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Barclay AJ, McKellar ARW, Moazzen-Ahmadi N, Dawes R, Wang XG, Carrington T. Infrared spectrum and intermolecular potential energy surface of the CO–O2 dimer. Phys Chem Chem Phys 2018; 20:14431-14440. [DOI: 10.1039/c8cp02282h] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The spectrum of the weakly-bound radical complex CO–O2 is studied for the first time.
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Affiliation(s)
- A. J. Barclay
- Department of Physics and Astronomy
- University of Calgary
- Calgary
- Canada
| | | | - N. Moazzen-Ahmadi
- Department of Physics and Astronomy
- University of Calgary
- Calgary
- Canada
| | - Richard Dawes
- Department of Chemistry
- Missouri University of Science and Technology
- Rolla
- USA
| | - Xiao-Gang Wang
- Chemistry Department
- Queen's University
- Ontario K7L 3N6
- Canada
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2
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Herman M, Földes T, Didriche K, Lauzin C, Vanfleteren T. Overtone spectroscopy of molecular complexes containing small polyatomic molecules. INT REV PHYS CHEM 2016. [DOI: 10.1080/0144235x.2016.1171039] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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3
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Perkins T, Herráez-Aguilar D, McCrudden G, Kłos J, Aoiz F, Brouard M. Surface-hopping trajectories for OH(A2Σ+) + Kr: Extension to the 1A″ state. J Chem Phys 2015; 142:144307. [DOI: 10.1063/1.4916972] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- T. Perkins
- The Department of Chemistry, The Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - D. Herráez-Aguilar
- Departamento de Química Física, Facultad de Química, Universidad Complutense, 28040 Madrid, Spain
| | - G. McCrudden
- The Department of Chemistry, The Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - J. Kłos
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA
| | - F.J. Aoiz
- Departamento de Química Física, Facultad de Química, Universidad Complutense, 28040 Madrid, Spain
| | - M. Brouard
- The Department of Chemistry, The Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
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4
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Meyer H, Kłos J, Alexander MH. Near-IR spectrum of NO(X2Π)-Xe: a joint experimental-theoretical investigation. J Phys Chem A 2013; 117:11906-14. [PMID: 23731187 DOI: 10.1021/jp4031267] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Employing the method of constant photon energy sum (CONPHOENERS) scans, we measure the near-IR spectrum of NO-Xe in the region of the first vibrational overtone of the NO monomer. Three bands are detected, which are assigned as the origin band located at 3722.60 cm(-1) and as bands with excitation of one quantum of z-axis rotation (3726.07 cm(-1)) and one quantum of bending vibration (3739.02 cm(-1)), respectively. The partially resolved rotational and electronic fine structures of the bands are analyzed with the help of a full quantum mechanical bound-state calculation using the ab initio potential energy surfaces of Kłos et al. (J. Chem. Phys. 2012, 137, 014312/1-014312/14). We perform a linear least-squares fit to the calculated energy levels to determine a set of spectroscopic constants that describe not only the overall rotation of the complex but also the electrostatic splitting due to the sum potential and the P-type doubling due to the difference potential. Using these results as guidance, we are able to simulate the experimental spectra. The comparison with the results from the theoretical treatment confirms the high quality of the ab initio treatment. The position of the excited bands is predicted with sub-wavenumber accuracy. Also, the rotational constants for all bands are found within less than 5%. Some differences are found for the amount of P-type doubling, which is overestimated by the theoretical treatment. Constants for the electrostatic splitting are in reasonable agreement for the origin band. Larger deviations are found for the vibrationally excited band, which points toward some inaccuracies in the potential energy surfaces.
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Affiliation(s)
- H Meyer
- Department of Physics and Astronomy, The University of Georgia , Athens, Georgia 30602-2451, United States
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5
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Dagdigian PJ, Alexander MH. Exact quantum scattering calculations of transport properties: CH2(X̃3B1, ã1A1)–helium. J Chem Phys 2013; 138:164305. [DOI: 10.1063/1.4801789] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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6
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Hapka M, Żuchowski PS, Szczęśniak MM, Chałasiński G. Symmetry-adapted perturbation theory based on unrestricted Kohn-Sham orbitals for high-spin open-shell van der Waals complexes. J Chem Phys 2013; 137:164104. [PMID: 23126692 DOI: 10.1063/1.4758455] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Two open-shell formulations of the symmetry-adapted perturbation theory are presented. They are based on the spin-unrestricted Kohn-Sham (SAPT(UKS)) and unrestricted Hartree-Fock (SAPT(UHF)) descriptions of the monomers, respectively. The key reason behind development of SAPT(UKS) is that it is more compatible with density functional theory (DFT) compared to the previous formulation of open-shell SAPT based on spin-restricted Kohn-Sham method of Żuchowski et al. [J. Chem. Phys. 129, 084101 (2008)]. The performance of SAPT(UKS) and SAPT(UHF) is tested for the following open-shell van der Waals complexes: He···NH, H(2)O···HO(2), He···OH, Ar···OH, Ar···NO. The results show an excellent agreement between SAPT(UKS) and SAPT(ROKS). Furthermore, for the first time SAPT based on DFT is shown to be suitable for the treatment of interactions involving Π-state radicals (He···OH, Ar···OH, Ar···NO). In the interactions of transition metal dimers ((3)Σ(u)(+))Au(2) and ((13)Σ(g)(+))Cr(2) we show that SAPT is incompatible with the use of effective core potentials. The interaction energies of both systems expressed instead as supermolecular UHF interaction plus dispersion from SAPT(UKS) result in reasonably accurate potential curves.
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Affiliation(s)
- Michał Hapka
- Faculty of Chemistry, University of Warsaw, 02-093 Warsaw, Pasteura 1, Poland.
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7
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Raston PL, Liang T, Douberly GE. Anomalous Λ-Doubling in the Infrared Spectrum of the Hydroxyl Radical in Helium Nanodroplets. J Phys Chem A 2013; 117:8103-10. [DOI: 10.1021/jp312335q] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Paul L. Raston
- Department
of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Tao Liang
- 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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8
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Wilhelm MJ, Nikow M, Smith JM, Dai HL. Collisional Energy Transfer from Highly Vibrationally Excited Radicals Is Very Efficient. J Phys Chem Lett 2013; 4:23-29. [PMID: 26291206 DOI: 10.1021/jz301761e] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Although highly vibrationally excited (HVE) radicals are ubiquitous in natural environments, the effect of collisional energy transfer (ET) on their reactivity has yet to be fully characterized. We have used time-resolved IR emission spectroscopy to characterize the vibrational-to-translational quenching of a small HVE radical, ketenyl (HCCO), by inert gases. Photolysis of ethyl ethynyl ether at 193 nm provides HVE HCCO in the X̃(2)A″ electronic ground-state, with a nascent internal energy of 2.2 ± 0.6 eV. IR emission is monitored as an indicator of vibrational energy, and spectral modeling allows direct determination of the average energy lost per collision as a function of the internal energy. Collisional deactivation of HVE HCCO is shown to be minimally an order of magnitude more efficient than closed-shell molecules of comparable size. Schwartz-Slawsky-Herzfeld-Tanczos (SSHT) theory, modified for HVE molecules, suggests that this ET enhancement is due to a strong attractive intermolecular interaction.
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Affiliation(s)
- Michael J Wilhelm
- †Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Matthew Nikow
- †Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Jonathan M Smith
- ‡Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, United States
| | - Hai-Lung Dai
- ‡Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, United States
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9
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Chadwick H, Brouard M, Chang YP, Eyles CJ, Perkins T, Seamons SA, Kłos J, Alexander MH, Aoiz FJ. A new potential energy surface for OH(A 2Σ+)–Kr: The van der Waals complex and inelastic scattering. J Chem Phys 2012; 137:154305. [DOI: 10.1063/1.4757859] [Citation(s) in RCA: 11] [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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10
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Meyer H. The Ã-state dissociation continuum of NO-Ar and its near infrared spectrum. J Chem Phys 2012; 136:204308. [PMID: 22667561 DOI: 10.1063/1.4722885] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
After preparing NO-Ar in a vibrational state correlating with the first overtone vibration in NO, we recorded its hot band UV spectrum by monitoring simultaneously the intensity in the NO(+) and the NO(+)-Ar ion channels. In this way, the bound as well as the continuous part of the electronic Ã←X̃ spectrum are observed directly. Below the dissociation threshold, the intensity is found exclusively in the NO(+)-Ar ion channel while above it is found in the NO fragment ion channel. We observe simultaneously intensity in both ion channels only for a very narrow frequency range near the dissociation threshold. Structures in the dissociation spectrum correlate well with the thresholds for production of NO(A) in different rotational states. At frequencies well above the dissociation threshold, NO-Ar is detected efficiently as a NO fragment. This fact has been exploited to record the near IR spectrum of NO-Ar with significantly increased sensitivity. The dissociation detected spectra are essentially identical to our previous constant photon energy sum (CONPHOENERS) scans [B. Wen, Y. Kim, H. Meyer, J. Kłos, and M. H. Alexander, J. Phys. Chem. A 112, 9483 (2008)]. Several hot band spectra have been remeasured with improved sensitivity enabling a comprehensive analysis yielding for the first time spectroscopic constants for levels associated with the potential surfaces of NO-Ar correlating with NO(v(NO) = 0 and 2). Since many NO-X complexes do not have a strong bound Ã-state spectrum, although they do have a Ã-state dissociation continuum, there is the possibility to record their near IR spectra by employing dissociation detection.
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Affiliation(s)
- H Meyer
- Department of Physics and Astronomy, The University of Georgia, Athens, Georgia 30602-2451, USA
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11
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Sumiyoshi§ Y, Funahara I, Sato K, Ohshima Y, Endo Y. Three-dimensional intermolecular potential energy surfaces of the Kr–OH complex. Mol Phys 2010. [DOI: 10.1080/00268976.2010.499378] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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12
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Wen B, Meyer H, Kłos J. The structure of the NO(X (2)Pi)-N(2) complex: A joint experimental-theoretical study. J Chem Phys 2010; 132:154305. [PMID: 20423179 DOI: 10.1063/1.3380666] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report the first measurement of the spectrum of the NO-N(2) complex in the region of the first vibrational NO overtone transition. The origin band of the complex is blueshifted by 0.30 cm(-1) from the corresponding NO monomer frequency. The observed spectrum consists of three bands assigned to the origin band, the excitation of one quantum of z-axis rotation and one associated hot band. The spacing of the bands and the rotational structure indicate a T-shaped vibrationally averaged structure with the NO molecule forming the top of the T. These findings are confirmed by high level ab initio calculations of the potential energy surfaces in planar symmetry. The deepest minimum is found for a T-shaped geometry on the A(")-surface. As a result the sum potential also has the global minimum for this structure. The different potential surfaces show several additional local minima at slightly higher energies indicating that the complex most likely will perform large amplitude motion even in its ground vibrational state. Nevertheless, as suggested by the measured spectra, the complex must, on average, spend a substantial amount of time near the T-shaped configuration.
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Affiliation(s)
- B Wen
- Department of Physics and Astronomy, The University of Georgia, Athens, Georgia 30602-2451, USA
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13
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Scharfenberg L, Kłos J, Dagdigian PJ, Alexander MH, Meijer G, van de Meerakker SYT. State-to-state inelastic scattering of Stark-decelerated OH radicals with Ar atoms. Phys Chem Chem Phys 2010; 12:10660-70. [DOI: 10.1039/c004422a] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Sumiyoshi Y, Funahara I, Sato K, Ohshima Y, Endo Y. Microwave spectroscopy of the Ne–OH(2Πi) complex and three-dimensional intermolecular potentials. Phys Chem Chem Phys 2010; 12:8340-9. [DOI: 10.1039/c002193h] [Citation(s) in RCA: 6] [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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Abstract
We report the first measurement of the near IR spectrum of the NO-CH(4) complex in the region of the first vibrational NO overtone transition in an IR-resonance enhanced multiphoton ionization double resonance experiment. The origin band is located at 3723.26 cm(-1), i.e., redshifted by 0.59 cm(-1) from the corresponding NO monomer frequency. The observed spectrum consists of two bands assigned to the origin band and the excitation of hindered rotation of the NO monomer in the complex similar to z-axis rotation. The spacing and the relative intensity of the bands are consistent with a structure in which NO resides preferentially in a position perpendicular to the intermolecular axis. The deviation from the linear configuration with C(3v) symmetry can be regarded as a Jahn-Teller (JT) distortion. Each band is dominated by two broad peaks with a few resolved rotational structures. The large spacing between the two peaks is indicative of significant angular momentum quenching, possibly another manifestation of the JT effect. The delay dependence between the IR and UV laser pulses reveals a lifetime of about 10 ns for the vibrationally excited complex due to vibrational predissociation. On the other hand, the linewidth of the narrowest spectral features indicates a much shorter excited state lifetime of about 100 ps, most likely due to intramolecular vibrational redistribution.
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Affiliation(s)
- B Wen
- Department of Physics and Astronomy, The University of Georgia, Athens, Georgia 30602-2451, USA
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16
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Wen B, Meyer H, Kłos J, Alexander MH. Joint experimental-theoretical investigation of the lower bound states of the NO(X2Pi)-Kr complex. J Phys Chem A 2009; 113:7366-75. [PMID: 19388642 DOI: 10.1021/jp811513j] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We describe the first measurement of the near IR spectrum of the NO-Kr van der Waals complex. A variant of IR-REMPI double-resonance spectroscopy is employed in which the IR and UV lasers are scanned simultaneously in such a way that throughout the scan the sum of the two photon energies is kept constant, matching a UV resonance of the system. In the region of the first overtone vibration of the NO monomer, we observe several rotationally resolved bands for the NO-Kr complex. In addition to the origin band located at 3723.046 cm(-1), we observe excited as well as hot bands involving the excitation of one or two quanta of z-axis rotation. Another band is assigned to the excitation of one quantum of bending vibration. The experimental spectra are compared with results of bound-state calculations for a new set of potential energy surfaces calculated at the spin-restricted coupled cluster level. For the average vibration-rotation energies, there is excellent agreement between the theoretical results based on the coupled states (CS) approximation and the full close-coupling (CC) treatment. Finer details like the electrostatic splitting and the P-type doubling of the rotational levels are accounted for only within the CC formalism. The comparison of the CC results with the measured spectra confirms the high quality of the PESs. However, the high resolution of the experiments is sufficient to identify some inaccuracies in the difference between the potential energy surfaces of A' and A'' reflection symmetry.
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Affiliation(s)
- Bo Wen
- Department of Physics and Astronomy, The University of Georgia, Athens, Georgia 30602-2451, USA
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17
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Aoiz FJ, Brouard M, Eyles CJ, Kłos J, de Miranda MP. The collisional depolarization of Σ2S+1 radicals by closed shell atoms: Theory and application to OH(A Σ2+)+Ar. J Chem Phys 2009; 130:044305. [DOI: 10.1063/1.3061496] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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18
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Paterson G, Marinakis S, Costen ML, McKendrick KG, Kłos J, Toboła R. Orientation and alignment depolarization in OH(X Π2)+Ar/He collisions. J Chem Phys 2008; 129:074304. [DOI: 10.1063/1.2967861] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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19
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Kłos J, Alexander MH, Brouard M, Eyles CJ, Aoiz FJ. A new potential energy surface for OH(A Σ2+)–Ar: The van der Waals complex and scattering dynamics. J Chem Phys 2008; 129:054301. [DOI: 10.1063/1.2957745] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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20
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Wen B, Kim Y, Meyer H, Kłos J, Alexander MH. IR-REMPI Double Resonance Spectroscopy: The Near-IR Spectrum of NO−Ar Revisited. J Phys Chem A 2008; 112:9483-93. [DOI: 10.1021/jp802765z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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21
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Han J, Heaven MC, Schnupf U. Spectroscopy, dissociation dynamics, and potential energy surfaces for CN(A)-Ar. J Chem Phys 2008; 128:224309. [PMID: 18554015 DOI: 10.1063/1.2936123] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The A (2)Pi-X (2)Sigma(+) band system of CN-Ar has been examined using fluorescence depletion and action spectroscopy techniques. Eight vibronic bands of the complex were observed in association with the monomer 3-0 transition. Pump-probe measurements were used to characterize CN(A (2)Pi(32),nu=3) fragments from direct photodissociation of CN(A (2)Pi,nu=3)-Ar and CN(X (2)Sigma(+),nu=7) fragments from CN(A (2)Pi,nu=3)-Ar predissociation. The latter showed a marked preference for population of positive parity diatomic rotational levels. Bound state calculations were used to assign the A-X bands and to obtain fitted potential energy surfaces for the A state. The average potential obtained from fitting had a well depth of D(e)=137.8 cm(-1). High-level ab initio calculations were used to obtain equilibrium Jacobi coordinates of theta(e)=94 degrees and R(e)=7.25 bohr. The near-symmetric character of the fitted potential energy surface was consistent with the symmetry preference observed in the predissociation dynamics.
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Affiliation(s)
- Jiande Han
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
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22
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Han J, Heaven MC, Schnupf U, Alexander MH. Experimental and theoretical studies of the CN–Ar van der Waals complex. J Chem Phys 2008; 128:104308. [DOI: 10.1063/1.2834932] [Citation(s) in RCA: 15] [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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23
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Tsai MT, Tsai PY, Alexander MH, Lin KC. Spin-Resolved Rotational Energy Transfer for the CH B2Σ−(v=0, N, F) State by Collisions with Ar. Chemphyschem 2008; 9:572-8. [DOI: 10.1002/cphc.200700779] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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24
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Fawzy WM, Heaven MC. Ab initio investigation of the NH(X)-N2 van der Waals complex. J Chem Phys 2007; 126:154311. [PMID: 17461630 DOI: 10.1063/1.2722260] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The NH-N(2) van der Waals complex has been examined at the CCSD(T) level of theory using aug-cc-pVDZ and aug-cc-pVTZ basis sets. The full basis set superposition error correction was applied. Two minimum energy structures were located for the electronic ground state. The global minimum corresponds to a linear geometry of the complex (NH-N-N), with D(e)=236 cm(-1) and R(c.m.)=4.22 A. The secondary minimum corresponds to a T-shaped geometry of C(2v) symmetry, where the nitrogen atom of the H-N moiety points toward the center of mass of the N(2) unit, aligned with the a-inertial axis of the complex. The binding energy and R(c.m.) value for the secondary minimum were 144 cm(-1) and 3.63 A, respectively. This potential energy surface is consistent with the properties of matrix-isolated NH-N(2), and it is predicted that linear NH-N(2) will be a stable complex in the gas phase at low temperatures.
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Affiliation(s)
- Wafaa M Fawzy
- Department of Chemistry, East Tennessee State University, Johnson City, TN 37614, USA
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25
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Küpper J, Merritt JM. Spectroscopy of free radicals and radical containing entrance-channel complexes in superfluid helium nanodroplets. INT REV PHYS CHEM 2007. [DOI: 10.1080/01442350601087664] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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26
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Merritt JM, Küpper J, Miller RE. A high-resolution infrared spectroscopic investigation of the halogen atom–HCN entrance channel complexes solvated in superfluid helium droplets. Phys Chem Chem Phys 2007; 9:401-16. [PMID: 17199157 DOI: 10.1039/b611340k] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Rotationally resolved infrared spectra are reported for the X-HCN (X = Cl, Br, I) binary complexes solvated in helium nanodroplets. These results are directly compared with those obtained previously for the corresponding X-HF complexes [J. M. Merritt, J. Küpper and R. E. Miller, Phys. Chem. Chem. Phys., 2005, 7, 67]. For bromine and iodine atoms complexed with HCN, two linear structures are observed and assigned to the (2)Sigma(1/2) and (2)Pi(3/2) ground electronic states of the nitrogen and hydrogen bound geometries, respectively. Experiments for HCN + chlorine atoms give rise to only a single band which is attributed to the nitrogen bound isomer. That the hydrogen bound isomer is not stabilized is rationalized in terms of a lowering of the isomerization barrier by spin-orbit coupling. Theoretical calculations with and without spin-orbit coupling have also been performed and are compared with our experimental results. The possibility of stabilizing high-energy structures containing multiple radicals is discussed, motivated by preliminary spectroscopic evidence for the di-radical Br-HCCCN-Br complex. Spectra for the corresponding molecular halogen HCN-X(2) complexes are also presented.
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Affiliation(s)
- Jeremy M Merritt
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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27
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Marinakis S, Paterson G, Kłos J, Costen ML, McKendrick KG. Inelastic scattering of OH(X 2Π) with Ar and He: a combined polarization spectroscopy and quantum scattering study. Phys Chem Chem Phys 2007; 9:4414-26. [PMID: 17687488 DOI: 10.1039/b703909c] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
One-colour polarization spectroscopy (PS) on the OH A (2)Sigma(+)- X (2)Pi(0,0) band has been used to measure the removal of bulk rotational angular momentum alignment of ground-state OH(X (2)Pi) in collisions with He and Ar. Pseudo-first-order PS signal decays at different collider partial pressures were used to determine second-order decay rate constants for the X (2)Pi(3/2), J = 1.5-6.5, e states. The PS signal decay rate constant, k(PS), is sensitive to all processes that remove population and destroy polarization. The contribution to k(PS) from pure (elastic) alignment depolarization within the initial level, k(DEP), can be extracted by subtracting the independently measured or predicted sum of the rate constants for total rotational energy transfer (RET), k(RET), and for Lambda-doublet changing, k(Lambda), collisions from k(PS). Literature values of k(RET) and k(Lambda) are available from experiments with He and Ar, and from quantum scattering calculations for Ar only. We therefore also present the results of new, exact, fully quantum mechanical calculations of k(RET) and k(Lambda) on the most recent ab initio OH(X)-He potential energy surface of Lee et al. [J. Chem. Phys. 2000, 113, 5736]. The results for k(DEP) from this subtraction for He are found to be modest, around 0.4 x 10(-10) cm(3) s(-1), whereas for Ar k(DEP) is found to range between 0.6 +/- 0.2 x 10(-10) cm(3) s(-1) and 1.7 +/- 0.3 x 10(-10) cm(3) s(-1), comparable to total population removal rate constants. The differences between k(DEP) for the two colliders are most likely explained by the presence of a substantially deeper attractive well for Ar than for He. The measurement of k(DEP) may provide a useful new tool that is more sensitive to the form of the long-range part of the intermolecular potential than rotational state-changing collisions.
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Affiliation(s)
- Sarantos Marinakis
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, UK
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Doyle RJ, Hirst DM, Hutson JM. Ab initio potential energy surfaces, bound states, and electronic spectrum of the Ar–SH complex. J Chem Phys 2006; 125:184312. [PMID: 17115757 DOI: 10.1063/1.2371080] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
New ab initio potential energy surfaces for the (2)Pi ground electronic state of the Ar-SH complex are presented, calculated at the RCCSD(T)/aug-cc-pV5Z level. Weakly bound rotation-vibration levels are calculated using coupled-channel methods that properly account for the coupling between the two electronic states. The resulting wave functions are analyzed and a new adiabatic approximation including spin-orbit coupling is proposed. The ground-state wave functions are combined with those obtained for the excited (2)Sigma(+) state [D. M. Hirst, R. J. Doyle, and S. R. Mackenzie, Phys. Chem. Chem. Phys. 6, 5463 (2004)] to produce transition dipole moments. Modeling the transition intensities as a combination of these dipole moments and calculated lifetime values [A. B. McCoy, J. Chem. Phys. 109, 170 (1998)] leads to a good representation of the experimental fluorescence excitation spectrum [M.-C. Yang, A. P. Salzberg, B.-C. Chang, C. C. Carter, and T. A. Miller, J. Chem. Phys. 98, 4301 (1993)].
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Affiliation(s)
- Richard J Doyle
- Department of Chemistry, University of Sheffield, Sheffield S3 7HF, UK.
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Sumiyoshi Y, Funahara I, Sato K, Ohshima Y, Endo Y. Three-dimensional potential energy surface of the Ar–OH(Πi2) complex. J Chem Phys 2006; 125:124307. [PMID: 17014174 DOI: 10.1063/1.2353120] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Pure rotational transitions in the ground state for Ar-OH and Ar-OD [Y. Ohshima et al., J. Chem. Phys. 95, 7001 (1991) and Y. Endo et al., Faraday Discuss. 97, 341 (1994)], those in the excited states of the OH vibration, nu(s)=1 and 2, observed by Fourier-transform microwave spectroscopy in the present study, rotation-vibration transitions observed by infrared-ultraviolet double-resonance spectroscopy [K. M. Beck et al., Chem. Phys. Lett. 162, 203 (1989) and R. T. Bonn et al., J. Chem. Phys. 112, 4942 (2000)], and the P-level structure observed by stimulated emission pumping spectroscopy [M. T. Berry et al., Chem. Phys. Lett. 178, 301 (1991)] have been simultaneously analyzed to determine the potential energy surface of Ar-OH in the ground state. A Schrodinger equation, considering all the freedom of motions for an atom-diatom system in the Jacobi coordinate, R, theta, and r, was numerically solved to obtain energies of the rovibrational energy levels using the discrete variable representation method. A three-dimensional potential energy surface is determined by a least-squares fitting. In the analysis the potential parameters, obtained by ab initio calculations at the RCCSD(T) level of theory with a set of basis functions of aug-cc-pVTZ and midbond functions, are used as initial values. The determined intermolecular potential energy surface and its dependence on the OH monomer bond length are compared with those of an isovalent radical complex, Ar-SH.
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Affiliation(s)
- Yoshihiro Sumiyoshi
- Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan
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Vissers GWM, McCoy AB. Time-Dependent Wave Packet Studies on the Cl + HCl Hydrogen Exchange Reaction. J Phys Chem A 2006; 110:5978-81. [PMID: 16671664 DOI: 10.1021/jp061196d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The initiation of the hydrogen exchange reaction Cl((2)P)+HCl --> ClH+Cl((2)P) by excitation of the HCl molecular stretch to v=2 is studied for total angular momentum quantum number J=(1)/(2) and both even and odd parity. The calculations were performed using a time-dependent propagation from an initial quasi-bound state and employed all three relevant potential energy surfaces and the nonadiabatic couplings between them. Coriolis and spin-orbit coupling were also taken into account. The electronic and HCl rotational distributions of the products in both dissociation channels are analyzed, and the results are interpreted using features of the potential energy surfaces.
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Affiliation(s)
- Gé W M Vissers
- Department of Chemistry, The Ohio State University, Columbus, Ohio 43210, USA
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McCoy AB. Diffusion Monte Carlo approaches for investigating the structure and vibrational spectra of fluxional systems. INT REV PHYS CHEM 2006. [DOI: 10.1080/01442350600679347] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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