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Miller I, Faulkner T, Raston PL. Laser Spectroscopy of Methanol Isotopologues in 4He Nanodroplets: Probing the Inertial Response around a Moderately Light Rotor. J Phys Chem A 2019; 123:1630-1636. [DOI: 10.1021/acs.jpca.8b12576] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Isaac Miller
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia 22807, United States
| | - Ty Faulkner
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia 22807, United States
| | - Paul L. Raston
- Department of Chemistry, University of Adelaide, Adelaide, SA 5005, Australia
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia 22807, United States
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2
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Briant M, Viel A, Mengesha E, Gaveau MA, Soep B, Mestdagh JM, Jamet P, Launay JM, Poisson L. Large amplitude motion within acetylene-rare gas complexes hosted in helium droplets. Phys Chem Chem Phys 2019; 21:1038-1045. [PMID: 30289418 DOI: 10.1039/c8cp04609c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Near-infrared spectroscopy of the C2H2-Ar, Kr complexes was performed in the spectral region overlapping the ν3/ν2 + ν4 + ν5 Fermi-type resonance of C2H2. The experiment was conducted along the HElium NanoDroplet Isolation (HENDI) technique in order to study the coupling dynamics between a floppy molecular system (C2H2-Ar and C2H2-Kr) and a mesoscopic quantum liquid (the droplet). Calculations were performed using a spectral element based close-coupling program and state-of-the-art 2-dimensional potential energy surfaces to determine the bound states of the C2H2-Ar and C2H2-Kr complexes and simulate the observed spectra. This furnished a quantitative basis to unravel how the superfluid and non-superfluid components of the droplet affect the rotation and the deformation dynamics of the hosted complex.
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Affiliation(s)
- Marc Briant
- LIDYL, CEA, CNRS, Université Paris-Saclay, CEA Saclay, F-91191 Gif-sur-Yvette, France.
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3
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Brice JT, Liang T, Raston PL, McCoy AB, Douberly GE. Infrared Stark and Zeeman spectroscopy of OH–CO: The entrance channel complex along the OH + CO → trans-HOCO reaction pathway. J Chem Phys 2016; 145:124310. [DOI: 10.1063/1.4963226] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Joseph T. Brice
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Tao Liang
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Paul L. Raston
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia 22807, USA
| | - Anne B. McCoy
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
| | - Gary E. Douberly
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
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4
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Schwan R, Kaufmann M, Leicht D, Schwaab G, Havenith M. Infrared spectroscopy of the ν2 band of the water monomer and small water clusters (H2O)n=2,3,4 in helium droplets. Phys Chem Chem Phys 2016; 18:24063-9. [DOI: 10.1039/c6cp04333j] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Ro-vibrational transitions of water and water clusters (H2O)n=1,2,3,4 for the ν2 bending vibration were observed and assigned to distinct structures.
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5
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Broderick BM, McCaslin L, Moradi CP, Stanton JF, Douberly GE. Reactive intermediates in 4He nanodroplets: Infrared laser Stark spectroscopy of dihydroxycarbene. J Chem Phys 2015; 142:144309. [DOI: 10.1063/1.4917421] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Affiliation(s)
| | - Laura McCaslin
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA
| | | | - John F. Stanton
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA
| | - Gary E. Douberly
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556, USA
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6
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Raston PL, Douberly GE, Jäger W. Single and double resonance spectroscopy of methanol embedded in superfluid helium nanodroplets. J Chem Phys 2014; 141:044301. [DOI: 10.1063/1.4887348] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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7
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Gomez LF, Sliter R, Skvortsov D, Hoshina H, Douberly GE, Vilesov AF. Infrared Spectra in the 3 μm Region of Ethane and Ethane Clusters in Helium Droplets. J Phys Chem A 2013; 117:13648-53. [DOI: 10.1021/jp4076542] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Luis F. Gomez
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Russell Sliter
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Dmitry Skvortsov
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Hiromichi Hoshina
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Gary E. Douberly
- Department
of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Andrey F. Vilesov
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
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8
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Barroso JZ, Perez-Delgado Y, Manzanares CE. Phase shift cavity ring down and Fourier transform infrared measurements of C-H vibrational transitions, energy levels, and intensities of (CH3)3Si-C≡C-H. J Chem Phys 2013; 139:014311. [PMID: 23822307 DOI: 10.1063/1.4812356] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Phase shift cavity ring down and Fourier transform IR techniques have been used to observe the C-H stretch fundamental and overtone absorptions of the acetylenic (Δυ = 1-5) and methyl (Δυ = 1-6) C-H bonds of trimethyl-silyl-acetylene [(CH3)3CSi≡CH] at 295 K. Harmonic frequencies ω(ν1), ω(a), and ω(s) and anharmonicities x(ν1), ω(a)x(a), ω(s)x(s) were calculated for the acetylenic, methyl out-of-plane, and methyl in-plane C-H bonds, respectively. The harmonically coupled anharmonic oscillator (HCAO) model was used to determine the overtone energy levels and assign the absorption bands to vibrational transitions of methyl C-H bonds. A hot band, assigned as υν1 + ν24 - ν24 is observed for transitions with Δυ = 1-5 in a region near the acetylenic stretch. The intensity of the hot band is reduced considerably at 240 K. The strength of a Fermi resonance between C-Ha transition (υν(a)) and the combination band ((υ-1)ν(a) + 2ν(bend)) with (υ = 3-6) was calculated using the experimental perturbed energies and relative intensities. The main bands are separated by computer deconvolution and are integrated at each level to get the experimental band strengths. For methyl absorptions, the dipole moment function is expanded as a function of two C-H stretching coordinates and the intensities are calculated in terms of the HCAO model where only the C-H modes are considered. Acetylenic intensities are derived with a one dimensional dipole moment function. The expansion coefficients are obtained from molecular orbital calculations. The intensities are calculated without using adjustable parameters and they are of the same order of magnitude of the experimental intensities for all C-H transitions.
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Affiliation(s)
- Jenny Z Barroso
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas 76706, USA
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9
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Herman M, Perry DS. Molecular spectroscopy and dynamics: a polyad-based perspective. Phys Chem Chem Phys 2013; 15:9970-93. [DOI: 10.1039/c3cp50463h] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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10
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Morrison AM, Raston PL, Douberly GE. Rotational Dynamics of the Methyl Radical in Superfluid 4He Nanodroplets. J Phys Chem A 2012; 117:11640-7. [DOI: 10.1021/jp310083j] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alexander M. Morrison
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United
States
| | - Paul L. Raston
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United
States
| | - Gary E. Douberly
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United
States
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11
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Pörtner N, Toennies JP, Vilesov AF, Stienkemeier F. Anomalous fine structures of the 000band of tetracene in large He droplets and their dependence on droplet size. Mol Phys 2012. [DOI: 10.1080/00268976.2012.679633] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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12
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Koch M, Lanzersdorfer J, Callegari C, Muenter JS, Ernst WE. Molecular Beam Magnetic Resonance in Doped Helium Nanodroplets. A Setup for Optically Detected ESR/NMR in the Presence of Unresolved Zeeman Splittings. J Phys Chem A 2009; 113:13347-56. [PMID: 19921944 DOI: 10.1021/jp9041827] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Markus Koch
- Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, A-8010 Graz, Austria/EU, and Department of Chemistry, University of Rochester, Rochester, New York 14627-0216
| | - Johannes Lanzersdorfer
- Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, A-8010 Graz, Austria/EU, and Department of Chemistry, University of Rochester, Rochester, New York 14627-0216
| | - Carlo Callegari
- Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, A-8010 Graz, Austria/EU, and Department of Chemistry, University of Rochester, Rochester, New York 14627-0216
| | - John S. Muenter
- Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, A-8010 Graz, Austria/EU, and Department of Chemistry, University of Rochester, Rochester, New York 14627-0216
| | - Wolfgang E. Ernst
- Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, A-8010 Graz, Austria/EU, and Department of Chemistry, University of Rochester, Rochester, New York 14627-0216
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13
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Lehnig R, Raston PL, Jäger W. Rotational spectroscopy of single carbonyl sulfide molecules embedded in superfluid helium nanodroplets. Faraday Discuss 2009; 142:297-309; discussion 319-34. [DOI: 10.1039/b819844f] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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14
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Szalewicz K. Interplay between theory and experiment in investigations of molecules embedded in superfluid helium nanodroplets†. INT REV PHYS CHEM 2008. [DOI: 10.1080/01442350801933485] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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15
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Lehnig R, Blinov NV, Jäger W. Evidence for an energy level substructure of molecular states in helium droplets. J Chem Phys 2007; 127:241101. [DOI: 10.1063/1.2822041] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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16
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Payne MA, Milce AP, Frost MJ, Orr BJ. Rovibrational Energy Transfer in the 4νCH Manifold of Acetylene, Viewed by IR−UV Double Resonance Spectroscopy. 5. Detailed Kinetic Model. J Phys Chem A 2007; 111:12839-53. [DOI: 10.1021/jp0767617] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mark A. Payne
- Centre for Lasers and Applications, Macquarie University, Sydney, NSW 2109, Australia
| | - Angela P. Milce
- Centre for Lasers and Applications, Macquarie University, Sydney, NSW 2109, Australia
| | - Michael J. Frost
- Centre for Lasers and Applications, Macquarie University, Sydney, NSW 2109, Australia
| | - Brian J. Orr
- Centre for Lasers and Applications, Macquarie University, Sydney, NSW 2109, Australia
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17
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Ortlieb M, Birer Ö, Letzner M, Schwaab GW, Havenith M. Observation of Rovibrational Transitions of HCl, (HCl)2, and H2O−HCl in Liquid Helium Nanodroplets. J Phys Chem A 2007; 111:12192-9. [DOI: 10.1021/jp0759980] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- M. Ortlieb
- Department of Physical Chemistry II, Ruhr-University Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany
| | - Ö. Birer
- Department of Physical Chemistry II, Ruhr-University Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany
| | - M. Letzner
- Department of Physical Chemistry II, Ruhr-University Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany
| | - G. W. Schwaab
- Department of Physical Chemistry II, Ruhr-University Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany
| | - M. Havenith
- Department of Physical Chemistry II, Ruhr-University Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany
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18
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Patkowski K, Cencek W, Jeziorska M, Jeziorski B, Szalewicz K. Accurate Pair Interaction Energies for Helium from Supermolecular Gaussian Geminal Calculations. J Phys Chem A 2007; 111:7611-23. [PMID: 17550239 DOI: 10.1021/jp071437x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nonrelativistic clamped-nuclei pair interaction energy for ground-state helium atoms has been computed for 12 interatomic separations ranging from 3.0 to 9.0 bohr. The calculations applied the supermolecular approach. The major part of the interaction energy was obtained using the Gaussian geminal implementation of the coupled-cluster theory with double excitations (CCD). Relatively small contributions from single, triple, and quadruple excitations were subsequently included employing the conventional orbital coupled-cluster method with single, double, and noniterative triple excitations [CCSD(T)] and the full configuration interaction (FCI) method. For three distances, the single-excitation contribution was taken from literature Gaussian-geminal calculations at the CCSD level. The orbital CCSD(T) and FCI calculations used very large basis sets, up to doubly augmented septuple- and sextuple-zeta size, respectively, and were followed by extrapolations to the complete basis set limits. The accuracy of the total interaction energies has been estimated to be about 3 mK or 0.03% at the minimum of the potential well. For the attractive part of the well, the relative errors remain consistently smaller than 0.03%. In the repulsive part, the accuracy is even better, except, of course, for the region where the potential goes through zero. For interatomic separations smaller than 4.0 bohr, the relative errors do not exceed 0.01%. Such uncertainties are significantly smaller than the expected values of the relativistic and diagonal Born-Oppenheimer contributions to the potential.
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Affiliation(s)
- Konrad Patkowski
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
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19
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Lehmann KK. Lorentzian line shape due to an inhomogeneous size distribution without relaxation. J Chem Phys 2007; 126:024108. [PMID: 17228944 DOI: 10.1063/1.2408416] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this paper, it is demonstrated that a Lorentzian line shape is predicted for a resonance interacting with a bath of equally spaced levels, even in the sparse, low density of states limit, if one performs an inhomogeneous average over the position of the bath states relative to the bright state. The implication for the spectroscopy of molecules in helium nanodroplets and possibly other samples with a significant size distribution is that coupling of excitations to phonons can lead to Lorentzian shaped transitions entirely from inhomogeneous broadening with no population relaxation in the sample.
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Affiliation(s)
- Kevin K Lehmann
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319, USA
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20
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Kuyanov KE, Slipchenko MN, Vilesov AF. Spectra of the ν1 and ν3 bands of water molecules in helium droplets. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2006.05.134] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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21
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Lindsay C, Douberly G, Miller R. Rotational and vibrational dynamics of H2O and HDO in helium nanodroplets. J Mol Struct 2006. [DOI: 10.1016/j.molstruc.2005.09.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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22
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Choi MY, Douberly GE, Falconer TM, Lewis WK, Lindsay CM, Merritt JM, Stiles PL, Miller RE. Infrared spectroscopy of helium nanodroplets: novel methods for physics and chemistry. INT REV PHYS CHEM 2006. [DOI: 10.1080/01442350600625092] [Citation(s) in RCA: 327] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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23
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Topic WC, Jäger W. The weakly bound He–HCCCN complex: High-resolution microwave spectra and intermolecular potential-energy surface. J Chem Phys 2005; 123:64303. [PMID: 16122304 DOI: 10.1063/1.1954767] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Rotational spectra of the weakly bound He-HCCCN and He-DCCCN van der Waals complexes were observed using a pulsed-nozzle Fourier-transform microwave spectrometer in the 7-26-GHz frequency region. Nuclear quadrupole hyperfine structures due to the 14N and D nuclei (both with nuclear-spin quantum number I = 1) were resolved and assigned. Both strong a and weaker b-type transitions were observed and the assigned transitions were used to fit the parameters of a distortable asymmetric rotor model. The dimers are floppy, near T-shaped complexes. Three intermolecular potential-energy surfaces were calculated using the coupled-cluster method with single and double excitations and noniterative inclusion of triple excitations. Bound-state rotational energy levels supported by these surfaces were determined. The quality of the potential-energy surfaces was assessed by comparing the experimental and calculated transition frequencies and also the corresponding spectroscopic parameters. Simple scaling of the surfaces improved both the transition frequencies and spectroscopic constants. Five other recently reported surfaces [O. Akin-Ojo, R. Bukowski, and K. Szalewicz, J. Chem. Phys. 119, 8379 (2003)], calculated using a variety of methods, and their agreement with spectroscopic properties of He-HCCCN are discussed.
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Affiliation(s)
- Wendy C Topic
- Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada
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25
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Abstract
The intermolecular potential surface of He-CH(3)F is investigated through ab initio calculations and microwave and millimeter-wave spectroscopies. The intermolecular potential is calculated at the fourth-order Møller-Plesset level with a large basis set including bond functions. Three minimums exist, the deepest of which is at the carbon end of the C-F axis and has a depth of 46.903 cm(-1), the second deepest is in a T-shaped position relative to the C-F axis with a depth of 44.790 cm(-1), and the shallowest is at the fluorine end of the C-F axis with a depth of 30.929 cm(-1). The barrier to internal rotation of the CH(3)F subunit about its C-F axis is very low, thus leading to essentially free internal rotation and two separate sets of bound states correlating to ortho-CH(3)F (|K| = 3n) for the ground, or A, internal rotor state upon which this study focuses, and to para-CH(3)F (|K| = 3n +/- 1) for the excited, or E, internal rotor state. Bound-state calculations of the A state performed using two different techniques show the lowest-energy state to have the helium localized in the T-shaped well with an energy of -11.460 cm(-1), while two excited configurations of the A state have the helium localized either in the well at the carbon end ("linear") with an energy of -7.468 cm(-1) or in the well at the fluorine end ("antilinear") with an energy of -4.805 cm(-1). Spectroscopic observations confirm the predicted energy-level structure of the ground and first excited states. Sixteen transitions between 12 distinct energy levels have been observed, including pure rotational transitions of both the T-shaped ground state and the linear excited state, as well as rovibrational transitions between the ground state and the linear excited state. The energy difference between the T-shaped state and the linear state is measured to be 132 374.081(16) MHz. There is significant Coriolis mixing of the ground state J(K(a)K(c)) = 2(20) and the linear J(K) = 2(0) levels which aided in the observation of the T to linear transitions. This mixing and the T to linear energy difference are sensitive probes of the relative well depths of the two lowest minimums and are well predicted by the ab initio potential. Improved agreement between experiment and theory is obtained by morphing the correlation energy of the potential. He-CH(3)F is one of just a few atom-molecule complexes for which the ground-state geometry does not coincide with the global potential minimum.
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Affiliation(s)
- Kelly J Higgins
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
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26
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Lindsay CM, Miller RE. Rotational and vibrational dynamics of ethylene in helium nanodroplets. J Chem Phys 2005; 122:104306. [PMID: 15836314 DOI: 10.1063/1.1854629] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Rotationally resolved infrared spectra are reported for the asymmetric C-H stretching fundamental bands of C(2)H(4) in helium nanodroplets, as well as two weak combination bands. The J=2 rotor levels are strongly shifted from the energies estimated from a rigid rotor calculation and can be accounted for with two centrifugal distortion constants. The excited states of the three bands with B(3u) symmetry are strongly coupled in the gas phase and exhibit lifetimes >100 ps in helium, with the upper member of the polyad exhibiting the shortest lifetime. In contrast, the nu(9) band (B(2u) symmetry) exhibits very broad, homogeneously broadened line profiles (full width at half maximum approximately 0.5 cm(-1)) corresponding to an excited state lifetime of approximately 10 ps. This short lifetime is presumed to be due to an efficient, solvent mediated vibration-to-vibration relaxation process. In addition, the absence of transitions to the 2(21) and 2(20) rotor levels in the nu(9) band suggests they form rotational resonances with the elementary modes of helium, resulting in very short excited state lifetimes of less than 2 ps.
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Affiliation(s)
- C M Lindsay
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599, USA
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27
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Scheele I, Conjusteau A, Callegari C, Schmied R, Lehmann KK, Scoles G. Near-infrared spectroscopy of ethylene and ethylene dimer in superfluid helium droplets. J Chem Phys 2005; 122:104307. [PMID: 15836315 DOI: 10.1063/1.1854630] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The nu(5)+nu(9) spectra of ethylene, C(2)H(4), and its dimer, solvated in helium nanodroplets, have been recorded in the wavelength region near 1.6 microm. The monomer transitions show homogeneous broadening of approximately 0.5 cm(-1), which is interpreted as due to an upper state vibrational relaxation lifetime of approximately 10 ps. Nearly resonant vibrational energy transfer (nu(5)+nu(9)-->2nu(5)) is proposed as the relaxation pathway. The dimer gives a single unresolved absorption feature located 4 cm(-1) to the red of the monomer band origin. The scaling of moments of inertia upon solvation in helium is 1.18 for the monomer and >2.5 for the dimer. In terms of the adiabatic following approximation, this classifies the monomer as a fast rotor and the dimer as a slow rotor.
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Affiliation(s)
- Iris Scheele
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.
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28
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Choi MY, Dong F, Miller RE. Multiple tautomers of cytosine identified and characterized by infrared laser spectroscopy in helium nanodroplets: probing structure using vibrational transition moment angles. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2005; 363:393-413. [PMID: 15664890 DOI: 10.1098/rsta.2004.1499] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Infrared laser spectroscopy in helium nanodroplets is used to identify and characterize several distinct tautomers of cytosine. The experimentally observed species correspond to the lowest-energy structures obtained from ab initio calculations, also reported here. The assignment of the infrared vibrational bands in the spectra is aided by the measurement of the corresponding vibrational transition moment angles, which are also calculated using ab initio methods. In the present study we confirm the existence of three primary tautomers and provide tentative assignments for even higher-energy forms of cytosine in helium nanodroplets.
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Affiliation(s)
- M Y Choi
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599, USA
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29
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Douberly GE, Miller RE. The isomers of HF–HCN formed in helium nanodroplets: Infrared spectroscopy and ab initio calculations. J Chem Phys 2005; 122:024306. [PMID: 15638585 DOI: 10.1063/1.1828047] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Binary complexes containing hydrogen cyanide and hydrogen fluoride are formed in helium nanodroplets, and studied using high-resolution infrared laser spectroscopy. Rotationally resolved spectra are reported for the H-F and C-H stretches of the linear HCN-HF complex, a system that has been thoroughly studied in the gas phase. We report the high-resolution spectra of the higher energy, bent HF-HCN isomer, which is also formed in helium. Stark spectra are reported for both isomers, providing dipole moments of these complexes. The experimental results are compared with ab initio calculations, also reported here. Spectra are reported for several ternary complexes, including (HCN)2-HF, HCN-(HF)2, HF-(HCN)2, and HF-HCN-HF.
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Affiliation(s)
- G E Douberly
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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Douberly GE, Merritt JM, Miller RE. IR–IR double resonance spectroscopy in helium nanodroplets: Photo-induced isomerization. Phys Chem Chem Phys 2005. [DOI: 10.1039/b417553k] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Braun A, Drabbels M. Imaging the translational dynamics of CF3 in liquid helium droplets. PHYSICAL REVIEW LETTERS 2004; 93:253401. [PMID: 15697895 DOI: 10.1103/physrevlett.93.253401] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2004] [Indexed: 05/24/2023]
Abstract
The translational dynamics of CF3 in liquid helium have been investigated by photodissociating CF3I dissolved in helium droplets consisting of several thousands of atoms. The velocity distribution of CF3 fragments that have escaped from the droplets has been determined using ion imaging techniques and is found to be considerably shifted to lower speeds with respect to the photodissociation of gas phase CF3I. The fragments furthermore show a speed dependent angular distribution that is isotropic for the slowest and approaches the gas phase distribution for the faster fragments. These distributions point to a nonthermal escape process in which, at least for the speeds relevant for the present experiment, the kinetic energy and momentum transfer from the fragments to the solvent appears to be governed by binary collisions with the individual helium atoms.
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Affiliation(s)
- Andreas Braun
- Institute of Chemical Sciences and Engineering, Swiss Federal Institute of Technology Lausanne, CH-1015 Lausanne, Switzerland
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Merritt JM, Douberly GE, Miller RE. Infrared–infrared double resonance spectroscopy of cyanoacetylene in helium nanodroplets. J Chem Phys 2004; 121:1309-16. [PMID: 15260673 DOI: 10.1063/1.1763147] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Infrared-infrared double resonance spectroscopy is used as a probe of the vibrational dynamics of cyanoacetylene in helium droplets. The nu1 C-H stretching vibration of cyanoacetylene is excited by an infrared laser and subsequent vibrational relaxation results in the evaporation of approximately 660 helium atoms from the droplet. A second probe laser is then used to excite the same C-H stretching vibration downstream of the pump, corresponding to a time delay of approximately 175 micros. The hole burned by the pump laser is narrower than the single resonance spectrum, owing to the fact that the latter is inhomogeneously broadened by the droplet size distribution. The line width of the hole is characteristic of another broadening source that depends strongly on droplet size.
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Affiliation(s)
- J M Merritt
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
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Madeja F, Havenith M, Nauta K, Miller RE, Chocholousová J, Hobza P. Polar isomer of formic acid dimers formed in helium nanodroplets. J Chem Phys 2004; 120:10554-60. [PMID: 15268082 DOI: 10.1063/1.1709942] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The infrared spectrum of formic acid dimers in helium nanodroplets has been observed corresponding to excitation of the "free" OH and CH stretches. The experimental results are consistent with a polar acyclic structure for the dimer. The formation of this structure in helium, as opposed to the much more stable cyclic isomer with two O-H...O hydrogen bonds, is attributed to the unique growth conditions that exist in helium droplets, at a temperature of 0.37 K. Theoretical calculations are also reported to aid in the interpretation of the experimental results. At long range the intermolecular interaction between the two monomers is dominated by the dipole-dipole interaction, which favors the formation of a polar dimer. By following the minimum-energy path, the calculations predict the formation of an acyclic dimer having one O-H...O and one C-H...O contact. This structure corresponds to a local minimum on the potential energy surface and differs significantly from the structure observed in the gas phase.
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Affiliation(s)
- Frank Madeja
- Department of Physical Chemistry II, Ruhr-Universität Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany
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Schmied R, Carçabal P, Dokter AM, Lonij VPA, Lehmann KK, Scoles G. UV spectra of benzene isotopomers and dimers in helium nanodroplets. J Chem Phys 2004; 121:2701-10. [PMID: 15281871 DOI: 10.1063/1.1767515] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report spectra of various benzene isotopomers and their dimers in helium nanodroplets in the region of the first Herzberg-Teller allowed vibronic transition 6(0)(1) (1)B(2u)<--(1)A(1g) (the A(0) (0) transition) at approximately 260 nm. Excitation spectra have been recorded using both beam depletion detection and laser-induced fluorescence. Unlike for many larger aromatic molecules, the monomer spectra consist of a single "zero-phonon" line, blueshifted by approximately 30 cm(-1) from the gas phase position. Rotational band simulations show that the moments of inertia of C(6)H(6) in the nanodroplets are at least six-times larger than in the gas phase. The dimer spectra present the same vibronic fine structure (though modestly compressed) as previously observed in the gas phase. The fluorescence lifetime and quantum yield of the dimer are found to be equal to those of the monomer, implying substantial inhibition of excimer formation in the dimer in helium.
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Affiliation(s)
- Roman Schmied
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.
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Polyakova E, Stolyarov D, Zhang X, Kresin V, Wittig C. Intramolecular quantum chaos in doped helium nanodroplets. Chem Phys Lett 2003. [DOI: 10.1016/s0009-2614(03)00714-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Grebenev S, Sartakov BG, Toennies JP, Vilesov AF. High-resolution infrared spectra of the OCS–H2, –HD, and –D2 van der Waals complexes in liquid helium droplets. J Chem Phys 2003. [DOI: 10.1063/1.1566945] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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Grebenev S, Sartakov B, Toennies JP, Vilesov A. Effect of the symmetry of H2 molecules on their rotations around an OCS molecule in superfluid 4He droplets. PHYSICAL REVIEW LETTERS 2002; 89:225301. [PMID: 12485078 DOI: 10.1103/physrevlett.89.225301] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2002] [Indexed: 05/24/2023]
Abstract
The infrared spectra of OCS-(H2)(n) clusters in cold (0.15 K) superfluid 4He droplets coated with 3He exhibit resolved rotational bands for each n up to n=8 para-H2 (pH(2)) or ortho-D2 (oD(2)) molecules. An analysis of the different Q-branch intensities based on the different spin symmetries of pH(2) and oD(2) indicates the formation of symmetric 5- or 6-membered rings around the linear carbonyl sulfide (OCS) chromophore. The rings of distinguishable oD(2) are found to undergo axial rotations, whereas for 6 pH(2) molecules the symmetry-allowed rotational levels lie too high to be excited at the 0.15 K droplet temperatures.
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Affiliation(s)
- Slava Grebenev
- Max-Planck-Institut für Strömungsforschung, Bunsenstrasse 10, D-37073 Göttingen, Germany
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Pörtner N, Toennies JP, Vilesov AF. The observation of large changes in the rotational constants of glyoxal in superfluid helium droplets upon electronic excitation. J Chem Phys 2002. [DOI: 10.1063/1.1502643] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Lehmann KK, Callegari C. Quantum hydrodynamic model for the enhanced moments of inertia of molecules in helium nanodroplets: Application to SF6. J Chem Phys 2002. [DOI: 10.1063/1.1486443] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Madeja F, Markwick P, Havenith M, Nauta K, Miller RE. Rotationally resolved infrared spectroscopy of h2- and d1-formic acid monomer in liquid He droplets. J Chem Phys 2002. [DOI: 10.1063/1.1432998] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Hartmann M, Lindinger A, Peter Toennies J, Vilesov AF. The phonon wings in the (S1 ← S0) spectra of tetracene, pentacene, porphin and phthalocyanine in liquid helium droplets. Phys Chem Chem Phys 2002. [DOI: 10.1039/b203249j] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Nauta K, Miller RE. The vibrational and rotational dynamics of acetylene solvated in superfluid helium nanodroplets. J Chem Phys 2001. [DOI: 10.1063/1.1412257] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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Moore DT, Ishiguro M, Miller RE. Binary complexes of HCN with H2, HD, and D2 formed in helium nanodroplets. J Chem Phys 2001. [DOI: 10.1063/1.1394744] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Nauta K, Miller R. The formation of linear and T-shaped isomers of acetylene–hydrogen cyanide complexes in helium nanodroplets. Chem Phys Lett 2001. [DOI: 10.1016/s0009-2614(01)00964-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Knözinger E, Babka E, Hallamasek D. Cage Structure and Long-Range Order in Solid Rare Gas Matrixes: A Combined FTIR and XRD Study. J Phys Chem A 2001. [DOI: 10.1021/jp012023l] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Erich Knözinger
- Institut für Physikalische und Theoretische Chemie, Technische Universität Wien Veterinärplatz 1, Trakt GA, A-1210 Wien, Austria
| | - Ewald Babka
- Institut für Physikalische und Theoretische Chemie, Technische Universität Wien Veterinärplatz 1, Trakt GA, A-1210 Wien, Austria
| | - Doris Hallamasek
- Institut für Physikalische und Theoretische Chemie, Technische Universität Wien Veterinärplatz 1, Trakt GA, A-1210 Wien, Austria
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Kunze M, Reuss J, Oomens J, Parker DH. IR excitation of ethylene molecules and clusters embedded in 4He droplets. J Chem Phys 2001. [DOI: 10.1063/1.1369659] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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