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Dey D, Woodhouse JL, Taylor MP, Fielding HH, Worth GA. On the multiphoton ionisation photoelectron spectra of phenol. Phys Chem Chem Phys 2024; 26:3451-3461. [PMID: 38205824 DOI: 10.1039/d3cp05559k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
The phenol molecule is a prototype for non-adiabatic dynamics and the excited-state photochemistry of biomolecules. In this article, we report a joint theoretical and experimental investigation on the resonance enhanced multiphoton ionisation photoelectron (REMPI) spectra of the two lowest ionisation bands of phenol. The focus is on the theoretical interpretation of the measured spectra using quantum dynamics simulations. These were performed by numerically solving the time-dependent Schrödinger equation using the multi-layer variant of the multiconfiguration time-dependent Hartree algorithm together with a vibronic coupling Hamiltonian model. The ionising laser pulse is modelled explicitly within the ionisation continuum model to simulate experimental femtosecond 1+1 REMPI photoelectron spectra. These measured spectra are sensitive to very short lived electronically excited states, providing a rigorous benchmark for our theoretical methods. The match between experiment and theory allows for an interpretation of the features of the spectra at different wavelengths and shows that there are features due to both 'direct' and 'indirect' ionisation, resulting from non-resonant and resonant excitation by the pump pulse.
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Affiliation(s)
- Diptesh Dey
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA
| | - Joanne L Woodhouse
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
- Department of Chemistry, University of Southampton, Southampton, SO17 1BJ, UK
| | - Marcus P Taylor
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
| | - Helen H Fielding
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
| | - Graham A Worth
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
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Hoshino S, Ishii K, Tsukiyama K. Predissociation Dynamics of Br 2 in the [ 2Π 1/2] c5d; 0 g + and [ 2Π 3/2] c6d; 0 g + Rydberg States by Velocity Map Imaging Study. ACS OMEGA 2022; 7:29072-29078. [PMID: 36033697 PMCID: PMC9404482 DOI: 10.1021/acsomega.2c02921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 08/01/2022] [Indexed: 06/15/2023]
Abstract
We investigated the predissociation dynamics from the [2Π1/2]c5d; 0g + and [2Π3/2]c6d; 0g + Rydberg states of Br2 using the velocity map imaging technique. Two-dimensional scattering images of the fragmented Br+ exhibited an isotropic feature upon the excitation of these Rydberg states. Analysis of the total kinetic energy release suggested the existence of the predissociation pathways to the dissociation limits of Br(5s, 4P3/2) + Br(4p, 2P3/2) and Br(5s, 4P5/2) + Br(4p, 2P3/2) via the 0g + ion-pair states that interact with the lower and/or excited-core Rydberg states lying at long internuclear distance regions thorough the avoided crossing.
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3
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Reilly C, Hutchison A, Sitz GO. Survival of rotational alignment in H 2 scattering from Si(100). J Chem Phys 2021; 155:174705. [PMID: 34742218 DOI: 10.1063/5.0068518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We report a state-prepared, state-resolved study of rotational scattering of a diatomic molecule from a solid surface. Specifically, H2 molecules with 80 meV kinetic energy are rotationally aligned in the j = 3 rotational state via stimulated Raman pumping and then scattered from a Si(100) surface at normal incidence. The rotational alignment of the scattered molecules is determined by measuring, for both the incident and scattered molecules, the ionization yield of a probe laser, tuned to selectively ionize molecules in the j = 3 rotation level, as the probe laser polarization is rotated. The measurement is performed for two initial rotational alignments: a "helicoptering" alignment with the bonds constrained to lie primarily parallel to the surface and a "cartwheeling" alignment with the bonds lying primarily normal to the surface. For both initial alignments, the modulation of the probe ionization yield with laser polarization for the scattered molecules is pronounced, although significantly weaker than the modulation measured for the incident molecules. This indicates a significant modification but not a complete elimination of the initial alignment. The modulation is found to be stronger for the scattered molecules originating in the cartwheeling alignment than for the helicoptering alignment. These results contribute toward an improved understanding of the role of rotational motion in molecule-surface dynamics.
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Affiliation(s)
- Christopher Reilly
- Department of Physics, University of Texas at Austin, Austin, Texas 78712-1081, USA
| | - Andrew Hutchison
- Department of Physics, University of Texas at Austin, Austin, Texas 78712-1081, USA
| | - Greg O Sitz
- Department of Physics, University of Texas at Austin, Austin, Texas 78712-1081, USA
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Sun ZF, von Zastrow AD, Parker DH. A simple resonance enhanced laser ionization scheme for CO via the A 1Π state. J Chem Phys 2017; 147:013909. [PMID: 28688421 DOI: 10.1063/1.4977986] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
We investigate the laser ionization process taking place when the CO molecule is exposed to vacuum ultraviolet (VUV) radiation resonant with the CO A1Π(v = 0) ← X1Σ+(v = 0) transition around 154 nm, along with the ultraviolet (UV) and visible (Red) radiation used to generate VUV by four-wave difference-frequency mixing. By measuring the CO+ ion recoil and a room temperature gas spectrum, it is possible to assign the ionization process as 1 + 1' + 1'' REMPI where the one-photon steps refer to the VUV, UV, and Red radiation, respectively. Resonance enhanced ionization of rotational states around J = 12 arise due to the overlap of the fixed wavelength UV (∼250 nm) with the R band-head of a transition assigned to CO E1Π(v = 6) ← A1Π(v = 0) with a term value of 104 787.5 cm-1. The REMPI process is efficient and polarization sensitive and should be useful in a wide range of studies involving nascent CO.
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Affiliation(s)
- Z F Sun
- Department of Molecular and Laser Physics, Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - A D von Zastrow
- Department of Molecular and Laser Physics, Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - D H Parker
- Department of Molecular and Laser Physics, Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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7
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Ingle RA, Hansen CS, Elsdon E, Bain M, King SJ, Lee JWL, Brouard M, Vallance C, Turchetta R, Ashfold MNR. Ultraviolet photochemistry of 2-bromothiophene explored using universal ionization detection and multi-mass velocity-map imaging with a PImMS2 sensor. J Chem Phys 2017; 147:013914. [DOI: 10.1063/1.4979559] [Citation(s) in RCA: 9] [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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Bhattacherjee A, Wategaonkar S. Role of the C(2)–H Hydrogen Bond Donor in Gas-Phase Microsolvation of Imidazole Derivatives with ROH (R = CH3, C2H5). J Phys Chem A 2017; 121:4283-4295. [DOI: 10.1021/acs.jpca.7b03329] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Aditi Bhattacherjee
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005, India
| | - Sanjay Wategaonkar
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005, India
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Ashfold MN, Murdock D, Oliver TA. Molecular Photofragmentation Dynamics in the Gas and Condensed Phases. Annu Rev Phys Chem 2017; 68:63-82. [DOI: 10.1146/annurev-physchem-052516-050756] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Exciting a molecule with an ultraviolet photon often leads to bond fission, but the final outcome of the bond cleavage is typically both molecule and phase dependent. The photodissociation of an isolated gas-phase molecule can be viewed as a closed system: Energy and momentum are conserved, and the fragmentation is irreversible. The same is not true in a solution-phase photodissociation process. Solvent interactions may dissipate some of the photoexcitation energy prior to bond fission and will dissipate any excess energy partitioned into the dissociation products. Products that have no analog in the corresponding gas-phase study may arise by, for example, geminate recombination. Here, we illustrate the extent to which dynamical insights from gas-phase studies can inform our understanding of the corresponding solution-phase photochemistry and how, in the specific case of photoinduced ring-opening reactions, solution-phase studies can in some cases reveal dynamical insights more clearly than the corresponding gas-phase study.
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Affiliation(s)
| | - Daniel Murdock
- School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Thomas A.A. Oliver
- School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
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10
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Chen PC. An Introduction to Coherent Multidimensional Spectroscopy. APPLIED SPECTROSCOPY 2016; 70:1937-1951. [PMID: 27940533 DOI: 10.1177/0003702816669730] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 08/05/2016] [Indexed: 06/06/2023]
Abstract
Coherent multidimensional spectroscopy is a field that has drawn much attention as an optical analogue to multidimensional nuclear magnetic resonance imaging. Coherent multidimensional spectroscopic techniques produce spectra that show the magnitude of an optical signal as a function of two or more pulsed laser frequencies. Spectra can be collected in either the frequency or the time domain. In addition to improving resolution and overcoming spectral congestion, coherent multidimensional spectroscopy provides the ability to investigate and conduct studies based upon the relationship between different peaks. The purpose of this paper is to provide a general introduction to the area of coherent multidimensional spectroscopy, to provide a brief overview of current experimental approaches, and to discuss some emerging developments in this relatively young field.
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11
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Onvlee J, Vogels SN, van de Meerakker SYT. Unraveling Cold Molecular Collisions: Stark Decelerators in Crossed-Beam Experiments. Chemphyschem 2016; 17:3583-3595. [PMID: 27471830 DOI: 10.1002/cphc.201600604] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Indexed: 11/11/2022]
Abstract
In the last two decades, enormous progress has been made in the manipulation of molecular beams. In particular, molecular decelerators have been developed with which advanced control over neutral molecules in a beam can be achieved. By using arrays of inhomogeneous and time-varying electric (or magnetic) fields, bunches of molecules can be produced with a tunable velocity, narrow velocity spreads, and almost perfect quantum-state purity. These monochromatic or "tamed" molecular beams are ideally suited to be used in crossed-molecular-beam scattering experiments. Here, we review the first generation of these "cold and controlled" scattering experiments that have been conducted in the last decade and discuss the prospects for this emerging field of research in the years to come.
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Affiliation(s)
- Jolijn Onvlee
- Radboud University, Institute for Molecules and Materials, Heijendaalseweg 135, 6525 AJ, Nijmegen, the Netherlands
| | - Sjoerd N Vogels
- Radboud University, Institute for Molecules and Materials, Heijendaalseweg 135, 6525 AJ, Nijmegen, the Netherlands
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Rodrigues NDN, Staniforth M, Stavros VG. Photophysics of sunscreen molecules in the gas phase: a stepwise approach towards understanding and developing next-generation sunscreens. Proc Math Phys Eng Sci 2016; 472:20160677. [PMID: 27956888 PMCID: PMC5134319 DOI: 10.1098/rspa.2016.0677] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 10/24/2016] [Indexed: 12/22/2022] Open
Abstract
The relationship between exposure to ultraviolet (UV) radiation and skin cancer urges the need for extra photoprotection, which is presently provided by widespread commercially available sunscreen lotions. Apart from having a large absorption cross section in the UVA and UVB regions of the electromagnetic spectrum, the chemical absorbers in these photoprotective products should also be able to dissipate the excess energy in a safe way, i.e. without releasing photoproducts or inducing any further, harmful, photochemistry. While sunscreens are tested for both their photoprotective capability and dermatological compatibility, phenomena occurring at the molecular level upon absorption of UV radiation are largely overlooked. To date, there is only a limited amount of information regarding the photochemistry and photophysics of these sunscreen molecules. However, a thorough understanding of the intrinsic mechanisms by which popular sunscreen molecular constituents dissipate excess energy has the potential to aid in the design of more efficient, safer sunscreens. In this review, we explore the potential of using gas-phase frequency- and time-resolved spectroscopies in an effort to better understand the photoinduced excited-state dynamics, or photodynamics, of sunscreen molecules. Complementary computational studies are also briefly discussed. Finally, the future outlook of expanding these gas-phase studies into the solution phase is considered.
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Germann M, Willitsch S. Fine- and hyperfine-structure effects in molecular photoionization. II. Resonance-enhanced multiphoton ionization and hyperfine-selective generation of molecular cations. J Chem Phys 2016; 145:044315. [PMID: 27475369 DOI: 10.1063/1.4955303] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Resonance-enhanced multiphoton ionization (REMPI) is a widely used technique for studying molecular photoionization and producing molecular cations for spectroscopy and dynamics studies. Here, we present a model for describing hyperfine-structure effects in the REMPI process and for predicting hyperfine populations in molecular ions produced by this method. This model is a generalization of our model for fine- and hyperfine-structure effects in one-photon ionization of molecules presented in Paper I [M. Germann and S. Willitsch, J. Chem. Phys. 145, 044314 (2016)]. This generalization is achieved by covering two main aspects: (1) treatment of the neutral bound-bound transition including the hyperfine structure that makes up the first step of the REMPI process and (2) modification of our ionization model to account for anisotropic populations resulting from this first excitation step. Our findings may be used for analyzing results from experiments with molecular ions produced by REMPI and may serve as a theoretical background for hyperfine-selective ionization experiments.
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Affiliation(s)
- Matthias Germann
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, 4056 Basel, Switzerland
| | - Stefan Willitsch
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, 4056 Basel, Switzerland
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14
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Biswal HS, Bhattacharyya S, Bhattacherjee A, Wategaonkar S. Nature and strength of sulfur-centred hydrogen bonds: laser spectroscopic investigations in the gas phase and quantum-chemical calculations. INT REV PHYS CHEM 2015. [DOI: 10.1080/0144235x.2015.1022946] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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15
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Zack LN, Maier JP. Laboratory spectroscopy of astrophysically relevant carbon species. Chem Soc Rev 2014; 43:4602-14. [PMID: 24676285 DOI: 10.1039/c4cs00049h] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Carbon is one of the most common elements in the solar system, with a fractional abundance of 10(-4) relative to hydrogen. Thus, it is not surprising that over 100 carbon-bearing species have been definitively detected in the interstellar medium via their rotational, infrared, and/or electronic transitions. In order to identify these species, laboratory spectra are needed for comparison to astronomical data. Challenges arise when obtaining laboratory spectra due to the instability of many of these molecules. Over the years, sensitive instrumentation and better techniques for producing these species in situ have been developed to achieve this goal. The use of complementary spectroscopic methods, such as matrix isolation, cavity ringdown, resonance enhanced multiphoton ionization, and ion trapping have led to the identification of several new carbon species at optical and ultraviolet wavelengths. Laboratory spectra have been compared to astronomical data in order to gain further insight into interstellar chemistry. In particular, attempts have been made to identify the carriers of the diffuse interstellar bands, however, with little success. These results are discussed in the following review.
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Affiliation(s)
- Lindsay N Zack
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland.
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16
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Korobenko A, Milner AA, Hepburn JW, Milner V. Rotational spectroscopy with an optical centrifuge. Phys Chem Chem Phys 2014; 16:4071-6. [DOI: 10.1039/c3cp54598a] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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17
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Onvlee J, Vogels SN, Zastrow AV, Parker DH, van de Meerakker SYT. Molecular collisions coming into focus. Phys Chem Chem Phys 2014; 16:15768-79. [DOI: 10.1039/c4cp01519c] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Control over molecules in a Stark decelerator enables the measurement of diffraction oscillations in NO-atom scattering.
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Affiliation(s)
- Jolijn Onvlee
- Radboud University Nijmegen
- Institute for Molecules and Materials
- 6525 AJ Nijmegen, the Netherlands
| | - Sjoerd N. Vogels
- Radboud University Nijmegen
- Institute for Molecules and Materials
- 6525 AJ Nijmegen, the Netherlands
| | - Alexander von Zastrow
- Radboud University Nijmegen
- Institute for Molecules and Materials
- 6525 AJ Nijmegen, the Netherlands
| | - David H. Parker
- Radboud University Nijmegen
- Institute for Molecules and Materials
- 6525 AJ Nijmegen, the Netherlands
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18
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Marx S, Adu Smith D, Abel MJ, Zehentbauer T, Meijer G, Santambrogio G. Imaging cold molecules on a chip. PHYSICAL REVIEW LETTERS 2013; 111:243007. [PMID: 24483656 DOI: 10.1103/physrevlett.111.243007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Indexed: 06/03/2023]
Abstract
We present the integrated imaging of cold molecules in a microchip environment. The on-chip detection is based on resonance-enhanced multiphoton ionization, which is quantum state selective and generally applicable. We demonstrate and characterize time-resolved spatial imaging and subsequently use it to analyze the effect of a phase-space manipulation sequence aimed at compressing the velocity distribution of a molecular ensemble with a view to future high-resolution spectroscopic studies. The realization of such on-chip measurements adds the final fundamental component to the molecule chip, offering a new and promising route for investigating cold molecules.
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Affiliation(s)
- S Marx
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - D Adu Smith
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - M J Abel
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - T Zehentbauer
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - G Meijer
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany and Radboud University of Nijmegen, Institute for Molecules and Materials, Heijendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - G Santambrogio
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
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Zhang S, Lu C, Jia T, Qiu J, Sun Z. Control of resonance enhanced multi-photon ionization photoelectron spectroscopy by phase-shaped femtosecond laser pulse. J Chem Phys 2012; 137:174301. [DOI: 10.1063/1.4762865] [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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20
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Toffoli D, Decleva P. Density functional theory for molecular multiphoton ionization in the perturbative regime. J Chem Phys 2012; 137:134103. [DOI: 10.1063/1.4754820] [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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21
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Nemirow C, Fine J, Lu Z, Diri K, Krylov A, Wittig C. Photoionization of tris(2-phenylpyridine)iridium. Mol Phys 2012. [DOI: 10.1080/00268976.2012.689871] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Xu B, Coello Y, Lozovoy VV, Dantus M. Two-photon fluorescence excitation spectroscopy by pulse shaping ultrabroad-bandwidth femtosecond laser pulses. APPLIED OPTICS 2010; 49:6348-6353. [PMID: 21068867 DOI: 10.1364/ao.49.006348] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A fast and automated approach to measuring two-photon fluorescence excitation (TPE) spectra of fluorophores with high resolution (~2 nm) by pulse shaping ultrabroad-bandwidth femtosecond laser pulses is demonstrated. Selective excitation in the range of 675-990 nm was achieved by imposing a series of specially designed phase and amplitude masks on the excitation pulses using a pulse shaper. The method eliminates the need for laser tuning and is, thus, suitable for non-laser-expert use. The TPE spectrum of Fluorescein was compared with independent measurements and the spectra of the pH-sensitive dye 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) in acidic and basic environments were measured for the first time using this approach.
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Affiliation(s)
- Bingwei Xu
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
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24
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Upadhyaya HP, Saha A, Kumar A, Bandyopadhyay T, Naik PD, Bajaj P. Photodissociation Dynamics of Phosphorus Trichloride (PCl3) at 235 nm Using Resonance Enhanced Multiphoton Ionization (REMPI) with Time-of-Flight (TOF) Mass Spectrometry. J Phys Chem A 2010; 114:5271-8. [DOI: 10.1021/jp100538u] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Hari P. Upadhyaya
- Radiation & Photochemistry Division and Theoretical Chemistry Section, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | - Ankur Saha
- Radiation & Photochemistry Division and Theoretical Chemistry Section, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | - Awadhesh Kumar
- Radiation & Photochemistry Division and Theoretical Chemistry Section, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | - T. Bandyopadhyay
- Radiation & Photochemistry Division and Theoretical Chemistry Section, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | - Prakash D. Naik
- Radiation & Photochemistry Division and Theoretical Chemistry Section, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | - P.N. Bajaj
- Radiation & Photochemistry Division and Theoretical Chemistry Section, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
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Lorenz M, Schiewek R, Brockmann KJ, Schmitz OJ, Gäb S, Benter T. The distribution of ion acceptance in atmospheric pressure ion sources: spatially resolved APLI measurements. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2008; 19:400-410. [PMID: 18187335 DOI: 10.1016/j.jasms.2007.11.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2007] [Revised: 11/27/2007] [Accepted: 11/27/2007] [Indexed: 05/25/2023]
Abstract
It is demonstrated that spatially resolved mass selected analysis using atmospheric pressure laser ionization mass spectrometry (APLI MS) represents a new powerful tool for mechanistic studies of ion-molecule chemistry occurring within atmospheric pressure (AP) ion sources as well as for evaluation and optimization of ion source performance. A focused low-energy UV laser beam is positioned computer controlled orthogonally on a two-dimensional grid in the ion source enclosure. Resonance enhanced multiphoton ionization (REMPI) of selected analytes occurs only within the confined volume of the laser beam. Depending on the experimental conditions and the reactivity of the primary photo-generated ions, specific signal patterns become visible after data treatment, as visualized in, e.g., contour or pseudo-color plots. The resulting spatial dependence of sensitivity is defined in this context as the distribution of ion acceptance (DIA) of the source/analyzer combination. This approach provides a much more detailed analysis of the diverse processes occurring in AP ion sources compared with conventional bulk signal response measurements.
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Affiliation(s)
- Matthias Lorenz
- Department of Chemistry, University of Wuppertal, Wuppertal, Germany
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26
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Ow FP, Djurovich PI, Thompson ME, Zink JI. Wavelength-Dependent Photofragmentation of a Mixed-Ligand Cyclometalated Platinum(II) Coordination Compound in a Molecular Beam. Inorg Chem 2008; 47:2389-95. [DOI: 10.1021/ic701383y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Franklin P. Ow
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, and Department of Chemistry, University of Southern California, Los Angeles, California 90089
| | - Peter I. Djurovich
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, and Department of Chemistry, University of Southern California, Los Angeles, California 90089
| | - Mark E. Thompson
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, and Department of Chemistry, University of Southern California, Los Angeles, California 90089
| | - Jeffrey I. Zink
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, and Department of Chemistry, University of Southern California, Los Angeles, California 90089
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27
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Philis JG. Resonance-enhanced multiphoton ionization spectra of jet-cooled methanol and ethanol. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.10.089] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Vieuxmaire OPJ, Hendrik Nahler N, Dixon RN, Ashfold MNR. Multiphoton dissociation dynamics of BrCl and the BrCl+ cation. Phys Chem Chem Phys 2007; 9:5531-41. [DOI: 10.1039/b709222a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Osgood R. Photoreaction Dynamics of Molecular Adsorbates on Semiconductor and Oxide Surfaces. Chem Rev 2006; 106:4379-401. [PMID: 17031991 DOI: 10.1021/cr050175x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Richard Osgood
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, USA
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31
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Romanescu C, Loock HP. Photoelectron imaging following 2 + 1 multiphoton excitation of HBr. Phys Chem Chem Phys 2006; 8:2940-9. [PMID: 16880906 DOI: 10.1039/b602435a] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The photodissociation and photoionization dynamics of HBr via low-n Rydberg and ion-pair states was studied by using 2 + 1 REMPI spectroscopy and velocity map imaging of photoelectrons. Two-photon excitation at about 9.4-10 eV was used to prepare rotationally selected excited states. Following absorption of the third photon the unperturbed F (1)Delta(2) and i (3)Delta(2) states ionize directly into the ground vibrational state of the molecular ion according to the Franck-Condon principle and upon preservation of the ion core. In case of the V (1)Sigma(+)(0(+)) ion-pair state and the perturbed E (1)Sigma(+)(0(+)), g (3)Sigma(-)(0(+)), and H (1)Sigma(+)(0(+)) Rydberg states the absorption of the third photon additionally results in a long vibrational progression of HBr(+) in the X (2)Pi state as well as formation of electronically excited atomic photofragments. The vibrational excitation of the molecular ion is explained by autoionization of repulsive superexcited states into the ground state of the molecular ion. In contrast to HCl, the perturbed Rydberg states of HBr show strong participation of the direct ionization process, with ionic core preservation.
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Affiliation(s)
- Constantin Romanescu
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Canada ON K7L 3N6
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32
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Ashfold MNR, Nahler NH, Orr-Ewing AJ, Vieuxmaire OPJ, Toomes RL, Kitsopoulos TN, Garcia IA, Chestakov DA, Wu SM, Parker DH. Imaging the dynamics of gas phase reactions. Phys Chem Chem Phys 2006; 8:26-53. [PMID: 16482242 DOI: 10.1039/b509304j] [Citation(s) in RCA: 240] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ion imaging methods are making ever greater impact on studies of gas phase molecular reaction dynamics. This article traces the evolution of the technique, highlights some of the more important breakthroughs with regards to improving image resolution and in image processing and analysis methods, and then proceeds to illustrate some of the many applications to which the technique is now being applied--most notably in studies of molecular photodissociation and of bimolecular reaction dynamics.
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33
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Luo X, Niu D, Kong X, Wen L, Liang F, Pei K, Wang B, Li H. Cluster-assistant generation of multiply charged atomic ions in nanosecond laser ionization of seeded methyl iodide beam. Chem Phys 2005. [DOI: 10.1016/j.chemphys.2004.09.033] [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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34
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Constapel M, Schellenträger M, Schmitz OJ, Gäb S, Brockmann KJ, Giese R, Benter T. Atmospheric-pressure laser ionization: a novel ionization method for liquid chromatography/mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2005; 19:326-336. [PMID: 15645511 DOI: 10.1002/rcm.1789] [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
We report on the development of a new laser-ionization (LI) source operating at atmospheric pressure (AP) for liquid chromatography/mass spectrometry (LC/MS) applications. APLI is introduced as a powerful addition to existing AP ionization techniques, in particular atmospheric-pressure chemical ionization (APCI), electrospray ionization (ESI), and atmospheric pressure photoionization (APPI). Replacing the one-step VUV approach in APPI with step-wise two-photon ionization strongly enhances the selectivity of the ionization process. Furthermore, the photon flux during an ionization event is drastically increased over that of APPI, leading to very low detection limits. In addition, the APLI mechanism generally operates primarily directly on the analyte. This allows for very efficient ionization even of non-polar compounds such as polycyclic aromatic hydrocarbons (PAHs). The APLI source was characterized with a MicroMass Q-Tof Ultima II analyzer. Both the effluent of an HPLC column containing a number of PAHs (benzo[a]pyrene, fluoranthene, anthracene, fluorene) and samples from direct syringe injection were analyzed with respect to selectivity and sensitivity of the overall system. The liquid phase was vaporized by a conventional APCI inlet (AP probe) with the corona needle removed. Ionization was performed through selective resonance-enhanced multi-photon ionization schemes using a high-repetition-rate fixed-frequency excimer laser operating at 248 nm. Detection limits well within the low-fmol regime are readily obtained for various aromatic hydrocarbons that exhibit long-lived electronic states at the energy level of the first photon. Only molecular ions are generated at the low laser fluxes employed ( approximately 1 MW/cm(2)). The design and performance of the laser-ionization source are presented along with results of the analysis of aromatic hydrocarbons.
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Affiliation(s)
- M Constapel
- Division of Analytical Chemistry, University of Wuppertal, Gauss-Str. 20, 42119 Wuppertal, Germany
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35
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Sablier M, Fujii T. 3 Mass spectrometry of free radicals: a methodological overview. ACTA ACUST UNITED AC 2005. [DOI: 10.1039/b408852m] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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36
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Mazurenka M, Orr-Ewing AJ, Peverall R, Ritchie GAD. 4 Cavity ring-down and cavity enhanced spectroscopy using diode lasers. ACTA ACUST UNITED AC 2005. [DOI: 10.1039/b408909j] [Citation(s) in RCA: 201] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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37
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Nahler NH, Vieuxmaire OPJ, Jones JR, Ashfold MNR, Eppink ATJB, Coriou AM, Parker DH. High-Resolution Ion-Imaging Studies of the Photodissociation of the BrCl+ Cation. J Phys Chem A 2004. [DOI: 10.1021/jp049238q] [Citation(s) in RCA: 23] [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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38
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von Helden G, van Heijnsbergen D, Meijer G. Resonant Ionization Using IR Light: A New Tool To Study the Spectroscopy and Dynamics of Gas-Phase Molecules and Clusters. J Phys Chem A 2003. [DOI: 10.1021/jp021982s] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gert von Helden
- FOM-Institute for Plasmaphysics Rijnhuizen, Edisonbaan 14, NL-3439 MN Nieuwegein, The Netherlands, Department of Molecular and Laser Physics, University of Nijmegen, Toernooiveld 1, NL-6525 ED Nijmegen, The Netherlands, and Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Deniz van Heijnsbergen
- FOM-Institute for Plasmaphysics Rijnhuizen, Edisonbaan 14, NL-3439 MN Nieuwegein, The Netherlands, Department of Molecular and Laser Physics, University of Nijmegen, Toernooiveld 1, NL-6525 ED Nijmegen, The Netherlands, and Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Gerard Meijer
- FOM-Institute for Plasmaphysics Rijnhuizen, Edisonbaan 14, NL-3439 MN Nieuwegein, The Netherlands, Department of Molecular and Laser Physics, University of Nijmegen, Toernooiveld 1, NL-6525 ED Nijmegen, The Netherlands, and Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
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Abstract
We discuss experiments on the dynamics of photodissociation that employ methods to select the energy, sometimes quantum states, of the reactant and to determine the quantum states and energy, sometimes also the orientation and alignment, of products. A summary of new advances of experimental methods is followed by applications to photodissociation of various types. Representative examples of simple bond fission, molecular elimination, and three-body dissociation with determined electronic states-sometimes the orientation of their angular momentum-of product atoms or distributions of electronic and internal states of product molecules illustrate the detailed information and insight that one can derive from such experiments. Photodissociation of van der Waals complexes, ions, species adsorbed on surfaces, and species in solution is excluded from this review.
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Affiliation(s)
- Yuan-Pern Lee
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan.
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Himmel HJ, Downs AJ, Greene TM. Reactions of ground state and electronically excited atoms of main group elements: a matrix perspective. Chem Rev 2002; 102:4191-241. [PMID: 12428988 DOI: 10.1021/cr020405x] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hans-Jörg Himmel
- Institut für Anorganische Chemie, Universität Karlsruhe, Engesserstrasse, Geb 30.45, 76128 Karlsruhe, Germany.
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41
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Affiliation(s)
- Michel Sablier
- Département de Chimie, Laboratoire des Mécanismes Réactionnels, UMR 7651 du CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex, France
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42
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Abstract
We propose a scheme for molecule-based information processing by combining well-studied spectroscopic techniques and recent results from chemical dynamics. Specifically it is discussed how optical transitions in single molecules can be used to rapidly perform classical (Boolean) logical operations. In the proposed way, a restricted number of states in a single molecule can act as a logical gate equivalent to at least two switches. It is argued that the four-level scheme can also be used to produce gain, because it allows an inversion, and not only a switching ability. The proposed scheme is quantum mechanical in that it takes advantage of the discrete nature of the energy levels but, we here discuss the temporal evolution, with the use of the populations only. On a longer time range we suggest that the same scheme could be extended to perform quantum logic, and a tentative suggestion, based on an available experiment, is discussed. We believe that the pumping can provide a partial proof of principle, although this and similar experiments were not interpreted thus far in our terms.
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Affiliation(s)
- K L Kompa
- Max Planck Institute of Quantum Optics, D-85740 Garching, Germany
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43
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Moore NP, Levis RJ. The strong field photoelectron spectroscopy of acetylene: Evidence for short-lived 4p gerade states via electric field-induced resonance-enhanced multiphoton ionization. J Chem Phys 2000. [DOI: 10.1063/1.480683] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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44
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Chen KM. Laser Detection of Reaction Products: Slicing versus Projection Techniques. J CHIN CHEM SOC-TAIP 1999. [DOI: 10.1002/jccs.199900053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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45
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Structures in molecular photofragment and photoelectron distributions from two-photon non-resonant excitation. Chem Phys Lett 1999. [DOI: 10.1016/s0009-2614(98)01405-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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46
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Fang X, Ledingham KW, Graham P, Smith DJ, McCanny T, Singhal RP, Langley AJ, Taday PF. Uniform molecular analysis using femtosecond laser mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 1999; 13:1390-1397. [PMID: 10407329 DOI: 10.1002/(sici)1097-0231(19990730)13:14<1390::aid-rcm650>3.0.co;2-t] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The potential of femtosecond laser time-of-flight mass spectrometry (FLMS) for uniform quantitative analysis of molecules has been investigated. Various samples of molecular gases and vapours have been studied, using ultra-fast ( approximately 50 fs) laser pulses with very high intensity (up to 1.6 x 10(16) Wcm(-2)) for non-resonant multiphoton ionisation/tunnel ionisation. Some of these molecules have high ionisation potentials, requiring up to ten photons for non-resonant ionisation. The relative sensitivity factors (RSF) have been determined as a function of the laser intensity and it has been demonstrated that for molecules with very different masses and ionisation potentials, uniform ionisation has been achieved at the highest laser intensities. Quantitative laser mass spectrometry of molecules is therefore a distinct possibility. Copyright 1999 John Wiley & Sons, Ltd.
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Affiliation(s)
- X Fang
- Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, Scotland, UK
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47
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Pratt DW. HIGH RESOLUTION SPECTROSCOPY IN THE GAS PHASE: Even Large Molecules Have Well-Defined Shapes. Annu Rev Phys Chem 1998; 49:481-530. [PMID: 15012435 DOI: 10.1146/annurev.physchem.49.1.481] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
▪ Abstract A review of recent high-resolution microwave, infrared, and optical spectroscopy experiments demonstrates that remarkable progress has been made in the past 20 years in determining the equilibrium geometries of large polyatomic molecules and their clusters in the gas phase, and how these geometries change when the photon is absorbed. A special focus is on the dynamical information that can be obtained from such studies, particularly of electronically excited states.
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Affiliation(s)
- D W Pratt
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA. pratt+@pitt.edu
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48
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Langford SR, Orr-Ewing AJ, Morgan RA, Western CM, Ashfold MNR, Rijkenberg A, Scheper CR, Buma WJ, de Lange CA. The spectroscopy of high Rydberg states of ammonia. J Chem Phys 1998. [DOI: 10.1063/1.476082] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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49
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Abstract
▪ Abstract Laser and molecular beam techniques have enabled researchers to determine the rovibrational levels populated in collision-induced electronic transitions from specified initial levels of several diatomic molecules. As exemplified by the N2+– and CN–rare-gas systems, such measurements, in combination with theoretical calculations of cross sections for these state-to-state collisional processes, provide a means to understand in detail the dynamics of these electronic quenching and energy transfer processes. The present article reviews state-to-state studies of collision-induced electronic transitions. The various collision systems studied provide examples of both perturbation-assisted “gateways” between the initial and final electronic states and perturbation-independent transitions enabled by nonadiabatic mixing induced by the collision partner.
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Affiliation(s)
- P J Dagdigian
- Department of Chemistry, The Johns Hopkins University, Baltimore, MD 21218-2685, USA.
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50
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