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The self-associating behavior of NH3 and ND3 in liquid xenon. J Mol Struct 2016. [DOI: 10.1016/j.molstruc.2016.03.089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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De Beuckeleer LI, Herrebout WA. Self-Associating Behavior of Acetone in Liquid Krypton. J Phys Chem A 2016; 120:884-94. [PMID: 26805773 DOI: 10.1021/acs.jpca.5b10405] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Acetone molecules are inclined to self-associate through dipole-dipole interactions because of their large dipole moment. Infrared spectroscopy of compounds dissolved in liquid noble gases supported by high level ab initio calculations allows investigating the self-associating behavior and determining the thermodynamical properties. In this study, infrared spectra of various concentrations of acetone dissolved in liquid krypton are recorded at constant temperature. Overlapping monomer and dimer spectra are separated by analyzing the obtained data sets with numerical methods based on least-squares fitting. Although acetone is known to self-associate, only a few spectral features have been presented in literature before. In this study, the application of new numerical approaches succeeds in resolving overlapping spectra and allows observing isolated acetone dimer absorption bands for the complete mid infrared spectrum. By use of data sets of spectra recorded at temperatures between 134 and 142 K, the experimental standard dimerization enthalpy was determined to be -10.8 kJ mol(-1). MP2/aug-cc-pVDZ calculations predicted a stacked and planar dimer geometry of which the stacked geometry is more stable. Combining MP2 energies and single point corrections involving CCSD(T) calculations and complete basis set extrapolations based on the MP2/aug-cc-pVDZ equilibrium geometry lead to complexation energy of -28.4 kJ mol(-1) for the stacked geometry and -15.1 kJ mol(-1) for the planar geometry. The corresponding values for the complexation enthalpies in solution, obtained by combining these values with corrections for thermal and solvent influences are -13.7 and -5.8 kJ mol(-1).
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Affiliation(s)
- Liene I De Beuckeleer
- Department of Chemistry, University of Antwerp , Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Wouter A Herrebout
- Department of Chemistry, University of Antwerp , Groenenborgerlaan 171, 2020 Antwerp, Belgium
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De Beuckeleer LI, Herrebout WA. Exploring the limits of cryospectroscopy: Least-squares based approaches for analyzing the self-association of HCl. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2016; 154:89-97. [PMID: 26519915 DOI: 10.1016/j.saa.2015.10.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 10/07/2015] [Accepted: 10/19/2015] [Indexed: 06/05/2023]
Abstract
To rationalize the concentration dependent behavior observed for a large spectral data set of HCl recorded in liquid argon, least-squares based numerical methods are developed and validated. In these methods, for each wavenumber a polynomial is used to mimic the relation between monomer concentrations and measured absorbances. Least-squares fitting of higher degree polynomials tends to overfit and thus leads to compensation effects where a contribution due to one species is compensated for by a negative contribution of another. The compensation effects are corrected for by carefully analyzing, using AIC and BIC information criteria, the differences observed between consecutive fittings when the degree of the polynomial model is systematically increased, and by introducing constraints prohibiting negative absorbances to occur for the monomer or for one of the oligomers. The method developed should allow other, more complicated self-associating systems to be analyzed with a much higher accuracy than before.
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Affiliation(s)
- Liene I De Beuckeleer
- Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Wouter A Herrebout
- Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
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5
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Sawant DK, Klaassen JJ, Gounev TK, Durig JR. R0 Structural parameters, conformational, vibrational studies and ab initio calculations of cyanocyclopentane. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 151:468-479. [PMID: 26151436 DOI: 10.1016/j.saa.2015.06.116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Revised: 06/26/2015] [Accepted: 06/27/2015] [Indexed: 06/04/2023]
Abstract
The infrared and Raman spectra (3100-50 cm(-1)) of the gas, liquid or solution, and solid have been recorded of cyanocyclopentane, c-C5H9CN. Variable temperature (-60 to -100°C) studies of the infrared spectra (3100-400cm(-1)) of the sample dissolved in liquid xenon have been carried out. From these data, both the envelope-equatorial (Eq) and Ax conformers have been identified and their relative stabilities obtained. The enthalpy difference has been determined to be 55 ± 12 cm(-1) (0.66 ± 0.14 kJ/mol) with the Eq conformer the more stable form. The percentage of the Ax conformer is estimated to be 45±1% at ambient temperature. The conformational stabilities have been predicted from ab initio calculations by utilizing several different basis sets up to aug-cc-pVTZ from both MP2(full) and density functional theory calculations by the B3LYP method. Vibrational assignments have been made for the observed bands for both conformers with initial predictions by MP2(full)/6-31G(d) ab initio calculations to obtain harmonic force constants, wavenumbers, infrared intensities, Raman activities and depolarization ratios for both conformers. The r0 structural parameter values for the Eq[Ax] form are; for the heavy atom distances (Å): CN=1.160 [1.160] (3); Cα-C=1.463 [1.463] (3); Cα-Cβ, Cβ'=1.543 [1.545] (3); Cβ-Cγ, Cγ'=1.540 [1.541] (3); Cγ-Cγ'=1.552 [1.553] (3) and angles (°): ∠Cα-CN=179.0 [178.9] (5); ∠CβCα-C=113.1 [110.1] (5); ∠CβCαCβ'=103.0 [102.1] (5); ∠CαCβCγ=104.1 [104.8] (5); ∠CβCγCγ'=106.3 [106.0] (5). The results are discussed and compared to the corresponding properties of some related molecules.
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Affiliation(s)
- Dattatray K Sawant
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, MO 64110, USA
| | - Joshua J Klaassen
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, MO 64110, USA
| | - Todor K Gounev
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, MO 64110, USA
| | - James R Durig
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, MO 64110, USA.
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Darkhalil ID, Paquet C, Waqas M, Gounev TK, Durig JR. Conformational stability, r(0) structural parameters, vibrational assignments and ab initio calculations of ethyldichlorophosphine. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 136 Pt A:42-50. [PMID: 24618201 DOI: 10.1016/j.saa.2014.01.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 01/07/2014] [Accepted: 01/09/2014] [Indexed: 06/03/2023]
Abstract
Variable temperature (-60 to -100 °C) studies of ethyldichlorophosphine, CH3CH2PCl2, of the infrared spectra (4000-400 cm(-1)) dissolved in liquid xenon have been carried out. From these data, the two conformers have been identified and the enthalpy difference has been determined between the more stable trans conformer and the less stable gauche form to be 88±9 cm(-1) (1.04±0.11 kJ/mol). The percentage of abundance of the gauche conformer is estimated to be 57% at ambient temperature. The conformational stabilities have been predicted from ab initio calculations by utilizing many different basis sets up to aug-cc-pVTZ for both MP2(full) and density functional theory calculations by the B3LYP method. Vibrational assignments have been provided for both conformers which have been predicted by MP2(full)/6-31G(d) ab initio calculations to predict harmonic force fields, wavenumbers of the fundamentals, infrared intensities, Raman activities and depolarization ratios for both conformers. Estimated r0 structural parameters have been obtained from adjusted MP2(full)/6-311+G(d,p) calculations. The results are discussed and compared to the corresponding properties of some related molecules.
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Affiliation(s)
- Ikhlas D Darkhalil
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, MO 64110, USA
| | - Charles Paquet
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, MO 64110, USA
| | - Mohammad Waqas
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, MO 64110, USA
| | - Todor K Gounev
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, MO 64110, USA
| | - James R Durig
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, MO 64110, USA.
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Durig JR, Klaassen JJ, Sawant DK, Deodhar BS, Panikar SS, Gurusinghe RM, Darkhalil ID, Tubergen MJ. Microwave, structural, conformational, vibrational studies and ab initio calculations of isocyanocyclopentane. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 136 Pt A:3-15. [PMID: 24480667 DOI: 10.1016/j.saa.2013.12.078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Revised: 12/08/2013] [Accepted: 12/09/2013] [Indexed: 06/03/2023]
Abstract
The infrared and Raman spectra (3200-50 cm(-1)) of the gas, liquid or solution, and solid have been recorded of isocyanocyclopentane, c-C5H9NC. FT-microwave studies have also been carried out and 23 transitions were recorded for the envelope-axial (Ax) conformer. Variable temperature (-65 to -100 °C) studies of the infrared spectra (3200-400 cm(-1)) dissolved in liquid xenon have been carried out. From these data, both the Ax and envelope-equatorial (Eq) conformers have been identified and their relative stabilities obtained. The enthalpy difference has been determined to be 102±10 cm(-1) (1.21±0.11 kJ mol(-1)) with the Ax conformer the more stable form. The percentage of the Eq conformer is estimated to be 38±1% at ambient temperature. The conformational stabilities have been predicted from ab initio calculations by utilizing several different basis sets up to aug-cc-pVTZ from both MP2(full) and density functional theory calculations by the B3LYP method. Vibrational assignments have been made for the observed bands for both conformers with initial predictions by MP2(full)/6-31G(d) ab initio calculations to obtain harmonic force constants, wavenumbers, infrared intensities, Raman activities and depolarization ratios for both conformers. The structural parameter values for the Ax form are; for the heavy atom distances (Å): C≡N = 1.176 (3); Cα-N=1.432 (3); Cα-Cβ,Cβ'=1.534 (3); Cβ-Cγ,Cγ'=1.542 (3); Cγ-Cγ'=1.554 (3) and angles (°):∠Cα-N≡C=177.8 (5); ∠CβCα-N=110.4 (5); <CβCαCβ' = 102.9 (5); ∠CαCβCγ=103.6 (5); <CβCγCγ' = 105.9 (5). The results are discussed and compared to the corresponding properties of some related molecules.
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Affiliation(s)
- James R Durig
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, MO 64110, USA.
| | - Joshua J Klaassen
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, MO 64110, USA
| | - Dattatray K Sawant
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, MO 64110, USA
| | - Bhushan S Deodhar
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, MO 64110, USA
| | - Savitha S Panikar
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, MO 64110, USA
| | | | - Ikhlas D Darkhalil
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, MO 64110, USA
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Fishman AI, Noskov AI, Aminova RM, Skochilov RA. A study of van der Waals complexes of 1,2-dichloroethane in paraffin oil by FTIR spectroscopy and ab initio calculations. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 136 Pt A:100-106. [PMID: 24491849 DOI: 10.1016/j.saa.2014.01.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2013] [Revised: 09/16/2013] [Accepted: 01/07/2014] [Indexed: 06/03/2023]
Abstract
Weak molecular interactions of 1,2-dichloroethane dissolved in paraffin oil were investigated by FTIR spectroscopy. Occurrence of isosbestic points in the spectra along with the factor analysis showed that DCE⋯DCE dimers are formed in solutions at DCE concentrations between 7 and 15 vol.%. It was found that both trans and gauche conformers are involved in the complexation, forming a tg-dimer. From the spectra collected at 200-222 K, the complexation enthalpy was determined: -4.2±0.4 kcal mol(-1). The equilibrium geometry of tg-dimer and the vibrational frequencies were determined from the density functional calculations performed at B3LYP/6-311++G(d,p) and 6-31G(d,p) levels. The C-C bonds of the two molecules involved in tg-dimers were found to be oriented nearly perpendicular to each other. The complexation energy calculated using 6-31G(d,p) and 6-311++G(d,p) basis sets was found to be -1.59 and -1.52 kcal mol(-1), respectively.
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Affiliation(s)
- A I Fishman
- Kazan Federal University, Institute of Physics, Kremlevskaya str. 18, Kazan 420008, Russia.
| | - A I Noskov
- Kazan Federal University, Institute of Physics, Kremlevskaya str. 18, Kazan 420008, Russia
| | - R M Aminova
- Kazan Federal University, Institute of Physics, Kremlevskaya str. 18, Kazan 420008, Russia
| | - R A Skochilov
- Kazan Federal University, Institute of Physics, Kremlevskaya str. 18, Kazan 420008, Russia
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9
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Microwave, r0 structural parameters, conformational stability and vibrational assignment of cyclopropylcyanosilane. Chem Phys 2014. [DOI: 10.1016/j.chemphys.2014.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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10
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Darkhalil ID, Nagels N, Herrebout WA, van der Veken BJ, Gurusinghe RM, Tubergen MJ, Durig JR. Microwave spectra and conformational studies of ethylamine from temperature dependent Raman spectra of xenon solutions and ab initio calculations. J Mol Struct 2014. [DOI: 10.1016/j.molstruc.2014.03.073] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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11
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Mancini JS, Samanta AK, Bowman JM, Reisler H. Experiment and Theory Elucidate the Multichannel Predissociation Dynamics of the HCl Trimer: Breaking Up Is Hard To Do. J Phys Chem A 2014; 118:8402-10. [DOI: 10.1021/jp5015753] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- John S. Mancini
- Department
of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, United States
| | - Amit K. Samanta
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Joel M. Bowman
- Department
of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, United States
| | - Hanna Reisler
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
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12
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Bulanin CKCМ, Bulychev VP, Herrebout W, Schepkin DN. IR spectroscopic study of the HCl···O3 molecular complex in liquid argon. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2014; 117:713-717. [PMID: 24140459 DOI: 10.1016/j.saa.2013.08.119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Accepted: 08/30/2013] [Indexed: 06/02/2023]
Abstract
Infrared spectra are reported of ozone and HCl dissolved in liquid argon (86-134 K) at concentrations varying from 5×10(-5) to 9×10(-6) M for HCl, and from 1×10(-3) to 5×10(-5) M for ozone. At low concentrations of O3 and of HCl, no spectral features due to O3-HCl complex were found. At higher concentrations (1×10(-3) of ozone vs 5×10(-5)-9×10(-6) of HCl), a new band near 2840 cm(-1) due to the HCl···O3 complex was observed. FWHM of νHCl of the complex is 8 cm(-1). From the temperature dependence of the absorption band intensity, the enthalpy of the complex formation was estimated, ΔH°=4.7±0.4 kJ mole(-1). The optimized geometry of the cis-HCl···O3 complex and a value of 6.3 kJ mole(-1) for its binding energy were determined by ab initio calculations.
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13
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Mancini JS, Bowman JM. On-the-fly ab intito calculations of anharmonic vibrational frequencies: Local-monomer theory and application to HCl clusters. J Chem Phys 2013; 139:164115. [DOI: 10.1063/1.4826351] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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14
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Klaassen JJ, Darkhalil ID, Deodhar BS, Gounev TK, Gurusinghe RM, Tubergen MJ, Groner P, Durig JR. Microwave and Infrared Spectra, Adjusted r0 Structural Parameters, Conformational Stabilities, Vibrational Assignments, and Theoretical Calculations of Cyclobutylcarboxylic Acid Chloride. J Phys Chem A 2013; 117:6508-24. [DOI: 10.1021/jp404510n] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Joshua J. Klaassen
- Department
of Chemistry, University of Missouri−Kansas City, Kansas City,
Missouri 64110, United States
| | - Ikhlas D. Darkhalil
- Department
of Chemistry, University of Missouri−Kansas City, Kansas City,
Missouri 64110, United States
| | - Bhushan S. Deodhar
- Department
of Chemistry, University of Missouri−Kansas City, Kansas City,
Missouri 64110, United States
| | - Todor K. Gounev
- Department
of Chemistry, University of Missouri−Kansas City, Kansas City,
Missouri 64110, United States
| | - Ranil M. Gurusinghe
- Department of Chemistry, Kent State University, Kent, Ohio 44242, United States
| | - Michael J. Tubergen
- Department of Chemistry, Kent State University, Kent, Ohio 44242, United States
| | - Peter Groner
- Department
of Chemistry, University of Missouri−Kansas City, Kansas City,
Missouri 64110, United States
| | - James R. Durig
- Department
of Chemistry, University of Missouri−Kansas City, Kansas City,
Missouri 64110, United States
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Conformational and structural studies of ethynylcyclopentane from temperature dependent Raman spectra of xenon solutions, infrared spectra, and ab initio calculations. J Mol Struct 2013. [DOI: 10.1016/j.molstruc.2012.12.046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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16
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Panikar SS, Guirgis GA, Eddens MT, Dukes HW, Conrad AR, Tubergen MJ, Gounev TK, Durig JR. Microwave, infrared and Raman spectra, adjusted r0 structural parameters, conformational stability, and vibrational assignment of cyclopropylfluorosilane. Chem Phys 2013. [DOI: 10.1016/j.chemphys.2012.12.036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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17
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Klaassen JJ, Panikar SS, Guirgis GA, Dukes HW, Wyatt JK, Durig JR. Conformational and structural studies of cyclobutylsilane from temperature dependent infrared spectra of xenon solutions and ab initio calculations. J Mol Struct 2013. [DOI: 10.1016/j.molstruc.2012.09.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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18
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Durig JR, Darkhalil ID, Klaassen JJ, Nagels N, Herrebout WA, van der Veken BJ. Conformational and structural studies of 2,2,2 trifluoroethylamine from temperature dependent Raman spectra of xenon solutions and ab initio calculations. J Mol Struct 2013. [DOI: 10.1016/j.molstruc.2012.10.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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19
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Guirgis GA, Klaassen JJ, Deodhar BS, Sawant DK, Panikar SS, Dukes HW, Wyatt JK, Durig JR. Structure and conformation studies from temperature dependent infrared spectra of xenon solutions and ab initio calculations of cyclobutylgermane. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2012; 99:266-278. [PMID: 23085284 DOI: 10.1016/j.saa.2012.09.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 09/09/2012] [Accepted: 09/16/2012] [Indexed: 06/01/2023]
Abstract
The infrared spectra (3500-220 cm(-1)) of cyclobutylgermane, c-C(4)H(7)GeH(3) have been recorded of the gas. Also variable temperature (-65 to -100 °C) studies of the infrared spectra (3500-400 cm(-1)) of the sample dissolved in liquid xenon were recorded and both the equatorial and axial conformers were identified. The enthalpy difference has been determined from 10 band pairs 8 temperatures to give 112 ± 11 cm(-1) (1.34 ± 0.13 kJ mol(-1)) with the equatorial conformer the more stable form. The percentage of the axial conformer present at ambient temperature is estimated to be 37 ± 1%. From ab initio calculations conformational stabilities have been predicted from both MP2(full) and density functional theory calculations from a variety of basic sets. The r(0) structure parameters have been obtained for both conformers from the previously reported rotational constants from the three isotopologues. The determined heavy atom distances for the equatorial [axial] form are (Å) Ge-C(α)=1.952(3) [1.950(3)], [Formula: see text] , [Formula: see text] [1.551(3)] and angles in degrees (°) ∠GeC(α)C(β)=118.6(5) [113.4(5)], [Formula: see text] , ∠C(α)C(β)C(γ)=87.8(5) [88.8(5)], [Formula: see text] and a puckering angle of 29.1(5) [25.1(5)]. Data from ab initio calculations were used to predict vibrational harmonic force constants, fundamental wavenumbers, infrared intensities, Raman activities and depolarization ratios for both conformers. The results are compared to the corresponding properties of some related molecules.
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Affiliation(s)
- Gamil A Guirgis
- Department of Chemistry and Biochemistry, College of Charleston, Charleston, SC 29424, USA
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20
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Durig JR, Klaassen JJ, Deodhar BS, Gounev TK, Conrad AR, Tubergen MJ. Microwave, infrared, and Raman spectra, r0 structural parameters, conformational stability, and vibrational assignment of allyl thiol. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2012; 87:214-227. [PMID: 22178242 DOI: 10.1016/j.saa.2011.11.041] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2011] [Accepted: 11/14/2011] [Indexed: 05/31/2023]
Abstract
FT-microwave spectrum of allyl thiol, H(2)CCHCH(2)SH, has been recorded, and 19 transitions have been assigned for the most abundant isotopologue of Gg conformer, and the rotational constants have been determined; A=20,041.439 (4), B=2795.830 (1), C=2701.084 (1). From the determined microwave rotational constants and ab initio MP2(full)/6-311+G(d,p) predicted structural values, adjusted r(0) parameters are reported with distances (Å): rCC=1.343 (3), rC-C=1.496 (3), rC-S=1.827 (3) and angles (°) ∠CCC=123.4 (5), ∠CCS=112.5 (5), and τC(γ)C(β)C(α)S=118.7 (5). Variable temperature (-55 to -100°C) infrared spectra (3600-400cm(-1)) were recorded of allyl thiol in liquid xenon and the Gg conformer was determined to be the most stable form. The enthalpy differences relative to the Gg form are for Cg 120±9cm(-1) (1.44±0.11kJ/mol), for Gg' 337±34cm(-1) (4.03±0.41kJ/mol), and for Gt 360±36cm(-1) (4.31±0.43kJ/mol). The relative amounts present at ambient temperature are Gg 52±1%, Cg 29±1%, Gg' 10±1%, and Gt 9±1%. The conformational stabilities have been predicted from ab initio calculations with many basis sets up to aug-cc-pVTZ and the predicted stabilities are in agreement with the experimentally determined order. Vibrational assignments are reported with support by ab initio predictions and results are discussed.
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Affiliation(s)
- James R Durig
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, MO 64110, USA.
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21
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Conformational and structural studies of isopropylamine from temperature dependent Raman spectra of xenon solutions and ab initio calculations. J Mol Struct 2012. [DOI: 10.1016/j.molstruc.2011.07.026] [Citation(s) in RCA: 7] [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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Ganguly A, Klaassen JJ, Guirgis GA, Gounev TK, Durig JR. Conformational stability, r0 structural parameters, and vibrational assignments of mono-substituted cyclobutanes: fluorocyclobutane. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 79:831-840. [PMID: 21030298 DOI: 10.1016/j.saa.2010.08.082] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Revised: 07/11/2010] [Accepted: 08/26/2010] [Indexed: 05/30/2023]
Abstract
Variable temperature (-55 to -100°C) studies of the infrared spectra (3500-400 cm(-1)) of fluorocyclobutane, c-C(4)H(7)F, dissolved in liquid xenon have been carried out as well as the infrared spectra of the gas. By utilizing eight pairs of conformers at 10 different temperatures, the enthalpy difference between the more stable equatorial conformer and the axial form has been determined to be 496±40 cm(-1) (5.93±0.48 kJ/mol). The percentage of the axial conformer present at ambient temperature is estimated to be 8±1%. The ab initio MP2(full) average predicted energy difference from a variety of basis sets is 732±47 cm(-1) (9.04±0.44 kJ/mol) and the average value of 602±20 cm(-1) from density functional theory predictions by the B3LYP method are significantly larger than the experimentally determined enthalpy value. By utilizing previously reported microwave rotational constants for the equatorial and axial conformers combined with ab initio MP2(full)/6-311+G(d,p) predicted structural values, adjusted r(0) parameters have been obtained. The determined heavy atom structural parameters for the equatorial [axial] conformer are: distances (Å) C-F=1.383(3) [1.407(3)], C(α)-C(β)=1.543(3) [1.546(3)], C(β)-C(γ)=1.554(3) [1.554(3)] and angles (°) ∠C(α)C(β)C(γ)=85.0(5) [89.2(5)], ∠C(β)C(α)C(β)=89.3(5) [89.2(5)], ∠F-(C(β)C(α)C(β))=117.4(5) [109.2(5)] and a puckering angle of 37.4(5) [20.7(5)]. The conformational stabilities, harmonic force fields, infrared intensities, Raman activities, depolarization ratios and vibrational frequencies have been obtained for both conformers from MP2(full)/6-31G(d) ab initio calculations and compared to experimental values where available. The results are discussed and compared to the corresponding properties of some other monosubstituted cyclobutanes with halogen and pseudo-halogen substituents.
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Affiliation(s)
- Arindam Ganguly
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, MO 64110, USA
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Durig JR, El-Defrawy AM, Ganguly A, Panikar SS, Soliman MS. Conformational Stability from Variable-Temperature Infrared Spectra of Xenon Solutions, r0 Structural Parameters, and Vibrational Assignment of Pyrrolidine. J Phys Chem A 2011; 115:7473-83. [DOI: 10.1021/jp200692t] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- James R. Durig
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, Missouri 64110, United States
| | - Ahmed M. El-Defrawy
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, Missouri 64110, United States
| | - Arindam Ganguly
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, Missouri 64110, United States
| | - Savitha S. Panikar
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, Missouri 64110, United States
| | - Mamdouh S. Soliman
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, Missouri 64110, United States
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Dom JJJ, van der Veken BJ, Michielsen B, Jacobs S, Xue Z, Hesse S, Loritz HM, Suhm MA, Herrebout WA. On the weakly C-H···π hydrogen bonded complexes of sevoflurane and benzene. Phys Chem Chem Phys 2011; 13:14142-52. [PMID: 21666925 DOI: 10.1039/c1cp20693a] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A vibrational assignment of the anaesthetic sevoflurane, (CF(3))(2)CHOCH(2)F, is proposed and its interaction with the aromatic model compound benzene is studied using vibrational spectroscopy of supersonic jet expansions and of cryosolutions in liquid xenon. Ab initio calculations, at the MP2/cc-pVDZ and MP2/aug-cc-pVDZ levels, predict two isomers for the 1 : 1 complex, one in which the near-cis, gauche conformer of sevoflurane is hydrogen bonded through its isopropyl-hydrogen atom, the other in which the same conformer is bonded through a bifurcated hydrogen bond with the fluoromethyl hydrogen atoms. From the experiments it is shown that the two isomers are formed, however with a strong population dominance of the isopropyl-bonded species, both in the jet and liquid phase spectra. The experimental complexation enthalpy in liquid xenon, ΔH(o)(LXe), of this species equals -10.9(2) kJ mol(-1), as derived from the temperature dependent behaviour of the cryosolution spectra. Theoretical complexation enthalpies in liquid xenon were obtained by combining the complete basis set extrapolated complexation energies at the MP2/aug-cc-pVXZ (X = D,T) level with corrections derived from statistical thermodynamics and Monte Carlo Free Energy Perturbation calculations, resulting in a complexation enthalpy of -11.2(3) kJ mol(-1) for the isopropyl-bonded complex, in very good agreement with the experimental value, and of -11.4(4) kJ mol(-1), for the fluoromethyl-bonded complex. The Monte Carlo calculations show that the solvation entropy of the isopropyl-bonded species is considerably higher than that of the fluoromethyl-bonded complex, which assists in explaining its dominance in the liquid phase spectra.
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Affiliation(s)
- Johan J J Dom
- Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
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25
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Conformational and structural studies of 2,2-difluoroethylamine from temperature dependent infrared spectra of xenon solution and ab initio calculations. J Mol Struct 2011. [DOI: 10.1016/j.molstruc.2010.10.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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26
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Durig JR, Zhou SX, Guirgis GA, Wurrey CJ. Conformational stability from variable temperature infrared spectra of xenon solutions, r0 structural parameters, and ab initio calculations of cyclopropylisocyanate. J Phys Chem A 2011; 115:2297-307. [PMID: 21366209 DOI: 10.1021/jp108879u] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Infrared spectra (4000 to 400 cm(-1)) of the gas and variable temperature xenon solutions, and the Raman spectrum of the liquid have been recorded for cyclopropylisocyanate. The enthalpy difference has been determined to be 77 ± 8 cm(-1) (0.92 ± 0.10 kJ/mol) with the trans form more stable than the cis conformer with 59 ± 2% present at ambient temperature. By utilizing three rotational constants for each conformer, combined with structural parameters predicted from MP2(full)/6-311+G(d,p) calculations, the adjusted r(0) parameters have been obtained. Heavy atom structural parameters for the trans [cis] conformers are the following: distances (Å) (C-C(2,3)) = 1.509(3) [1.509(3)], (C(2)-C(3)) = 1.523(3) [1.521(3)], (C-N) = 1.412(3) [1.411(3)], (N═C) =1.214(3) [1.212(3)], (C═O) = 1.163(3) [1.164(3)]; angles (°) ∠CCN = 116.7(5) [120.1(5)], ∠CNC = 136.3(5) [137.6(5)]. The centrifugal distortion constants have been predicted from ab initio and DFT calculations and are compared to the experimentally determined values.
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Affiliation(s)
- James R Durig
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, Missouri 64110, USA.
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27
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The r0 structural parameters, conformational stability, barriers to internal rotation, and vibrational assignments for trans and gauche ethanol. J Mol Struct 2011. [DOI: 10.1016/j.molstruc.2010.10.043] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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28
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Hauchecorne D, van der Veken BJ, Moiana A, Herrebout WA. The C–Cl⋯N halogen bond, the weaker relative of the C–I and C–Br⋯N halogen bonds, finally characterized in solution. Chem Phys 2010. [DOI: 10.1016/j.chemphys.2010.06.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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29
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Durig JR, Ward RM, Nelson KG, Gounev TK. Conformational stability from variable temperature infrared spectra of xenon solution, r0 structural parameters, and vibrational assignment of fluorocyclohexane. J Mol Struct 2010. [DOI: 10.1016/j.molstruc.2010.01.058] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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30
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Durig JR, Ward RM, Conrad AR, Tubergen MJ, Nelson KG, Gounev TK. Microwave, infrared, and Raman spectra, r0 structural parameters, conformational stability, and vibrational assignment of ethynylcyclohexane. J Mol Struct 2010. [DOI: 10.1016/j.molstruc.2010.03.040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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31
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Durig JR, Zhou SX, Zheng C, Durig DT. Conformational stability, structural parameters and vibrational assignment from variable temperature infrared spectra of xenon and krypton solutions and ab initio calculations of ethylisocyanate. J Mol Struct 2010. [DOI: 10.1016/j.molstruc.2010.02.066] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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32
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Durig JR, Ganguly A, Zheng C, Gurigis G, Herrebout W, van der Veken B, Gounev TK. Conformational and structural studies of 2-fluoroethylamine from temperature dependent FT-IR spectra of krypton and xenon solutions and ab initio calculations. J Mol Struct 2010. [DOI: 10.1016/j.molstruc.2010.01.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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33
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Durig JR, Panikar SS, Guirgis GA, Gounev TK, Klæboe P, Horn A, Nielsen CJ, Peebles RA, Peebles SA, Liberatore RJ. Conformational stability, r0 structural parameters, barriers to internal rotation, vibrational assignments and ab initio calculations of c-C3H5GeH2CH3. J Mol Struct 2010. [DOI: 10.1016/j.molstruc.2010.01.042] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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34
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Michielsen B, Dom JJJ, Veken BJVD, Hesse S, Xue Z, Suhm MA, Herrebout WA. The complexes of halothane with benzene: the temperature dependent direction of the complexation shift of the aliphatic C–H stretching. Phys Chem Chem Phys 2010; 12:14034-44. [DOI: 10.1039/c0cp00771d] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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35
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The r0 structural parameters, conformational stability, and vibrational assignment of equatorial and axial bromocyclobutane. J Mol Struct 2009. [DOI: 10.1016/j.molstruc.2009.06.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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36
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Hauchecorne D, Szostak R, Herrebout WA, van der Veken BJ. CX⋅⋅⋅O Halogen Bonding: Interactions of Trifluoromethyl Halides with Dimethyl Ether. Chemphyschem 2009; 10:2105-15. [DOI: 10.1002/cphc.200900125] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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37
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Durig JR, Ganguly A, Klaassen JJ, Guirgis GA. The r0 structural parameters, conformational stability, and vibrational assignment of equatorial and axial cyanocyclobutane. J Mol Struct 2009. [DOI: 10.1016/j.molstruc.2009.01.044] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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38
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Durig JR, Panikar SS, Guirgis GA, Gounev TK, Ward RM, Peebles RA, Peebles SA, Liberatore RJ, Bell S, Wurrey CJ. Conformational stability, r0 structural parameters, barriers to internal rotation, vibrational spectra and ab initio calculations of c-C3H5SiH2CH3. J Mol Struct 2009. [DOI: 10.1016/j.molstruc.2008.12.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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39
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Durig JR, Ganguly A, Defrawy AME, Zheng C, Badawi HM, Herrebout W, Veken BVD, Guirgis GA, Gounev TK. Conformational stability of allyl alcohol from temperature dependent infrared spectra of rare gas solutions, ab initio calculations, r0 structural parameters, and vibrational assignment. J Mol Struct 2009. [DOI: 10.1016/j.molstruc.2009.01.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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40
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Microwave spectra, r0 structural parameters, and conformational stability from xenon solutions of silylcyclohexane. J Mol Struct 2009. [DOI: 10.1016/j.molstruc.2009.01.046] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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41
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Nashed YE, Qtaitat MA, Zheng C, Zhou X, Guirgis GA, Sullivan JF, Durig JR. Conformational stability from rare gas solutions, r0 structural parameters, barriers to internal rotation, and ab initio calculations for vinyl silyl fluoride. J Phys Chem A 2009; 113:1653-62. [PMID: 19199671 DOI: 10.1021/jp8076547] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The Raman (3300-10 cm(-1)) and infrared (3300-40 cm(-1)) spectra of gaseous and solid vinyl silyl fluoride, CH(2)=CHSiH(2)F, have been recorded. Raman spectrum of the liquid has also been recorded and depolarization values obtained. Variable-temperature studies of the infrared spectra of the sample dissolved in liquid krypton (-110 to -150 degrees C) and liquid xenon (-60 to -100 degrees C) have been carried out. From these studies, the enthalpy difference has been determined to be 76 +/- 7 cm(-1) (0.91 +/- 0.08 kJ/mol) from the krypton solutions and 69 +/- 7 cm(-1) (0.82 +/- 0.08 kJ/mol) from the xenon solutions, with the gauche conformer the more stable form. From the far-infrared spectrum of the gas, the asymmetric torsional fundamentals for the cis and gauche conformers have been observed at 102.34 and 86.56 cm(-1), respectively, with each having several "hot bands" falling to lower frequencies. From these frequencies along with the experimentally determined conformational enthalpy difference, as well as the gauche skeletal dihedral angle, the potential function governing the conformational interchange has been determined with the following Fourier cosine potential coefficients: V(1) = -80 +/- 11, V(2) = -42 +/- 15, V(3) = 622 +/- 5, V(4) = 34 +/- 5, and V(6) = -31 +/- 2 cm(-1). The gauche-to-cis and gauche-to-gauche barriers are 664 cm(-1) (7.94 kJ/mol) and 608 cm(-1) (7.27 kJ/mol), respectively. Complete vibrational assignments are provided for both conformers. In addition, equilibrium geometries and electronic energies have been determined for both rotamers from ab initio calculations using restricted Hartree-Fock and Møller-Plesset perturbation method to the second order (MP2), as well as density functional theory by the B3LYP methods, employing a number of basis sets up to 6-311+G(2df,2pd). All levels of calculation predict the gauche conformer to be the more stable form. By systematically adjusting the ab initio predicted structural values to fit the previously reported microwave rotational constants, adjusted r(0) parameters have been obtained for both conformers. These values are compared to those for the corresponding chloride and methyl compounds. The spectroscopic and theoretical results are discussed and compared to the corresponding quantities for some similar molecules.
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Affiliation(s)
- Yasser E Nashed
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, Missouri 64110, USA
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42
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Durig JR, El Defrawy AM, Ward RM, Guirgis GA, Gounev TK. Conformational stability of bromocyclohexane from temperature dependent FT-IR spectra of xenon solutions, r0 structural parameters and vibrational assignment. J Mol Struct 2009. [DOI: 10.1016/j.molstruc.2008.07.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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43
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Durig JR, Ganguly A, El Defrawy AM, Gounev TK, Guirgis GA. Conformational stability of cyclobutanol from temperature dependent infrared spectra of xenon solutions, r0 structural parameters, ab initio calculations and vibrational assignment. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2008; 71:1379-1389. [PMID: 18602334 DOI: 10.1016/j.saa.2008.04.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2008] [Revised: 04/18/2008] [Accepted: 04/18/2008] [Indexed: 05/26/2023]
Abstract
Variable temperature (-55 to -100 degrees C) studies of the infrared spectra (4000-400 cm(-1)) of cyclobutanol, c-C4H7OH dissolved in liquid xenon have been carried out. The infrared spectrum (4000-100 cm(-1)) of the gas has also been recorded. From these data two of the four possible stable conformers have been confidently identified and their order of stabilities has been experimentally determined where the first indicator is for the position of attachment of the hydroxyl group on the bent cyclobutyl ring (Eq=equatorial or Ax=axial) and the second one (t=trans, g=gauche) is the relative position of the hydroxyl rotor, i.e. rotation around the ring C-O bond. The enthalpy difference between the most stable Eq-t conformer and the second most stable rotamer, Eq-g, has been determined to be 200+/-50 cm(-1) (2.39+/-0.60 kJ/mol). This experimentally determined order is consistent with the order of stability predicted by ab initio calculations Eq-t>Eq-g>Ax-g>Ax-t. Evidence was obtained for the third conformer Ax-g which is predicted by ab initio calculations to be less stable by more than 650cm(-1) than the Eq-t form. The percentage of each conformer at ambient temperature is estimated to be Eq-t (50%), Eq-g (47%) and Ax-g (3%). The conformational stabilities, harmonic force fields, infrared intensities, Raman activities, depolarization ratios and vibrational frequencies have been obtained for all of the conformers from MP2(full)/6-31G(d) ab initio calculations. The optimized geometries and conformational stabilities have been obtained from ab initio calculations utilizing several different basis sets up to MP2(full)/aug-cc-pVTZ and from density functional theory calculations by the B3LYP method. By utilizing previously reported microwave rotational constants for the Eq-t conformer combined with ab initio MP2(full)/6-311+G(d,p) predicted structural values, adjusted r0 parameters have been obtained. The determined heavy atom structural parameters for the Eq-t conformer are: the distances C1-C4=1.547(5) angstroms, C4-C6=1.552(5)angstroms, C-O=1.416(5) angstroms and angles angleC6C4C1=86.6(5) degrees , angleC4C1C5=88.9(5) degrees and angleC6C5C1C4=22.8(5) degrees . The results are discussed and compared to the corresponding properties of some similar molecules.
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Affiliation(s)
- James R Durig
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, MO 64110, USA.
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44
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Rutkowski KS, Herrebout WA, Melikova SM, van der Veken BJ, Koll A. A cryosolution FTIR and ab initio study of the blue shifting C–H···F hydrogen bonded complexes F2ClCH·FCD3 and Cl2FCH·FCD3. Chem Phys 2008. [DOI: 10.1016/j.chemphys.2008.09.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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45
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The r 0 structural parameters of equatorial and axial chlorocyclobutane, conformational stability from temperature dependent infrared spectra of xenon solutions, and vibrational assignments. Struct Chem 2008. [DOI: 10.1007/s11224-008-9378-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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46
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Michielsen B, Herrebout WA, van der Veken BJ. CH bonds with a Positive Dipole Gradient Can Form Blue-Shifting Hydrogen Bonds: The Complex of Halothane with Methyl Fluoride. Chemphyschem 2008; 9:1693-701. [DOI: 10.1002/cphc.200800263] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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47
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Conformational stability of chlorocyclohexane from temperature-dependent FT-IR spectra of xenon solutions, r 0 structural parameters, and vibrational assignment. Struct Chem 2008. [DOI: 10.1007/s11224-008-9328-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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48
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Guirgis GA, Yu Z, Zheng C, Zhou SX, Durig JR. Conformational stability from variable temperature FT-IR spectra of krypton solutions, r0 structural parameters, vibrational assignment, and ab initio calculations of 4-fluoro-1-butene. J Phys Chem A 2008; 112:2268-81. [PMID: 18298100 DOI: 10.1021/jp0748213] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Variable temperature (-115 to -155 degrees C) studies of the infrared spectra (3200-400 cm-1) of 4-fluoro-1-butene, CH2=CHCH2CH2F, dissolved in liquid krypton have been carried out. The infrared spectra of the gas and solid as well as the Raman spectra of the gas, liquid, and solid have also been recorded from 3200 to 100 cm-1. From these data, an enthalpy difference of 72 +/- 5 cm-1 (0.86 +/- 0.06 kJ x mol-1) has been determined between the most stable skew-gauche II conformer (the first designation refers to the position of the CH2F group relative to the double bond, and the second designation refers to the relative positions of the fluorine atom to the C-C(=C) bond) and the second most stable skew-trans form. The third most stable conformer is the skew-gauche I with an enthalpy difference of 100 +/- 7 cm-1 (1.20 +/- 0.08 kJ x mol-1) to the most stable form. Larger enthalpy values of 251 +/- 12 cm-1 (3.00 +/- 0.14 kJ x mol-1) and 268 +/- 17 cm-1 (3.21 +/- 0.20 kJ x mol-1) were obtained for the cis-trans and cis-gauche conformers, respectively. From these data and the relative statistical weights of one for the cis-trans conformer and two for all other forms, the following conformer percentages are calculated at 298 K: 36.4 +/- 0.9% skew-gauche II, 25.7 +/- 0.1% skew-trans, 22.5 +/- 0.2% skew-gauche I, 10.0 +/- 0.6% cis-gauche, and 5.4 +/- 0.2% cis-trans. The potential surface describing the conformational interchange has been analyzed and the corresponding two-dimensional Fourier coefficients were obtained. Nearly complete vibrational assignments for the three most stable conformers are proposed and some fundamentals for the cis-trans and the cis-gauche conformers have been identified. The structural parameters, dipole moments, conformational stability, vibrational frequencies, infrared, and Raman intensities have been predicted from ab initio calculations and compared to the experimental values when applicable. The adjusted r0 structural parameters have been determined by combining the ab initio predicted parameters with previously reported rotational constants from the microwave data. These experimental and theoretical results are compared to the corresponding quantities of some similar molecules.
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Affiliation(s)
- Gamil A Guirgis
- Department of Chemistry & Biochemistry, College of Charleston, Charleston, South Carolina 29424, USA
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49
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Skvortsov D, Choi MY, Vilesov AF. Study of HCl Clusters in Helium Nanodroplets: Experiments and ab Initio Calculations as Stepping Stones from Gas Phase to Bulk. J Phys Chem A 2007; 111:12711-6. [DOI: 10.1021/jp076123o] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dmitry Skvortsov
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, and Department of Chemistry and Research Institute of Natural Sciences, Gyeongsang National University, Jinju, 660-701, South Korea
| | - Myong Yong Choi
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, and Department of Chemistry and Research Institute of Natural Sciences, Gyeongsang National University, Jinju, 660-701, South Korea
| | - Andrey F. Vilesov
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, and Department of Chemistry and Research Institute of Natural Sciences, Gyeongsang National University, Jinju, 660-701, South Korea
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50
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Michielsen B, Herrebout WA, van der Veken BJ. Intermolecular Interactions between Halothane and Dimethyl Ether: A Cryosolution Infrared and Ab Initio Study. Chemphyschem 2007; 8:1188-98. [PMID: 17492702 DOI: 10.1002/cphc.200700126] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The complex of halothane (CHClBrCF(3)) and dimethyl ether has been investigated experimentally in solutions of liquid krypton using infrared spectroscopy and theoretically using ab initio calculations at the MP2/6-311++G(d,p) level. The formation of a 1:1 complex was experimentally detected. The most stable ab initio geometry found is the one in which the C--H bond of halothane interacts with the oxygen atom of dimethyl ether. The complexes in which the chlorine or the bromine atom of halothane interacts with the oxygen atom of the ether were found to be local energy minima and were less stable by 14.5 and 9.3 kJ mol(-1), respectively, than the global minimum. The formation of a single complex species was observed in the infrared spectra; the standard complexation enthalpy of this complex was determined to be -12.3(8) kJ mol(-1). Analysis of the observed complexation shifts supports the identification of the complex as the hydrogen-bonded species. The C--H stretching vibration of halothane was found to show a redshift upon complexation of 19(2) cm(-1). The infrared intensity ratios epsilon(complex)/epsilon(monomer) for the fundamental and its first overtone were measured to be 6.5(1) and 0.31(1). The frequency shift was analyzed using Morokuma-type analysis, and the infrared intensity ratios were rationalized using a model including the mechanical and electric anharmonicity of the C--H stretching fundamental.
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Affiliation(s)
- Bart Michielsen
- Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, B2020 Antwerp, Belgium
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