) method indicated that electron transfer can be effective only upon collision of RC with a neutral molecule either in the all-trans conformation or in the conformation differing from the latter by rotation of the end ethyl fragment. The activation barrier of the DEE reaction was estimated using the reorganization energy of the internal degrees of freedom calculated at the B3LYP level and was found to be about 6 kcal/mol. A possible influence of the interaction between RC and a neutral molecule in an encounter complex on DEE rate constant is also discussed.
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Affiliation(s)
- Vsevolod I Borovkov
- Institute of Chemical Kinetics and Combustion of SB RAS, ul. Institutskaya 3, Novosibirsk 630090, Russia.
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Saeki A, Kozawa T, Yoshida Y, Tagawa S. Adjacent Effect on Positive Charge Transfer from Radical Cation of n-Dodecane to Scavenger Studied by Picosecond Pulse Radiolysis, Statistical Model, and Monte Carlo Simulation. J Phys Chem A 2004. [DOI: 10.1021/jp036372m] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Akinori Saeki
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Takahiro Kozawa
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Yoichi Yoshida
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Seiichi Tagawa
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
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Knoesel E, Bonn M, Shan J, Wang F, Heinz TF. Conductivity of solvated electrons in hexane investigated with terahertz time-domain spectroscopy. J Chem Phys 2004; 121:394-404. [PMID: 15260559 DOI: 10.1063/1.1757442] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present investigations of the transient photoconductivity and recombination dynamics of quasifree electrons in liquid n-hexane and cyclohexane performed using terahertz time-domain spectroscopy (THz-TDS). Quasifree electrons are generated by two-photon photoionization of the liquid using a femtosecond ultraviolet pulse, and the resulting changes in the complex conductivity are probed by a THz electromagnetic pulse at a variable delay. The detection of time-domain wave forms of the THz electric field permits the direct determination of both the real and the imaginary part of the conductivity of the electrons over a wide frequency range. The change in conductivity can be described by the Drude model, thus yielding the quasifree electron density and scattering time. The electron density is found to decay on a time scale of a few hundred picoseconds, which becomes shorter with increasing excitation density. The dynamics can be described by a model that assumes nongeminate recombination between electrons and positive ions. In addition, a strong dependence of the quasifree electron density on temperature is observed, in agreement with a two-state model in which the electron may exist in either a quasifree or a bound state.
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Affiliation(s)
- Ernst Knoesel
- Department of Physics and Astronomy, Rowan University, Glassboro, New Jersey 08028, USA.
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7
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Mobility of geminate radical ions in concentrated alkane solutions as measured using electric field dependence of delayed fluorescence. Radiat Phys Chem Oxf Engl 1993 2003. [DOI: 10.1016/s0969-806x(02)00474-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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8
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SVIRIDENKO FB, STASS DV, MOLIN YUN. Study of interaction of aliphatic alcohols with primary radical cations ofn-alkanes using MARY spectroscopy. Mol Phys 2003. [DOI: 10.1080/0026897031000099943] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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9
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Fokin AA, Schreiner PR. Selective alkane transformations via radicals and radical cations: insights into the activation step from experiment and theory. Chem Rev 2002; 102:1551-94. [PMID: 11996544 DOI: 10.1021/cr000453m] [Citation(s) in RCA: 306] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Andrey A Fokin
- Department of Organic Chemistry, Kiev Polytechnic Institute, 37 Pobedy Avenue, 03056 Kiev, Ukraine.
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Shkrob IA, Liu AD, Sauer MC, Trifunac AD. High Mobility Solvent Holes in Methylcyclohexane. J Phys Chem A 2001. [DOI: 10.1021/jp003052j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- I. A. Shkrob
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - A. D. Liu
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - M. C. Sauer
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - A. D. Trifunac
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
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Shkrob IA, Sauer MC, Trifunac AD. Radiation chemistry of organic liquids: Saturated hydrocarbons. RADIATION CHEMISTRY - PRESENT STATUS AND FUTURE TRENDS 2001. [DOI: 10.1016/s0167-6881(01)80011-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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12
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Shkrob IA, Sauer MC, Trifunac AD. Reversible Reactions of Cycloalkane Solvent Holes. 2. Scavenging of cis- and trans-Decalin•+ by Benzene. J Phys Chem B 2000. [DOI: 10.1021/jp993989o] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- I. A. Shkrob
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - M. C. Sauer
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - A. D. Trifunac
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
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Shkrob IA, Sauer MC, Trifunac AD. Reversible Reactions of Cycloalkane Solvent Holes. 1. Complexation of cis- and trans-Decalin•+ with Alcohols. J Phys Chem B 2000. [DOI: 10.1021/jp993988w] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- I. A. Shkrob
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - M. C. Sauer
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - A. D. Trifunac
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
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14
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Shkrob IA, Sauer MC, Trifunac AD. Photophysics of Hole Injection in Liquid Cycloalkanes. J Phys Chem B 1999. [DOI: 10.1021/jp9900178] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- I. A. Shkrob
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - M. C. Sauer
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - A. D. Trifunac
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
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von Raumer M, Sarbach A, Haselbach E. Free ion yields in photoinduced electron transfer reactions from transient photoconductivity measurements: an overview. J Photochem Photobiol A Chem 1999. [DOI: 10.1016/s1010-6030(98)00454-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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16
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Estimation of lifetimes of solvent radical cations in liquid alkanes using the level crossing spectroscopy technique. Chem Phys Lett 1998. [DOI: 10.1016/s0009-2614(98)01099-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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17
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Shkrob IA, Liu AD, Sauer MC, Schmidt KH, Trifunac AD. Reversible Hole Trapping in Liquid Cyclohexane. J Phys Chem B 1998. [DOI: 10.1021/jp9731112] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- I. A. Shkrob
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - A. D. Liu
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - M. C. Sauer
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - K. H. Schmidt
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - A. D. Trifunac
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
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Shkrob IA, Liu AD, Sauer MC, Schmidt KH, Trifunac AD. Hole Injection and Formation of Polarons in Cycloalkane Liquids†. J Phys Chem B 1998. [DOI: 10.1021/jp973110+] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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19
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Liu AD, Shkrob IA, Sauer MC, Trifunac AD. High mobility solvent holes in cycloalkane liquids studied by a two-color laser ionization. Radiat Phys Chem Oxf Engl 1993 1998. [DOI: 10.1016/s0969-806x(97)00269-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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20
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Bühler RE, Katsumura Y. A Precursor to the Solvent Radical Cation MCH+: Pulse Radiolysis of Liquid Methylcyclohexane (MCH) at 143 K. J Phys Chem A 1998. [DOI: 10.1021/jp9720653] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- R. E. Bühler
- Laboratory for Physical Chemistry, Swiss Federal Institute of Technology, ETH-Zürich, Switzerland
| | - Y. Katsumura
- Laboratory for Physical Chemistry, Swiss Federal Institute of Technology, ETH-Zürich, Switzerland
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22
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Spin and time-resolved magnetic resonance in radiation chemistry. Recent developments and perspectives. Radiat Phys Chem Oxf Engl 1993 1997. [DOI: 10.1016/s0969-806x(97)00030-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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23
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Shkrob IA, Sauer MC, Schmidt KH, Liu AD, Yan J, Trifunac AD. Electron Transfer from Cyclohexane to Photoexcited Aromatic Ions. Generation and Kinetics of High-Mobility Solvent Holes. J Phys Chem A 1997. [DOI: 10.1021/jp9624717] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- I. A. Shkrob
- Chemistry Division , Argonne National Laboratory, Argonne, Illinois 60439
| | - M. C. Sauer
- Chemistry Division , Argonne National Laboratory, Argonne, Illinois 60439
| | - K. H. Schmidt
- Chemistry Division , Argonne National Laboratory, Argonne, Illinois 60439
| | - A. D. Liu
- Chemistry Division , Argonne National Laboratory, Argonne, Illinois 60439
| | - J. Yan
- Chemistry Division , Argonne National Laboratory, Argonne, Illinois 60439
| | - A. D. Trifunac
- Chemistry Division , Argonne National Laboratory, Argonne, Illinois 60439
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