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Ahamed SS, Mahanta H, Paul AK. An advanced bath model to simulate association followed by ensuing dissociation dynamics of benzene + benzene system: a comparative study of gas and condensed phase results. Phys Chem Chem Phys 2022; 24:23825-23839. [PMID: 36164966 DOI: 10.1039/d2cp02483g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The role of the environment (N2 molecules) on the association followed by the ensuing dissociation reaction of benzene + benzene system is studied here with the help of a new code setup. Chemical dynamics simulations are performed to investigate this reaction in vacuum as well as in a bath of 1000 N2 molecules, equilibrated at 300 K. Bath densities of 20 and 324 kg m-3 are considered with a few results from the latter density. The simulations are performed at three different excitation temperatures of benzene, namely, 1000, 1500, and 2000 K, with an impact parameter range of 0-12 Å for both vacuum and bath models. Higher association probabilities and hence, higher temperature dependent association rate constants are obtained in the condensed phase. In the condensed phase, when a trajectory takes a longer time for the monomers to associate, the associated complex is formed with a longer lifetime and provides a lower rate of ensuing dissociation. Higher association rate and lower dissociation rate in condensed phase dynamics are due to the energy transfer process. Hence, the energy transfer phenomenon plays a decisive role in the association/dissociation dynamics, which is completely ignored in the same reaction when studied in vacuum.
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Affiliation(s)
- Sk Samir Ahamed
- Department of Chemistry, National Institute of Technology Meghalaya, Shillong 793003, Meghalaya, India.
| | - Himashree Mahanta
- Department of Chemistry, National Institute of Technology Meghalaya, Shillong 793003, Meghalaya, India.
| | - Amit K Paul
- Department of Chemistry, National Institute of Technology Meghalaya, Shillong 793003, Meghalaya, India.
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Ahamed SS, Kumar P, Kalita H, Paul AK. Mode‐to‐Mode Collision Energy Transfer from Vibrationally Excited C
6
F
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to NO/N
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Mixed Bath with the Development of New Potential Energy Functions. ChemistrySelect 2020. [DOI: 10.1002/slct.202002600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Sk. Samir Ahamed
- Department of Chemistry National Institute of Technology Meghalaya Shillong Meghalaya 793003 INDIA
| | - Pavan Kumar
- Department of Chemistry National Institute of Technology Meghalaya Shillong Meghalaya 793003 INDIA
| | - Hrishikesh Kalita
- Department of Chemistry National Institute of Technology Meghalaya Shillong Meghalaya 793003 INDIA
- Department of Chemistry Indian Institute of Technology Guwahati Guwahati Assam 781039 INDIA
| | - Amit K. Paul
- Department of Chemistry National Institute of Technology Meghalaya Shillong Meghalaya 793003 INDIA
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Ahamed SS, Mahanta H, Paul AK. A Competition between Dissociation Pathway and Energy Transfer Pathway: Unimolecular Dissociation of a Benzene-Hexafluorobenzene Complex in Nitrogen Bath. J Phys Chem A 2019; 123:10663-10675. [PMID: 31755713 DOI: 10.1021/acs.jpca.9b07258] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The unimolecular dissociation of a benzene-hexafluorobenzene complex at 1000, 1500, and 2000 K is studied inside a bath of 1000 N2 molecules kept at 300 K using chemical dynamics simulation. Three bath densities of 20, 324, and 750 kg/m3 are considered. The dissociation dynamics of the complex at a 20 kg/m3 bath density is found to be similar to that in the gas phase, whereas the dynamics is drastically different at higher bath densities. The microcanonical/canonical dissociation rate constants for the three bath densities are calculated and fitted to the Arrhenius equation. The activation energies are found to be similar to the gas-phase one. However, the pre-exponential factor is lower and decreases with the increase in bath density. The vibrational degree of freedom of the complex more effectively participates in the collisional energy transfer to the N2 bath, whereas the translational and rotational degrees of freedom of N2 receive the transferred energy. The energy transfer efficiency increases with the increase in bath density. The time scale of the energy transfer pathway is more than that of the dissociation pathway, and negligible direct dissociation of the complex is observed from the simulation at the highest bath density.
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Affiliation(s)
- Sk Samir Ahamed
- Department of Chemistry , National Institute of Technology Meghalaya , Shillong 793003 , Meghalaya , India
| | - Himashree Mahanta
- Department of Chemistry , National Institute of Technology Meghalaya , Shillong 793003 , Meghalaya , India
| | - Amit K Paul
- Department of Chemistry , National Institute of Technology Meghalaya , Shillong 793003 , Meghalaya , India
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Experiments on collisional energy transfer. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/b978-0-444-64207-3.00001-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Paul AK, West NA, Winner JD, Bowersox RDW, North SW, Hase WL. Non-statistical intermolecular energy transfer from vibrationally excited benzene in a mixed nitrogen-benzene bath. J Chem Phys 2018; 149:134101. [DOI: 10.1063/1.5043139] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Amit K. Paul
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, USA
- Department of Chemistry, National Institute of Technology Meghalaya, Shillong 793003, India
| | - Niclas A. West
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, USA
| | - Joshua D. Winner
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, USA
| | | | - Simon W. North
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, USA
| | - William L. Hase
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, USA
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Shen X, Wang S, Dai K, Shen Y. Nascent rotational distribution for LiH(v=0-3,J) states from collisions with H 2(E=4300 and 4800cm -1). SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2017; 173:516-526. [PMID: 27741492 DOI: 10.1016/j.saa.2016.09.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 08/28/2016] [Accepted: 09/26/2016] [Indexed: 06/06/2023]
Abstract
Rotationally state selective excitation of H2(v=1, J=1 or 3) was achieved by stimulated Raman pumping. The full state-resolved distribution of scattered LiH(v=0-3, J=0~13)molecules from collisions with excited H2(E=4300 and 4800cm-1) is reported. Nascent rotational and translational energy profiles for scattered LiH(v=0~3) molecules with J=0~13 were measured using high-resolution transient laser induced fluorescence(LIF). The product translational energy for individual J-states increases by 120% for a 13% increase in donor energy. The scattered LiH(v=0, J=0~13) molecules have a biexponential rotational distribution. Fitting the data with a two-component exponential model yields a low-energy distribution and a high-energy distribution. The rotational distribution is sensitive to donor energy. Rotational distributions of scatted LiH(v=1-3) molecules were also measured. The distribution yielded rotational temperatures at 690K for LiH/H2(E=4300cm-1) and 730K for LiH/H2(E=4800cm-1), respectively. The rate constants for appearance LiH(v=0-3,J) were determined.
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Affiliation(s)
- Xiaoyan Shen
- School of Chemistry and Molecular Engineering, East China University of Sci.&Tech., Shanghai, 200237, China
| | - Shuying Wang
- School of Physics, Xinjiang University, Urumqi, 830046, China
| | - Kang Dai
- School of Physics, Xinjiang University, Urumqi, 830046, China
| | - Yifan Shen
- School of Physics, Xinjiang University, Urumqi, 830046, China
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Bao JL, Truhlar DG. Variational transition state theory: theoretical framework and recent developments. Chem Soc Rev 2017; 46:7548-7596. [DOI: 10.1039/c7cs00602k] [Citation(s) in RCA: 207] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This article reviews the fundamentals of variational transition state theory (VTST), its recent theoretical development, and some modern applications.
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Affiliation(s)
- Junwei Lucas Bao
- Department of Chemistry
- Chemical Theory Center, and Minnesota Supercomputing Institute
- University of Minnesota
- Minneapolis
- USA
| | - Donald G. Truhlar
- Department of Chemistry
- Chemical Theory Center, and Minnesota Supercomputing Institute
- University of Minnesota
- Minneapolis
- USA
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Paul AK, Kohale SC, Pratihar S, Sun R, North SW, Hase WL. A unified model for simulating liquid and gas phase, intermolecular energy transfer: N2+ C6F6collisions. J Chem Phys 2014; 140:194103. [DOI: 10.1063/1.4875516] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Du J, Sassin NA, Havey DK, Hsu K, Mullin AS. Full State-Resolved Energy Gain Profiles of CO2 from Collisions with Highly Vibrationally Excited Molecules. II. Energy-Dependent Pyrazine (E = 32 700 and 37 900 cm–1) Relaxation. J Phys Chem A 2013; 117:12104-15. [DOI: 10.1021/jp404939s] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Juan Du
- Department of Chemistry & Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Nicholas A. Sassin
- Department of Chemistry & Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Daniel K. Havey
- Department of Chemistry & Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Kailin Hsu
- Department of Chemistry & Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Amy S. Mullin
- Department of Chemistry & Biochemistry, University of Maryland, College Park, Maryland 20742, United States
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Ree J, Kim SH, Lee SK. Energy Flow and Bond Dissociation of Vibrationally Excited Toluene in Collisions with N2and O2. B KOREAN CHEM SOC 2013. [DOI: 10.5012/bkcs.2013.34.5.1494] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Hsu HC, Tsai MT, Dyakov YA, Ni CK. Energy transfer of highly vibrationally excited molecules studied by crossed molecular beam/time-sliced velocity map ion imaging. INT REV PHYS CHEM 2012. [DOI: 10.1080/0144235x.2012.673282] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Strekalov M. Modeling transition probabilities with the multiexponential model using the real density of states. Chem Phys Lett 2010. [DOI: 10.1016/j.cplett.2010.01.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Ferguson HA, Parworth CL, Holloway TB, Midgett AG, Heard GL, Setser DW, Holmes BE. Characterization of the unimolecular water elimination reaction from 1-propanol, 3,3,3-propan-1-ol-d3, 3,3,3-trifluoropropan-1-ol, and 3-chloropropan-1-ol. J Phys Chem A 2009; 113:10013-23. [PMID: 19702256 DOI: 10.1021/jp905012r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The unimolecular reactions of 1-propanol, 3,3,3-propan-1-ol-d3, 3,3,3-trifluoropropan-1-ol, and 3-chloropropan-1-ol have been studied by the chemical activation technique. The recombination of CH3, CD3, CF3, and CH2Cl radicals with CH2CH2OH radicals at room temperature was used to generate vibrationally excited CH3CH2CH2OH, CD3CH2CH2OH, CF3CH2CH2OH, and CH2ClCH2CH2OH molecules. The principal unimolecular reaction for propanol and propanol-d3 with 90 kcal mol(-1) of vibrational energy is 1,2-H2O elimination with rate constants of 3.4 x 10(5) and 1.4 x 10(5) s(-1), respectively. For CH2ClCH2CH2OH also with 90 kcal mol(-1) of energy, 2,3-HCl elimination with a rate constant of 3.0 x 10(7) s(-1) is more important than 1,2-H2O elimination; the branching fractions are 0.95 and 0.05. For CF3CH2CH2OH with an energy of 102 kcal mol(-1), 1,2-H2O elimination has a rate constant of 7.9 x 10(5) and 2,3-HF elimination has a rate constant of 2.6 x 10(5) s(-1). Density functional theory was used to obtain models for the molecules and their transition states. The frequencies and moments of inertia from these models were used to calculate RRKM rate constants, which were used to assign threshold energies by comparing calculated and experimental rate constants. This comparison gives the threshold energy for H2O elimination from 1-propanol as 64 kcal mol(-1). The threshold energies for 1,2-H2O and 2,3-HCl elimination from CH2ClCH2CH2OH were 59 and 54 kcal mol(-1), respectively. The threshold energies for H2O and HF elimination from CF3CH2CH2OH are 62 and 70 kcal mol(-1), respectively. The structures of the transition states for elimination of HF, HCl, and H2O are compared.
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