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Liu Q, Li Z, Liu P, Yang X, Yu S. Resonance-state selective photodissociation dynamics of OCS + hv → CS(X1Σ+) + O(3Pj=2,1,0) via the 21Σ+ state. J Chem Phys 2023; 158:2888161. [PMID: 37139996 DOI: 10.1063/5.0150850] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 04/21/2023] [Indexed: 05/05/2023] Open
Abstract
Understanding vacuum ultraviolet photodissociation dynamics of Carbonyl sulfide (OCS) is of considerable importance in the study of atmospheric chemistry. Yet, photodissociation dynamics of the CS(X1Σ+) + O(3Pj=2,1,0) channels following excitation to the 21Σ+(ν1',1,0) state has not been clearly understood so far. Here, we investigate the O(3Pj=2,1,0) elimination dissociation processes in the resonance-state selective photodissociation of OCS between 147.24 and 156.48 nm by using the time-sliced velocity-mapped ion imaging technique. The total kinetic energy release spectra are found to exhibit highly structured profiles, indicative of the formation of a broad range of vibrational states of CS(1Σ+). The fitted CS(1Σ+) vibrational state distributions differ for the three 3Pj spin-orbit states, but a general trend of the inverted characteristics is observed. Additionally, the wavelength-dependent behaviors are also observed in the vibrational populations for CS(1Σ+, v). The CS(X1Σ+, v = 0) has a significantly strong population at several shorter wavelengths, and the most populated CS(X1Σ+, v) is gradually transferred to a higher vibrational state with the decrease in the photolysis wavelength. The measured overall β-values for the three 3Pj spin-orbit channels slightly increase and then abruptly decrease as the photolysis wavelength increases, while the vibrational dependences of β-values show an irregularly decreasing trend with increasing CS(1Σ+) vibrational excitation at all studied photolysis wavelengths. The comparison of the experimental observations for this titled channel and the S(3Pj) channel reveals that two different intersystem crossing mechanisms may be involved in the formation of the CS(X1Σ+) + O(3Pj=2,1,0) photoproducts via the 21Σ+ 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
| | - Zheng Li
- 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 and Dalian Coherent Light Source, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023, People's Republic of China
- Department of Chemistry, College of Science, Southern University of Science and Technology, 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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Li Z, Liao H, Yang W, Yang X, Yu S. Vacuum ultraviolet photodissociation of OCS via the 2 1Σ + state: the S( 1D 2) elimination channel. Phys Chem Chem Phys 2022; 24:17870-17878. [PMID: 35851633 DOI: 10.1039/d2cp02044k] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The photodissociation of OCS is necessary to model the primary photochemical processes of OCS in the global cycling of sulfur and interstellar photochemistry. Here, by combining the time-sliced velocity-map ion imaging technique with the single vacuum ultraviolet photon ionization method, we have studied the CO(1Σ+, v) + S(1D2) photoproduct channel from the OCS photodissociation via the eight different vibrational resonances ( = 1-8) in the 21Σ+(, 1, 0) ← X1Σ+(0, 0, 0) band. From the measured S(1D2) images, the wavelength-dependent CO(1Σ+, v) vibrational state populations have been obtained in the wavelength range of 142.98-154.37 nm. The majority of the CO(1Σ+, v) photoproducts are shown to abruptly populate from low vibrational states to high vibrational states as the photolysis wavelength decreases from 152.38 to 148.92 nm. The anisotropy parameters (β) for the CO(1Σ+, v) + S(1D2) channel have also been determined from the images of the S(1D2) photoproducts. It is found that the vibrational state-specific β-values present a similar decreasing trend with increasing CO vibrational excitation for all the eight vibrational resonances of OCS*(21Σ+). These observations indicate that there is a possibility that more than one non-adiabatic dissociation pathways with different dissociation lifetimes are involved in the formation of CO(1Σ+) + S(1D2) photoproducts from the initial vibronic levels of the 21Σ+ state to the final dissociative state.
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Affiliation(s)
- Zheng Li
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou, 311231, Zhejiang Province, P. R. China.
| | - Hong Liao
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou, 311231, Zhejiang Province, P. R. China.
| | - Wenshao Yang
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou, 311231, Zhejiang Province, P. R. China.
| | - Xueming Yang
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou, 311231, Zhejiang Province, P. R. China. .,State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, Liaoning Province, P. R. China.,Department of Chemistry, College of Science, Southern University of Science and Technology, 1088 Xueyuan Road, Shenzhen, 518055, P. R. China
| | - Shengrui Yu
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou, 311231, Zhejiang Province, P. R. China.
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Karamatskos ET, Yarlagadda S, Patchkovskii S, Vrakking MJJ, Welsch R, Küpper J, Rouzée A. Time-resolving the UV-initiated photodissociation dynamics of OCS. Faraday Discuss 2021; 228:413-431. [PMID: 33570531 DOI: 10.1039/d0fd00119h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We present a time-resolved study of the photodissociation dynamics of OCS after UV-photoexcitation at λ = 237 nm. OCS molecules (X1Σ+) were primarily excited to the 11A'' and the 21A' Renner-Teller components of the 1Σ- and 1Δ states. Dissociation into CO and S fragments was observed through time-delayed strong-field ionisation and imaging of the kinetic energy of the resulting CO+ and S+ fragments by intense 790 nm laser pulses. Surprisingly, fast oscillations with a period of ∼100 fs were observed in the S+ channel of the UV dissociation. Based on wavepacket-dynamics simulations coupled with a simple electrostatic-interaction model, these oscillations do not correspond to the known highly-excited rotational motion of the leaving CO(X1Σ+, J ≫ 0) fragments, which has a timescale of ∼140 fs. Instead, we suggest to assign the observed oscillations to the excitation of vibrational wavepackets in the 23A'' or 21A'' states of the molecule that predissociate to form S(3PJ) photoproducts.
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Affiliation(s)
- Evangelos T Karamatskos
- Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany. and Department of Physics, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | | | | | | | - Ralph Welsch
- Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany. and Center for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Jochen Küpper
- Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany. and Department of Physics, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany and Center for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Arnaud Rouzée
- Max Born Institute, Max-Born-Straße 2a, 12489 Berlin, Germany.
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Bai XL, Zhao DF, Chen Y. Photodissociation dynamics of OCS at 207 nm: S( 1D 2)+CO( X1Σ +) product channel. CHINESE J CHEM PHYS 2020. [DOI: 10.1063/1674-0068/cjcp1908148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Xi-lin Bai
- School of Physics and Information Engineering, Shanxi Normal University, Linfen 041004, China
| | - Dong-feng Zhao
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, and Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Yang Chen
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, and Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei 230026, China
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5
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Wallace CJ, Gunthardt CE, McBane GC, North SW. Empirical assignment of absorbing electronic state contributions to OCS photodissociation product state populations from 214 to 248 nm. Chem Phys 2019. [DOI: 10.1016/j.chemphys.2018.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Abstract
We show that the importance sampling technique can effectively augment the range of problems where the nuclear ensemble approach can be applied. A sampling probability distribution function initially determines the collection of initial conditions for which calculations are performed, as usual. Then, results for a distinct target distribution are computed by introducing compensating importance sampling weights for each sampled point. This mapping between the two probability distributions can be performed whenever they are both explicitly constructed. Perhaps most notably, this procedure allows for the computation of temperature dependent observables. As a test case, we investigated the UV absorption spectra of phenol, which has been shown to have a marked temperature dependence. Application of the proposed technique to a range that covers 500 K provides results that converge to those obtained with conventional sampling. We further show that an overall improved rate of convergence is obtained when sampling is performed at intermediate temperatures. The comparison between calculated and the available measured cross sections is very satisfactory, as the main features of the spectra are correctly reproduced. As a second test case, one of Tully's classical models was revisited, and we show that the computation of dynamical observables also profits from the importance sampling technique. In summary, the strategy developed here can be employed to assess the role of temperature for any property calculated within the nuclear ensemble method, with the same computational cost as doing so for a single temperature.
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Affiliation(s)
- Fábris Kossoski
- Instituto de Fı́sica "Gleb Wataghin" , Universidade Estadual de Campinas , 13083-859 Campinas , São Paulo , Brazil.,Aix Marseille Univ , CNRS, ICR , Marseille , France
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7
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Hao Q, Long J, Deng X, Tang Y, Abulimiti B, Zhang B. Superexcited State Dynamics of OCS: An Experimental Identification of Three Competing Decay Channels among Autoionization, Internal Conversion, and Neutral Predissociation. J Phys Chem A 2017; 121:3858-3863. [DOI: 10.1021/acs.jpca.7b01895] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Qiaoli Hao
- State
Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, PR China
- University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Jinyou Long
- State
Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, PR China
- University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Xulan Deng
- State
Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, PR China
- University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Ying Tang
- State
Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, PR China
- University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Bumaliya Abulimiti
- College
of Physics and Electronic Engineering, Xinjiang Normal University, Urumqi 830054, PR China
| | - Bing Zhang
- State
Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, PR China
- University of Chinese Academy of Sciences, Beijing 100049, PR China
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8
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Holland D, Shaw D. A study of the valence shell absolute photoabsorption, photoionisation and photodissociation cross sections and the photoionisation quantum efficiency of carbonyl sulphide. Chem Phys 2016. [DOI: 10.1016/j.chemphys.2016.10.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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9
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Toulson BW, Murray C. Decomposing the First Absorption Band of OCS Using Photofragment Excitation Spectroscopy. J Phys Chem A 2016; 120:6745-52. [PMID: 27552402 DOI: 10.1021/acs.jpca.6b06060] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Photofragment excitation spectra of carbonyl sulfide (OCS) have been recorded from 212-260 nm by state-selectively probing either electronically excited S((1)D) or ground state S((3)P) photolysis products via 2 + 1 resonance-enhanced multiphoton ionization. Probing the major S((1)D) product results in a broad, unstructured action spectrum that reproduces the overall shape of the first absorption band. In contrast, spectra obtained probing S((3)P) products display prominent resonances superimposed on a broad continuum; the resonances correspond to the diffuse vibrational structure observed in the conventional absorption spectrum. The vibrational structure is assigned to four progressions, each dominated by the C-S stretch, ν1, following direct excitation to quasi-bound singlet and triplet states. The S((3)PJ) products are formed with a near-statistical population distribution over the J = 2, 1, and 0 spin-orbit levels across the wavelength range investigated. Although a minor contributor to the S atom yield near the peak of the absorption cross section, the relative yield of S((3)P) increases significantly at longer wavelengths. The experimental measurements validate recent theoretical work characterizing the electronic states responsible for the first absorption band by Schmidt and co-workers.
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Affiliation(s)
- Benjamin W Toulson
- Department of Chemistry, University of California, Irvine , Irvine, California 92697, United States
| | - Craig Murray
- Department of Chemistry, University of California, Irvine , Irvine, California 92697, United States
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10
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Wei W, Wallace CJ, McBane GC, North SW. Photodissociation dynamics of OCS near 214 nm using ion imaging. J Chem Phys 2016; 145:024310. [PMID: 27421408 DOI: 10.1063/1.4955189] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The OCS photodissociation dynamics of the dominant S((1)D2) channel near 214 nm have been studied using velocity map ion imaging. We report a CO vibrational branching ratio of 0.79:0.21 for v = 0:v = 1, indicating substantially higher vibrational excitation than that observed at slightly longer wavelengths. The CO rotational distribution is bimodal for both v = 0 and v = 1, although the bimodality is less pronounced than at longer wavelengths. Vector correlations, including rotational alignment, indicate that absorption to both the 2(1)A' (A) and 1(1)A″ (B) states is important in the lower-j part of the rotational distribution, while only 2(1)A' state absorption contributes to the upper part; this conclusion is consistent with work at longer wavelengths. Classical trajectory calculations including surface hopping reproduce the measured CO rotational distributions and their dependence on wavelength well, though they underestimate the v = 1 population. The calculations indicate that the higher-j peak in the rotational distribution arises from molecules that begin on the 2(1)A' state but make nonadiabatic transitions to the 1(1)A' (X) state during the dissociation, while the lower-j peak arises from direct photodissociation on either the 2(1)A' or the 1(1)A″ states, as found in previous work.
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Affiliation(s)
- Wei Wei
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, USA
| | - Colin J Wallace
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, USA
| | - George C McBane
- Department of Chemistry, Grand Valley State University, Allendale, Michigan 49401, USA
| | - Simon W North
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, USA
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Nonadiabatic ab initio molecular dynamics of photoisomerization reaction between 1,3-cyclohexadiene and 1,3,5-cis-hexatriene. Chem Phys 2015. [DOI: 10.1016/j.chemphys.2015.07.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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12
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Schmidt JA, Olsen JMH. Photodissociation of OCS: Deviations between theory and experiment, and the importance of higher order correlation effects. J Chem Phys 2014; 141:184310. [DOI: 10.1063/1.4901426] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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Schmidt JA, Johnson MS, McBane GC, Schinke R. The ultraviolet spectrum of OCS from first principles: Electronic transitions, vibrational structure and temperature dependence. J Chem Phys 2012; 137:054313. [DOI: 10.1063/1.4739756] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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Schmidt JA, Johnson MS, McBane GC, Schinke R. Communication: Multi-state analysis of the OCS ultraviolet absorption including vibrational structure. J Chem Phys 2012; 136:131101. [PMID: 22482532 DOI: 10.1063/1.3701699] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- J A Schmidt
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark.
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Lipciuc ML, Rakitzis TP, Meerts WL, Groenenboom GC, Janssen MHM. Towards the complete experiment: measurement of S(1D2) polarization in correlation with single rotational states of CO(J) from the photodissociation of oriented OCS(v2 = 1|JlM = 111). Phys Chem Chem Phys 2011; 13:8549-59. [DOI: 10.1039/c0cp02671a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Geological sulfur isotopes indicate elevated OCS in the Archean atmosphere, solving faint young sun paradox. Proc Natl Acad Sci U S A 2009; 106:14784-9. [PMID: 19706450 DOI: 10.1073/pnas.0903518106] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Distributions of sulfur isotopes in geological samples would provide a record of atmospheric composition if the mechanism producing the isotope effects could be described quantitatively. We determined the UV absorption spectra of 32SO2, 33SO2, and 34SO2 and use them to interpret the geological record. The calculated isotopic fractionation factors for SO2 photolysis give mass independent distributions that are highly sensitive to the atmospheric concentrations of O2, O3, CO2, H2O, CS2, NH3, N2O, H2S, OCS, and SO2 itself. Various UV-shielding scenarios are considered and we conclude that the negative Delta33S observed in the Archean sulfate deposits can only be explained by OCS shielding. Of relevant Archean gases, OCS has the unique ability to prevent SO2 photolysis by sunlight at lambda >202 nm. Scenarios run using a photochemical box model show that ppm levels of OCS will accumulate in a CO-rich, reducing Archean atmosphere. The radiative forcing, due to this level of OCS, is able to resolve the faint young sun paradox. Further, the decline of atmospheric OCS may have caused the late Archean glaciation.
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