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Liu Q, Gao Q, Liu P, Yang X, Yu S. Photodissociation of CO2 via the 1Πg state: Wavelength-dependent imaging studies of O(1D2) photoproducts. J Chem Phys 2024; 160:014301. [PMID: 38165095 DOI: 10.1063/5.0180860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 11/29/2023] [Indexed: 01/03/2024] Open
Abstract
Photodissociation of CO2 via the 1Πg state is investigated using a time-sliced velocity-mapped ion imaging apparatus combined with a tunable vacuum ultraviolet photolysis source. The main O(1D2) + CO(X1Σ+) channel is directly observed from the measured images of O(1D2) photoproducts at 129.08-134.76 nm. The total kinetic energy release spectra determined based on these images show that the energetic thresholds for the O(1D2) + CO(X1Σ+) photoproducts correspond to the thermochemical thresholds for the photodissociation of CO2(v2 = 0) and CO2(v2 = 1). One significant difference among the CO(X1Σ+, v) vibrational distributions for the predominant CO2(v2 = 0) dissociation is that the population of CO(v = 0) becomes favorable at 130.23-133.45 nm compared to the Boltzmann-like component (v > 0) that always exists at 129.08-134.76 nm. The wavelength dependences of the overall β are found to follow the variation trend of the CO(v = 0) abnormal intensity. The vibrational state-specific β values present a roughly decreasing trend with an increase in v, whereas β(v = 0) appears to be significantly larger than β(v = 1) at 130.23-133.45 nm compared to 134.76 and 129.08 nm. The non-statistical CO(v = 0) with larger β values at 130.23-133.45 nm implies that an additional pathway may open through the conical intersection coupling to the dissociative 21A' state, except for the ever-existing pathway that yields the Boltzmann-like component. In contrast, at 129.08 nm, the restoration of the statistical equilibrium in the CO(X1Σ+, v) vibrational distribution may be caused by the emergence of novel dissociation pathways arising from the participation of the 31A″ state.
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Affiliation(s)
- Qian Liu
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, Zhejiang Province, People's Republic of China
| | - Qinghua Gao
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, Zhejiang Province, People's Republic of China
| | - Peng Liu
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, Zhejiang Province, People's Republic of China
| | - Xueming Yang
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, Zhejiang Province, People's Republic of China
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, Liaoning Province, People's Republic of China
- Department of Chemistry, College of Science, Southern University of Science and Technology, 1088 Xueyuan Road, Shenzhen 518055, People's Republic of China
| | - Shengrui Yu
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, Zhejiang Province, People's Republic of China
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Zhang S, Wu Y, Zhang Z, Luo Z, Zhao Y, Li Z, Chang Y, Yang J, Wu G, Zhang W, Yu S, Yuan K, Yang X. Photodissociation dynamics of CO2 + hv → CO(X1Σ+) + O(1D2) via the 3P1Πu state. J Chem Phys 2022; 156:054302. [DOI: 10.1063/5.0081489] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Su’e Zhang
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, Zhejiang Province, People’s Republic of China
- State Key Laboratory of Molecular Reaction Dynamics and Dalian Coherent Light Source, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, Liaoning Province, People’s Republic of China
| | - Yucheng Wu
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, Zhejiang Province, People’s Republic of China
- State Key Laboratory of Molecular Reaction Dynamics and Dalian Coherent Light Source, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, Liaoning Province, People’s Republic of China
| | - Zhaoxue Zhang
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, Zhejiang Province, People’s Republic of China
- State Key Laboratory of Molecular Reaction Dynamics and Dalian Coherent Light Source, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, Liaoning Province, People’s Republic of China
| | - Zijie Luo
- State Key Laboratory of Molecular Reaction Dynamics and Dalian Coherent Light Source, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, Liaoning Province, People’s Republic of China
| | - Yarui Zhao
- State Key Laboratory of Molecular Reaction Dynamics and Dalian Coherent Light Source, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, Liaoning Province, People’s Republic of China
| | - Zhenxing Li
- State Key Laboratory of Molecular Reaction Dynamics and Dalian Coherent Light Source, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, Liaoning Province, People’s Republic of China
| | - Yao Chang
- State Key Laboratory of Molecular Reaction Dynamics and Dalian Coherent Light Source, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, Liaoning Province, People’s Republic of China
| | - Jiayue Yang
- State Key Laboratory of Molecular Reaction Dynamics and Dalian Coherent Light Source, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, Liaoning Province, People’s Republic of China
| | - Guorong Wu
- State Key Laboratory of Molecular Reaction Dynamics and Dalian Coherent Light Source, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, Liaoning Province, People’s Republic of China
| | - Weiqing Zhang
- State Key Laboratory of Molecular Reaction Dynamics and Dalian Coherent Light Source, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, Liaoning Province, People’s Republic of China
| | - Shengrui Yu
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, Zhejiang Province, People’s Republic of China
| | - Kaijun Yuan
- State Key Laboratory of Molecular Reaction Dynamics and Dalian Coherent Light Source, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, Liaoning Province, People’s Republic of China
| | - Xueming Yang
- State Key Laboratory of Molecular Reaction Dynamics and Dalian Coherent Light Source, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, Liaoning Province, People’s Republic of China
- Department of Chemistry, College of Science, Southern University of Science and Technology, Shenzhen 518055, People’s Republic of China
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Sakkoula E, Sharma G, Wang X, North SW, Parker DH, Wei W. Dynamics and vector correlations of vacuum ultraviolet (VUV) photodissociation of CO 2 at 155 nm. Phys Chem Chem Phys 2022; 24:2592-2600. [PMID: 35029267 DOI: 10.1039/d1cp04628d] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this work, the CO2 Vacuum Ultraviolet (VUV) photodissociation dynamics of the dominant O(1D) channel near 155 nm have been studied using Velocity Map Imaging (VMI) technique. Correlations among the transition dipole moment of the parent molecule, recoil velocity vector and rotational angular momentum vector of the photofragments were extracted from the anisotropic angular distributions of the images. The vector correlations extracted indicated a picture of photodissociation mainly via the excited 21A' (A) state. The transition dipole moment lies in the bending molecular plane, and the j⃑ is pointing perpendicular to the plane, while the μ-v vectors angle is between 41°-45°. In addition, a clear trend was observed. As the product CO rotational state j increases, the spatial anisotropy parameter (β ≡ 2β20(20)) decreases. This j-dependent attenuation of spatial anisotropy parameter can be explained mainly with the consideration of non-axial recoil effect. These results are in good agreement with both theoretical work and previous experimental work.
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Affiliation(s)
- Evangelia Sakkoula
- Institute for Molecules and Materials, Radboud University Nijmegen, Nijmegen, The Netherlands.
| | - Gautam Sharma
- Institute for Molecules and Materials, Radboud University Nijmegen, Nijmegen, The Netherlands.
| | - Xingan Wang
- Department of Chemical Physics, University of Science and Technology, Hefei 230026, China
| | - Simon W North
- Department of Chemistry, Texas A&M University, College Station, Texas, USA
| | - David H Parker
- Institute for Molecules and Materials, Radboud University Nijmegen, Nijmegen, The Netherlands.
| | - Wei Wei
- Department of Chemistry and Physics, Franklin College, Franklin, Indiana, USA.
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Zhou J, Luo Z, Yang J, Chang Y, Zhang Z, Yu Y, Li Q, Cheng G, Chen Z, He Z, Che L, Yu S, Wu G, Yuan K, Yang X. State-to-state photodissociation dynamics of CO 2 around 108 nm: the O( 1S) atom channel. Phys Chem Chem Phys 2020; 22:6260-6265. [PMID: 32129384 DOI: 10.1039/c9cp06919d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
State-to-state photodissociation of carbon dioxide (CO2) via the 3p1Πu Rydberg state was investigated by the time-sliced velocity map ion imaging technique (TSVMI) using a tunable vacuum ultraviolet free electron laser (VUV FEL) source. Raw images of the O(1S) products resulting from the O(1S) + CO(X1Σ+) channel were acquired at the photolysis wavelengths between 107.37 and 108.84 nm. From the vibrational resolved O(1S) images, the product total kinetic energy releases and the vibrational state distributions of the CO(X1Σ+) co-products were obtained, respectively. It is found that vibrationally excited CO co-products populate at as high as v = 6 or 7 while peaking at v = 1 and v = 4, and most of the individual vibrational peaks present a bimodal rotational structure. Furthermore, the angular distributions at all studied photolysis wavelengths have also been determined. The associated vibrational-state specific anisotropy parameters (β) exhibit a photolysis wavelength-dependent feature, in which the β-values observed at 108.01 nm and 108.27 nm are more positive than those at 107.37 nm and 107.52 nm, while the β-values have almost isotropic behaviour at 108.84 nm. These experimental results indicate that the initially prepared CO2 molecules around 108 nm should decay to the 41A' state via non-adiabatic coupling, and dissociate in the 41A' state to produce O(1S) + CO(X1Σ+) products with different dissociation time scales.
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Affiliation(s)
- Jiami Zhou
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou, Zhejiang 311231, China. and State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
| | - Zijie Luo
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China. and Department of Physics, School of Science, Dalian Maritime University, 1 Linghai Road, Dalian, Liaoning 116026, P. R. China
| | - Jiayue Yang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
| | - Yao Chang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
| | - Zhiguo Zhang
- Key Laboratory of Functional Materials and Devices for Informatics of Anhui Higher Education Institutions and School of Physics and Electronic Engineering, Fuyang Normal University, Fuyang, Anhui 236041, China.
| | - Yong Yu
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
| | - Qinming Li
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
| | - Gongkui Cheng
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
| | - Zhichao Chen
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
| | - Zhigang He
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
| | - Li Che
- Department of Physics, School of Science, Dalian Maritime University, 1 Linghai Road, Dalian, Liaoning 116026, P. R. China
| | - Shengrui Yu
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou, Zhejiang 311231, China.
| | - Guorong Wu
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
| | - Kaijun Yuan
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
| | - Xueming Yang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
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Chang YC, Liu K, Kalogerakis KS, Ng CY, Jackson WM. Branching Ratios of the N( 2D 03/2) and N( 2D 05/2) Spin-Orbit States Produced in the State-Selected Photodissociation of N 2 Determined Using Time-Sliced Velocity-Mapped-Imaging Photoionization Mass Spectrometry (TS-VMI-PI-MS). J Phys Chem A 2019; 123:2289-2300. [PMID: 30628443 DOI: 10.1021/acs.jpca.8b11691] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Branching ratios for N(2D03/2) and N(2D05/2) produced by predissociation of state selected excited nitrogen molecules in the vacuum ultraviolet region have been measured for the first time. The quantum numbers of the excited nitrogen molecule are defined by selective excitation of the nitrogen molecule in the Franck-Condon region from the ground electronic, 1Σg+, vibrational, v″, and rotational, J″ state to an excited Eu', v', J' state with a tunable vacuum ultraviolet, VUV1, laser. The neutral atoms produced by predissociation from this excited state are then selectively ionized with a second tunable VUV2 laser. Measurement of the relative populations of these two atoms formed in their spin-orbit states defines the quantum states for the atomic products. This means that the wave functions of the initial state and knowledge of the relative yields define all the experimental parameters for this series of unimolecular reactions. The ions formed by VUV2 are mass analyzed with a time-of-flight mass spectrometer and detected with a time slice velocity ion imaging mass spectrometer. In this manner, we can determine the recoil velocity associated with the predissociation process. Two different techniques are used to determine the spin-orbit ratios, namely, resonant VUV photoionization (RVUV-PI) spectroscopy and total kinetic energy release (TKER) spectroscopy determined from the image produced when the atoms are selectively ionized by VUV2 in the interaction region. The TKER spectra obtained from the lines at 110 296.25 and 110 304.96 cm-1 that couple to a newly discovered autoionization line at 129 529.4255 ± 0.0015 cm-1 prove that the lines observed in this region originate from the N(2D03/2) and N(2D05/2) atoms. Two other lines in this region at 110 286.20 and 110 299.89 cm-1 originate from the nitrogen N(4S03/2) that is photoionized in a 1+ 1 VUV-UV resonant multiphoton ionization process. The spin-orbit branching ratios have been evaluated for valence and Rydberg electronic excited states from 104 129.4 to 118 772.1 cm-1, and it shows that they are independent of the rotational and vibrational quantum numbers. They are not appreciably affected by the symmetry properties of the wave function in the Franck-Condon region of the excited states. In the energy region below 117 153.8 cm-1 the pathways at long internuclear distances appear to determine [N(2D03/2)]/[N(2D05/2)] branching ratios of ∼0.38, ∼0.62, and ∼1.04. At higher energies, TKER and RVUV-PI spectroscopy have been used to show that the average fraction of the N(2D03/2) and N(2D05/2) atoms produced in the spin-allowed channels that produce two N(2D0J) is 0.85 versus 0.15 for spin-forbidden channels. The importance and need for this information for comparison with theory and applications in astrochemistry are briefly discussed.
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Affiliation(s)
- Yih Chung Chang
- Department of Chemistry , University of California , Davis , California 95616 , United States
| | - Kai Liu
- Wuhan Institute of Physics and Mathematics, CAS , Wuhan 430071 , China
| | | | - Cheuk-Yiu Ng
- Department of Chemistry , University of California , Davis , California 95616 , United States
| | - William M Jackson
- Department of Chemistry , University of California , Davis , California 95616 , United States
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6
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Suits AG. Invited Review Article: Photofragment imaging. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:111101. [PMID: 30501356 DOI: 10.1063/1.5045325] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 10/25/2018] [Indexed: 06/09/2023]
Abstract
Photodissociation studies in molecular beams that employ position-sensitive particle detection to map product recoil velocities emerged thirty years ago and continue to evolve with new laser and detector technologies. These powerful methods allow application of tunable laser detection of single product quantum states, simultaneous measurement of velocity and angular momentum polarization, measurement of joint product state distributions for the detected and undetected products, coincident detection of multiple product channels, and application to radicals and ions as well as closed-shell molecules. These studies have permitted deep investigation of photochemical dynamics for a broad range of systems, revealed new reaction mechanisms, and addressed problems of practical importance in atmospheric, combustion, and interstellar chemistry. This review presents an historical overview, a detailed technical account of the range of methods employed, and selected experimental highlights illustrating the capabilities of the method.
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Affiliation(s)
- Arthur G Suits
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, USA
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Branching Ratios in Vacuum Ultraviolet Photodissociation of CO and N2: Implications for Oxygen and Nitrogen Isotopic Compositions of the Solar Nebula. ACTA ACUST UNITED AC 2017. [DOI: 10.3847/1538-4357/aa8ee7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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8
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Sutradhar S, Samanta BR, Samanta AK, Reisler H. Temperature dependence of the photodissociation of CO 2 from high vibrational levels: 205-230 nm imaging studies of CO(X 1Σ +) and O( 3P, 1D) products. J Chem Phys 2017; 147:013916. [PMID: 28688402 DOI: 10.1063/1.4979952] [Citation(s) in RCA: 3] [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 205-230 nm photodissociation of vibrationally excited CO2 at temperatures up to 1800 K was studied using Resonance Enhanced Multiphoton Ionization (REMPI) and time-sliced Velocity Map Imaging (VMI). CO2 molecules seeded in He were heated in an SiC tube attached to a pulsed valve and supersonically expanded to create a molecular beam of rotationally cooled but vibrationally hot CO2. Photodissociation was observed from vibrationally excited CO2 with internal energies up to about 20 000 cm-1, and CO(X1Σ+), O(3P), and O(1D) products were detected by REMPI. The large enhancement in the absorption cross section with increasing CO2 vibrational excitation made this investigation feasible. The internal energies of heated CO2 molecules that absorbed 230 nm radiation were estimated from the kinetic energy release (KER) distributions of CO(X1Σ+) products in v″ = 0. At 230 nm, CO2 needs to have at least 4000 cm-1 of rovibrational energy to absorb the UV radiation and produce CO(X1Σ+) + O(3P). CO2 internal energies in excess of 16 000 cm-1 were confirmed by observing O(1D) products. It is likely that initial absorption from levels with high bending excitation accesses both the A1B2 and B1A2 states, explaining the nearly isotropic angular distributions of the products. CO(X1Σ+) product internal energies were estimated from REMPI spectroscopy, and the KER distributions of the CO(X1Σ+), O(3P), and O(1D) products were obtained by VMI. The CO product internal energy distributions change with increasing CO2 temperature, suggesting that more than one dynamical pathway is involved when the internal energy of CO2 (and the corresponding available energy) increases. The KER distributions of O(1D) and O(3P) show broad internal energy distributions in the CO(X1Σ+) cofragment, extending up to the maximum allowed by energy but peaking at low KER values. Although not all the observations can be explained at this time, with the aid of available theoretical studies of CO2 VUV photodissociation and O + CO recombination, it is proposed that following UV absorption, the two lowest lying triplet states, a3B2 and b3A2, and the ground electronic state are involved in the dynamical pathways that lead to product formation.
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Affiliation(s)
- S Sutradhar
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, USA
| | - B R Samanta
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, USA
| | - A K Samanta
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, USA
| | - H Reisler
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, USA
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Lee C, Lin YC, Lee SH, Lee YY, Tseng CM, Lee YT, Ni CK. Advantage of spatial map ion imaging in the study of large molecule photodissociation. J Chem Phys 2017; 147:013904. [DOI: 10.1063/1.4975671] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Chin Lee
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Yen-Cheng Lin
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Shih-Huang Lee
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Yin-Yu Lee
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Chien-Ming Tseng
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Yuan-Tseh Lee
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Chi-Kung Ni
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
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10
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Poullain SM, Chicharro DV, Rubio-Lago L, García-Vela A, Bañares L. A velocity-map imaging study of methyl non-resonant multiphoton ionization from the photodissociation of CH 3I in the A-band. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2017; 375:rsta.2016.0205. [PMID: 28320907 PMCID: PMC5360903 DOI: 10.1098/rsta.2016.0205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/17/2016] [Indexed: 06/06/2023]
Abstract
Chemical reaction dynamics and, particularly, photodissociation in the gas phase are generally studied using pump-probe schemes where a first laser pulse induces the process under study and a second one detects the produced fragments. Providing an efficient detection of ro-vibrationally state-selected photofragments, the resonance enhanced multiphoton ionization (REMPI) technique is, without question, the most popular approach used for the probe step, while non-resonant multiphoton ionization (NRMPI) detection of the products is scarce. The main goal of this work is to test the sensitivity of the NRMPI technique to fragment vibrational distributions arising from molecular photodissociation processes. We revisit the well-known process of methyl iodide photodissociation in the A-band at around 280 nm, using the velocity-map imaging technique in conjunction with NRMPI of the methyl fragment. The detection wavelength, carefully selected to avoid any REMPI transition, was scanned between 325 and 335 nm seeking correlations between the different observables-the product vibrational, translational and angular distributions-and the excitation wavelength of the probe laser pulse. The experimental results have been discussed on the base of quantum dynamics calculations of photofragment vibrational populations carried out on available ab initio potential-energy surfaces using a four-dimensional model.This article is part of the themed issue 'Theoretical and computational studies of non-equilibrium and non-statistical dynamics in the gas phase, in the condensed phase and at interfaces'.
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Affiliation(s)
- Sonia Marggi Poullain
- Departamento de Química Física I (Unidad Asociada de I+D+I al CSIC), Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - David V Chicharro
- Departamento de Química Física I (Unidad Asociada de I+D+I al CSIC), Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Luis Rubio-Lago
- Departamento de Química Física I (Unidad Asociada de I+D+I al CSIC), Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | | | - Luis Bañares
- Departamento de Química Física I (Unidad Asociada de I+D+I al CSIC), Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
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11
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Heays A, Lewis B, Gibson S, Stark G, de Oliveira N. Indirect predissociation of highly excited singlet states of N 2. EPJ WEB OF CONFERENCES 2015. [DOI: 10.1051/epjconf/20158403004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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12
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Gardiner SH, Lipciuc ML, Karsili TNV, Ashfold MNR, Vallance C. Dynamics of the A-band ultraviolet photodissociation of methyl iodide and ethyl iodide via velocity-map imaging with ‘universal’ detection. Phys Chem Chem Phys 2015; 17:4096-106. [DOI: 10.1039/c4cp04654d] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Universal ionization combined with velocity-map imaging allows a comprehensive investigation into the photodissociation dynamics of methyl iodide and ethyl iodide at a range of UV wavelengths within their A-bands.
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Affiliation(s)
- Sara H. Gardiner
- Department of Chemistry
- University of Oxford
- Chemistry Research Laboratory
- Oxford
- UK
| | - M. Laura Lipciuc
- Department of Chemistry
- University of Oxford
- Chemistry Research Laboratory
- Oxford
- UK
| | | | | | - Claire Vallance
- Department of Chemistry
- University of Oxford
- Chemistry Research Laboratory
- Oxford
- UK
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13
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Lu Z, Chang YC, Benitez Y, Luo Z, Houria AB, Ayari T, Al Mogren MM, Hochlaf M, Jackson WM, Ng CY. State-to-state vacuum ultraviolet photodissociation study of CO2 on the formation of state-correlated CO(X1Σ+; v) with O(1D) and O(1S) photoproducts at 11.95–12.22 eV. Phys Chem Chem Phys 2015; 17:11752-62. [PMID: 25868654 DOI: 10.1039/c5cp01321f] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The state-to-state photodissociation of CO2 is investigated in the VUV range of 11.94–12.20 eV.
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Affiliation(s)
- Zhou Lu
- Department of Chemistry
- University of California
- Davis
- USA
| | | | | | - Zhihong Luo
- Department of Chemistry
- University of California
- Davis
- USA
| | - Adel Ben Houria
- Laboratoire de Spectroscopie Atomique
- Moléculaire et Applications – LSAMA
- Université de Tunis El Manar
- Tunis
- Tunisia
| | - Tarek Ayari
- Laboratoire de Spectroscopie Atomique
- Moléculaire et Applications – LSAMA
- Université de Tunis El Manar
- Tunis
- Tunisia
| | | | - M. Hochlaf
- Université Paris-Est
- Laboratoire Modélisation et Simulation Multi Echelle
- MSME UMR 8208 CNRS
- 77454 Marne-la-Vallée
- France
| | - W. M. Jackson
- Department of Chemistry
- University of California
- Davis
- USA
| | - C. Y. Ng
- Department of Chemistry
- University of California
- Davis
- USA
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14
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Lu Z, Chang YC, Yin QZ, Ng CY, Jackson WM. Photochemistry. Evidence for direct molecular oxygen production in CO₂ photodissociation. Science 2014; 346:61-4. [PMID: 25278605 DOI: 10.1126/science.1257156] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Photodissociation of carbon dioxide (CO2) has long been assumed to proceed exclusively to carbon monoxide (CO) and oxygen atom (O) primary products. However, recent theoretical calculations suggested that an exit channel to produce C + O2 should also be energetically accessible. Here we report the direct experimental evidence for the C + O2 channel in CO2 photodissociation near the energetic threshold of the C((3)P) + O2(X(3)Σ(g)(-)) channel with a yield of 5 ± 2% using vacuum ultraviolet laser pump-probe spectroscopy and velocity-map imaging detection of the C((3)PJ) product between 101.5 and 107.2 nanometers. Our results may have implications for nonbiological oxygen production in CO2-heavy atmospheres.
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Affiliation(s)
- Zhou Lu
- Department of Chemistry, University of California, Davis, CA 95616, USA
| | - Yih Chung Chang
- Department of Chemistry, University of California, Davis, CA 95616, USA
| | - Qing-Zhu Yin
- Department of Earth and Planetary Sciences, University of California, Davis, CA 95616, USA
| | - C Y Ng
- Department of Chemistry, University of California, Davis, CA 95616, USA.
| | - William M Jackson
- Department of Chemistry, University of California, Davis, CA 95616, USA.
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15
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Lu Z, Chang YC, Gao H, Benitez Y, Song Y, Ng CY, Jackson WM. Communication: direct measurements of nascent O((3)P0,1,2) fine-structure distributions and branching ratios of correlated spin-orbit resolved product channels CO(ã(3)Π; v) + O((3)P0,1,2) and CO(X̃(1)Σ(+); v) + O((3)P0,1,2) in VUV photodissociation of CO2. J Chem Phys 2014; 140:231101. [PMID: 24952514 DOI: 10.1063/1.4883515] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We present a generally applicable experimental method for the direct measurement of nascent spin-orbit state distributions of atomic photofragments based on the detection of vacuum ultraviolet (VUV)-excited autoionizing-Rydberg (VUV-EAR) states. The incorporation of this VUV-EAR method in the application of the newly established VUV-VUV laser velocity-map-imaging-photoion (VMI-PI) apparatus has made possible the branching ratio measurement for correlated spin-orbit state resolved product channels, CO(ã(3)Π; v) + O((3)P0,1,2) and CO(X̃(1)Σ(+); v) + O((3)P0,1,2), formed by VUV photoexcitation of CO2 to the 4s(10 (1)) Rydberg state at 97,955.7 cm(-1). The total kinetic energy release (TKER) spectra obtained from the O(+) VMI-PI images of O((3)P0,1,2) reveal the formation of correlated CO(ã(3)Π; v = 0-2) with well-resolved v = 0-2 vibrational bands. This observation shows that the dissociation of CO2 to form the spin-allowed CO(ã(3)Π; v = 0-2) + O((3)P0,1,2) channel has no potential energy barrier. The TKER spectra for the spin-forbidden CO(X̃(1)Σ(+); v) + O((3)P0,1,2) channel were found to exhibit broad profiles, indicative of the formation of a broad range of rovibrational states of CO(X̃(1)Σ(+)) with significant vibrational populations for v = 18-26. While the VMI-PI images for the CO(ã(3)Π; v = 0-2) + O((3)P0,1,2) channel are anisotropic, indicating that the predissociation of CO2 4s(10 (1)) occurs via a near linear configuration in a time scale shorter than the rotational period, the angular distributions for the CO(X̃(1)Σ(+); v) + O((3)P0,1,2) channel are close to isotropic, revealing a slower predissociation process, which possibly occurs on a triplet surface via an intersystem crossing mechanism.
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Affiliation(s)
- Zhou Lu
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
| | - Yih Chung Chang
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
| | - Hong Gao
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
| | - Yanice Benitez
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
| | - Yu Song
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
| | - C Y Ng
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
| | - W M Jackson
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
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16
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Ng CY. State-to-State Spectroscopy and Dynamics of Ions and Neutrals by Photoionization and Photoelectron Methods. Annu Rev Phys Chem 2014; 65:197-224. [DOI: 10.1146/annurev-physchem-040412-110002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Cheuk-Yiu Ng
- Department of Chemistry, University of California, Davis, California 95616;
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17
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Fillion JH, Fayolle EC, Michaut X, Doronin M, Philippe L, Rakovsky J, Romanzin C, Champion N, Öberg KI, Linnartz H, Bertin M. Wavelength resolved UV photodesorption and photochemistry of CO2ice. Faraday Discuss 2014; 168:533-52. [DOI: 10.1039/c3fd00129f] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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18
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Song Y, Gao H, Chang YC, Lu Z, Ng CY, Jackson WM. Photodissociation of CO2between 13.540 eV and 13.678 eV. Phys Chem Chem Phys 2014; 16:563-9. [DOI: 10.1039/c3cp53250j] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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19
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Gao H, Song Y, Chang YC, Shi X, Yin QZ, Wiens RC, Jackson WM, Ng CY. Branching ratio measurements for vacuum ultraviolet photodissociation of 12C16O. J Phys Chem A 2013; 117:6185-95. [PMID: 23510317 DOI: 10.1021/jp400412n] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The branching ratios for the spin-forbidden photodissociation channels of (12)C(16)O in the vacuum ultraviolet (VUV) photon energy region from 102,500 (12.709 eV) to 106,300 cm(-1) (13.180 eV) have been investigated using the VUV laser time-slice velocity-map imaging photoion technique. The excitations to three (1)Σ(+) and six (1)Π Rydberg-type states, including the progression of W(3sσ) (1)Π(v' = 0, 1, and 2) vibrational levels of CO, have been identified and investigated. The branching ratios for the product channels C((3)P) + O((3)P), C((1)D) + O((3)P), and C((3)P) + O((1)D) of these predissociative states are found to depend on the electronic, vibrational, and rotational states of CO being excited. Rotation and e/f-symmetry dependences of the branching ratios into the spin-forbidden channels have been confirmed for several of the (1)Π states, which can be explained using the heterogeneous interaction with the repulsive D'(1)Σ(+) state. The percentage of the photodissociation into the spin-forbidden channels is found to increase with increasing the rotational quantum number for the K(4pσ) (1)Σ(+) (v' = 0) state. This has been rationalized using a (1)Σ(+) to (1)Π to (3)Π coupling scheme, where the final (3)Π state is a repulsive valence state correlating to the spin-forbidden channel.
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Affiliation(s)
- Hong Gao
- Department of Chemistry, University of California, Davis, California 95616, USA
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20
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Gao H, Song Y, Jackson WM, Ng CY. Communication: State-to-state photodissociation study by the two-color VUV-VUV laser pump-probe time-slice velocity-map-imaging-photoion method. J Chem Phys 2013; 138:191102. [DOI: 10.1063/1.4807302] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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21
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Gao H, Song Y, Yang L, Shi X, Yin QZ, Ng CY, Jackson WM. Branching ratio measurements of the predissociation of 12C16O by time-slice velocity-map ion imaging in the energy region from 108,000 to 110,500 cm(-1). J Chem Phys 2012; 137:034305. [PMID: 22830700 DOI: 10.1063/1.4734018] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Direct branching ratio measurements of the three lowest dissociation channels of (12)C(16)O that produce C((3)P) + O((3)P), C((1)D) + O((3)P), and C((3)P) + O((1)D) are reported in the vacuum ultraviolet region from 108,000 cm(-1) (92.59 nm) to 110,500 cm(-1) (90.50 nm) using the time-slice velocity-map ion imaging and nonlinear resonant four-wave mixing techniques. Rotationally, resolved carbon ion yield spectra for both (1)Σ(+) and (1)Π bands of CO in this region have been obtained. Our measurements using this technique show that the branching ratio in this energy region, especially the relative percentages of the two spin-forbidden channels, is strongly dependent on the particular electronic and vibrational energy levels of CO that are excited.
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Affiliation(s)
- Hong Gao
- Department of Chemistry, University of California Davis, Davis, California 95616, USA
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22
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Gao H, Pan Y, Yang L, Zhou J, Ng CY, Jackson WM. Time-slice velocity-map ion imaging studies of the photodissociation of NO in the vacuum ultraviolet region. J Chem Phys 2012; 136:134302. [DOI: 10.1063/1.3696897] [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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23
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Gao H, Xu Y, Yang L, Lam CS, Wang H, Zhou J, Ng CY. High-resolution threshold photoelectron study of the propargyl radical by the vacuum ultraviolet laser velocity-map imaging method. J Chem Phys 2011; 135:224304. [DOI: 10.1063/1.3664864] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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24
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Gao H, Song Y, Yang L, Shi X, Yin Q, Ng CY, Jackson WM. Communication: branching ratio measurements in the predissociation of 12C16O by time-slice velocity-map ion imaging in the vacuum ultraviolet region. J Chem Phys 2011; 135:221101. [PMID: 22168673 DOI: 10.1063/1.3669426] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The first direct branching ratio measurement of the three lowest energy dissociation channels of CO that produce C((3)P) + O((3)P), C((1)D) + O((3)P), and C((3)P) + O((1)D) is reported. Rotational resolved carbon ion yield spectra for two Π bands (W(3sσ)(1)Π (v(') = 3) at 108,012.6 cm(-1) and (1)Π(v(') = 2) at 109,017 cm(-1)) and two Σ bands ((4sσ)(1)Σ(+)(v(') = 4) at 109,452 cm(-1) and (4pσ)(1)Σ(+)(v(') = 3) at 109,485 cm(-1)) of CO were obtained. Our measurements show that the branching ratio in this energy region is strongly dependent on the electronic and vibrational energy but it is independent or just weakly dependent on the parity and rotational energy levels. To our knowledge, this is the first time that the triplet channel producing O((1)D) has been experimentally observed and this is also the first time that a direct measurement of the branching ratio for the different channels in the predissociation of CO in this energy region has been made.
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Affiliation(s)
- Hong Gao
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
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25
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Gao H, Yang L, Pan Y, Zhou J, Ng CY, Jackson WM. Time-sliced velocity-mapped imaging studies of the predissociation of single ro-vibronic energy levels of N2 in the extreme ultraviolet region using vacuum ultraviolet photoionization. J Chem Phys 2011; 135:134319. [PMID: 21992317 DOI: 10.1063/1.3644778] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The predissociation of N(2) from the rotational levels in the o(1)∏(u) (v(') = 2) and b(') (1)Σ(u) (v(') = 8) bands has been studied in the wavenumber (or energy) range from 109 350 cm(-1) (13.5577 eV) to 109 580 cm(-1) (13.5862 eV) by time-sliced velocity-mapped imaging technique with VUV photoionization detection of the fragments. These levels were excited from the ground state of N(2) (X(1)Σ(g) (+), v(") = 0) levels using an unfocused vacuum ultraviolet (VUV) laser via a one-photon process. The same VUV laser is used to ionize the metastable N ((2)D(o)) produced from the predissociation process and the time-sliced velocity-mapped imaging technique is used to determine their velocity and angular distributions. Two different theoretical methods developed, respectively, by Kim et al. [J. Chem. Phys. 125, 133316 (2006) and Zande [J. Chem. Phys. 107, 9447 (1997)] were used to calculate the anisotropic parameters for the predissociation to the channel N((4)S(o)) + N((2)D(o)) to compare with the observed value for each of the rotational levels. Very good agreement with the experimental results was obtained for both methods. Possible predissociation mechanisms were predicted from the measurements and calculations.
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Affiliation(s)
- Hong Gao
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
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