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Harries ME, Beuning CN, Johnston BL, Lovestead TM, Widegren JA. Rapid Vapor-Collection Method for Vapor Pressure Measurements of Low-Volatility Compounds. Anal Chem 2020; 92:16253-16259. [PMID: 33231433 DOI: 10.1021/acs.analchem.0c04131] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Dynamic vapor microextraction (DVME) is a new method that enables rapid vapor pressure measurements on large molecules with state-of-the-art measurement uncertainty for vapor pressures near 1 Pa. Four key features of DVME that allow for the rapid collection of vapor samples under thermodynamic conditions are (1) the use of a miniature vapor-equilibration vessel (the "saturator") to minimize the temperature gradients and internal volume, (2) the use of a capillary vapor trap to minimize the internal volume, (3) the use of helium carrier gas to minimize nonideal mixture behavior, and (4) the direct measurement of pressure inside the saturator to accurately account for overpressure caused by viscous flow. The performance of DVME was validated with vapor pressure measurements of n-eicosane (C20H42) at temperatures from 344 to 374 K. A thorough uncertainty analysis indicated a relative standard uncertainty of 2.03-2.82% for measurements in this temperature range. The measurements were compared to a reference correlation for the vapor pressures of n-alkanes; the deviation of the measurements from the correlation was ≤2.85%. The enthalpy of vaporization of n-eicosane at 359.0 K was calculated to be ΔvapH = 91.27 ± 0.28 kJ/mol compared to ΔvapH(corr) = 91.44 kJ/mol for the reference correlation. Total measurement periods as short as 15 min (3 min of thermal equilibration plus 12 min of carrier gas flow) were shown to be sufficient for high-quality vapor pressure measurements at 364 K.
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Affiliation(s)
- Megan E Harries
- Applied Chemicals and Materials Division, National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305-3337, United States
| | - Cheryle N Beuning
- Applied Chemicals and Materials Division, National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305-3337, United States
| | - Bridger L Johnston
- Applied Chemicals and Materials Division, National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305-3337, United States
| | - Tara M Lovestead
- Applied Chemicals and Materials Division, National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305-3337, United States
| | - Jason A Widegren
- Applied Chemicals and Materials Division, National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305-3337, United States
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Rogers DW, Zavitsas AA, Rogers-Bennett LK. The Gaussian G4 structure, enthalpy, and free energy of formation of trans-dimethyl-, diethyl-, dipropyl-, and dibutylcyclopentanes. J Mol Model 2019; 25:233. [DOI: 10.1007/s00894-019-4088-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Accepted: 06/04/2019] [Indexed: 11/28/2022]
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Silva VMTM, Pereira CSM, Rodrigues AE, Verevkin SP, Emel’yanenko VN, Garist IV, Gmehling J. Experimental and Theoretical Study of Chemical Equilibria in the Reactive Systems of Acetals Synthesis. Ind Eng Chem Res 2012. [DOI: 10.1021/ie301484y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Viviana M. T. M. Silva
- LSRE - Laboratory of Separation and Reaction
Engineering
- Associate Laboratory LSRE/LCM, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465
Porto, Portugal
| | - Carla S. M. Pereira
- LSRE - Laboratory of Separation and Reaction
Engineering
- Associate Laboratory LSRE/LCM, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465
Porto, Portugal
| | - Alírio E. Rodrigues
- LSRE - Laboratory of Separation and Reaction
Engineering
- Associate Laboratory LSRE/LCM, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465
Porto, Portugal
| | - Sergey P. Verevkin
- Department of Physical Chemistry, University of Rostock, Dr.-Lorenz-Weg. 1, 18059 Rostock, Germany
| | - Vladimir N. Emel’yanenko
- Department of Physical Chemistry, University of Rostock, Dr.-Lorenz-Weg. 1, 18059 Rostock, Germany
| | - Inna V. Garist
- Department of Physical Chemistry, University of Rostock, Dr.-Lorenz-Weg. 1, 18059 Rostock, Germany
| | - Jürgen Gmehling
- Technische
Chemie, Universität Oldenburg, 26111 Oldenburg, Germany
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Verevkin SP, Emel’yanenko VN, Toktonov AV, Leolko AS, Duwensee J, Kragl U, Sarge SM. Thermochemical and Ab Initio Studies of Biodiesel Fuel Surrogates: 1,2,3-Propanetriol Triacetate, 1,2-Ethanediol Diacetate, and 1,2-Ethanediol Monoacetate. Ind Eng Chem Res 2009. [DOI: 10.1021/ie900308u] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | | | | | | | - Stefan M. Sarge
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, D-38116 Braunschweig, Germany
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Tjahjono M, Widjaja E, Garland M. Combined online spectroscopic, calorimetric, and chemometric analysis: reaction enthalpy determinations in single and parallel reactions. Chemphyschem 2009; 10:1274-83. [PMID: 19360799 DOI: 10.1002/cphc.200900049] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Calorimetry and signal processing: Vibrational spectroscopies, heat-flow microcalorimetry, and multivariate analysis are combined to decouple the reaction enthalpies of parallel reactions [picture: see text]. This methodology allows the evaluation of reaction enthalpy from complex systems without recourse to conventional kinetic modeling. Simultaneous in situ/online spectroscopy and heat-flow measurements as well as multivariate analyses are performed, apparently for the first time, to determine heats of reaction for single and parallel reactions. Two different vibrational spectroscopy techniques, namely Raman and FTIR spectroscopy, are used in conjunction with flow-through TAM III microcalorimetry. With respect to the spectroscopic analysis, the reaction spectra are first analyzed to determine the pure-component spectra and the corresponding concentrations without recourse to external calibration. With respect to the calorimetric analysis, a soft modeling approach is employed to determine the heats of reaction without recourse to any conventional kinetic models. This combined approach is implemented to determine the extents of reaction as well as the corresponding heats of reaction at 298.15 K and 0.1 MPa for a) the hydrolysis of acetic anhydride (single reaction) and b) the hydrolysis of methyl paraben and ethyl paraben in alkaline solution (both single and parallel reactions). In the latter case, the heat-flow contributions from the two simultaneous reactions are successfully decoupled. Taken together, these results demonstrate proof of concept for the present approach. The newly developed methodology appears to be quite general and particularly useful for investigating complex reaction systems. This is particularly true for multiple simultaneous reactions and reactions where the detailed kinetic expressions are not available, or cannot be easily determined. The use of extents of reaction is also very helpful where there is high variability in reaction rates, that is, due to the presence of impurities, changes in catalyst activity, or concentrations, temperature, and pH.
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Affiliation(s)
- Martin Tjahjono
- Institute of Chemical and Engineering Sciences, Agency for Science, Technology and Research (A*STAR), 1 Pesek Road, Jurong Island, Singapore 627833, Singapore.
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Verevkin SP, Kozlova SA, Emel’yanenko VN, Goodrich P, Hardacre C. Thermochemistry of Ionic Liquid-Catalyzed Reactions. Experimental and Theoretical Study of Chemical Equilibria of Isomerization and Transalkylation of tert-Butylbenzenes. J Phys Chem A 2008; 112:11273-82. [DOI: 10.1021/jp806410x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sergey P. Verevkin
- Department of Physical Chemistry, University of Rostock, Hermannstrasse 14, 18051 Rostock, Germany, and QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen’s University, Belfast, U.K
| | - Svetlana A. Kozlova
- Department of Physical Chemistry, University of Rostock, Hermannstrasse 14, 18051 Rostock, Germany, and QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen’s University, Belfast, U.K
| | - Vladimir N. Emel’yanenko
- Department of Physical Chemistry, University of Rostock, Hermannstrasse 14, 18051 Rostock, Germany, and QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen’s University, Belfast, U.K
| | - Peter Goodrich
- Department of Physical Chemistry, University of Rostock, Hermannstrasse 14, 18051 Rostock, Germany, and QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen’s University, Belfast, U.K
| | - Christopher Hardacre
- Department of Physical Chemistry, University of Rostock, Hermannstrasse 14, 18051 Rostock, Germany, and QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen’s University, Belfast, U.K
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Verevkin SP, Emel’yanenko VN, Kozlova SA. Organic Carbonates: Experiment and ab Initio Calculations for Prediction of Thermochemical Properties. J Phys Chem A 2008; 112:10667-73. [DOI: 10.1021/jp8024705] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sergey P. Verevkin
- Department of Physical Chemistry, University of Rostock, Hermannstrasse 14, D-18051 Rostock, Germany
| | - Vladimir N. Emel’yanenko
- Department of Physical Chemistry, University of Rostock, Hermannstrasse 14, D-18051 Rostock, Germany
| | - Svetlana A. Kozlova
- Department of Physical Chemistry, University of Rostock, Hermannstrasse 14, D-18051 Rostock, Germany
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Pratt LM, Nguyen SC, Bui TT. A computational study of lithium ketone enolate aggregation in the gas phase and in THF solution. J Org Chem 2008; 73:6086-91. [PMID: 18646860 DOI: 10.1021/jo800528y] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The aggregation state of several lithium enolates were calculated in the gas phase and in THF solution by the B3LYP DFT and MP2 methods. The gas phase free energies of aggregate formation were underestimated by the DFT calculations, compared to those obtained by the G3MP2 method, although DFT did correctly predict the hexamer to be the major gas phase species. The DFT calculations correctly predicted the tetramer to be the major species in THF, while MP2 underestimated the stability of the tetramer relative to the dimer.
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Affiliation(s)
- Lawrence M Pratt
- Department of Chemistry, University of Science, Vietnam National University, 227 Nguyen Van Cu, District 5, Ho Chi Minh City, Vietnam.
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