The Reaction of the Methylidyne Radical (CH X2Π) with the Hydrogen Cyanide (HCN X1∑+) Molecule in Cold Molecular Clouds and Planetary Atmospheres

Lubov I. Krikunova orcid (Login required)
Lebedev Physical Institute, Samara, Russia
Samara National Research University, Russia

Anatoliy A. Nikolayev
Lebedev Physical Institute, Samara, Russia
Samara National Research University, Russia

Denis P. Porfirev
Lebedev Physical Institute, Samara, Russia
Samara National Research University, Russia

Alexander M. Mebel
Department of Chemistry and Biochemistry, Florida International University, Miami, Florida, USA


Paper #3476 received 19 Feb 2022; revised manuscript received 03 Apr 2022; accepted for publication 03 Apr 2022; published online 28 Apr 2022.

DOI: 10.18287/JBPE22.08.020301

Abstract

The reaction of the methylidyne (CH; X2Π) radical with hydrogen cyanide (HCN; X1∑) molecule was studied at a collision energy of 4.0 kJ/mol with ab initio calculations of the potential energy surface (PES). Geometries and potential energies of reactants, products, intermediates and transition states (TS) for the reaction were found by means of ab initio quantum chemical method ωB97xd/cc-pVTZ and the higher-level corrections were evaluated at the CCSD(T)-F12 level of theory with the cc-pVQZ-f12 (E1) and cc-pVTZ-f12 (E2) basis sets. The calculated values then were used for extrapolation to the complete basis set (CBS) limit using the two-point expression E(CBS) = E1 + 0.69377 × (E1 – E2). Analysis of the found energies, structural and kinetic characteristics of the involved compounds allowed us to determine the reaction paths leading to the formation of linear and cyclic intermediates, as well as to the formation of atomic and molecular hydrogen. Those results were utilized in Rice−Ramsperger−Kassel−Marcus calculations of the product branching ratios at the zero pressure limit – common approach in modelling of the cold molecular clouds chemistry. Mechanism identified emphasizes importance of the CH+HCN reaction as an important supplier of the initial bricks for building heterocyclic hydrocarbons in extreme environments.

Keywords

potential energy surface; rate constants; density functional theory; methylidyne; hydrogen cyanide; cyanomethylidyne; cyanomethylene

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References


1. M. Ohishi, “Search for complex organic molecules in space,” Journal of Physics: Conference Series 728(5), 052002 (2016).

2. M. Nuevo, E. Sciamma-O'Brien, S. A. Sandford, F. Salama, C. K. Materese, and A. L. D. Kilcoyne, “The Titan haze simulation (THS) experiment on COSmIC. part III. XANES study of laboratory analogs of titan tholins,” Icarus 376, 114841 (2022).

3. C. Romanzin, “Methane photochemistry: A brief review in the frame of a new experimental program of Titan’s atmosphere simulations,” Advances in Space Research 36(2), 258–267 (2005).

4. H. Wiesemeyer, R. Güsten, K. M. Menten, C. A. Durán, T. Csengeri, A. M. Jacob, R. Simon, J. Stutzki, and F. Wyrowski, “Unveiling the chemistry of interstellar CH-Spectroscopy of the 2 THz N= 2←1 ground state line,” Astronomy & Astrophysics 612, A37 (2018).

5. D. Xu, D. Li, “CH as a molecular gas tracer and c-shock tracer across a molecular cloud boundary in Taurus,” The Astrophysical Journal 833(1), 90 (2016).

6. K. Sellgren, R. G. Smith, and T. Y. Brooke, “The 3.2 – 3.6 Micron Spectra of Monoceros R2/IRS-3 and Elias 16,” Astrophysical Journal 433, 179–186 (1994).

7. B. Larsson, R. Liseau, “Gas and dust in the star-forming region ρ Oph A – II. The gas in the PDR and in the dense cores,” Astronomy & Astrophysics 608, A133 (2017).

8. Y. C. Minh, H. B. Liu, and R. Galvan´-Madrid, “Сhemical diagnostics of the massive star cluster-forming cloud G33.92+0.11. I. CS, CH3OH, CH3N, OCS, H2S, SO2, and SiO,” Astrophysical Journal 824(2), 99 (2016).

9. O. Kochina, D. Wiebe, “Organic compounds in star forming regions,” Origins of Life and Evolution of the Biospheres 44(3), 169–174 (2014).

10. J. L. Neill, E. A. Bergin, D. C. Lis, P. Schilke, N. R. Crockett, C. Favre, M. Emprechtinger, C. Comito, S.-L. Qin, D. E. Anderson, A. M. Burkhardt, C. Jo-Hsin, B. J. Harris, S. D. Lord, B. A. McGuire, T. D. McNeill, R. R. Monje, T. G. Phillips, A. L. Steber, T. Vasyunina, and S. Yu, “Herschel observations of extraordinary sources: analysis of the full herschel/hifi molecular line survey of sagittarius B2(N),” The Astrophysical Journal 789(1), 8 (2014).

11. J.-C. Loison, “Rate constants and the H atom branching ratio of the reactions of the methylidyne CH(X2П) radical with C2H2, C2H4, C3H4 (methylacetylene and allene), C3H6 (propene) and C4H8 (trans-butene),” Physical Chemistry Chemical Physics 11(4), 655–664 (2009).

12. J. M. Ribeiro, “Reaction Mechanism and Product Branching Ratios of the CH + C3H6 Reaction: A Theoretical Study,” The Journal of Physical Chemistry A 120(11), 1800–1812 (2016).

13. J.-D. Chai, “Long-range corrected hybrid density functionals with damped atom–atom dispersion corrections,” Physical Chemistry Chemical Physics 10(44), 6615–6620 (2008).

14. J.-D. Chai, M. Head-Gordon, “Systematic optimization of long-range corrected hybrid density functionals,” Physics Chemical Journal 128(8), 084106 (2008).

15. T. H. Dunning, “Gaussian basis sets for use in correlated molecular calculations. I. The atoms boron through neon and hydrogen,” The Journal of Chemical Physics 90(2), 1007–1023 (1989).

16. T. B. Adler, “A simple and efficient CCSD(T)-F12 approximation,” The Journal of Chemical Physics 127(22), 221106 (2007).

17. G. Knizia, “Simplified CCSD(T)-F12 methods: Theory and benchmarks,” The Journal of Chemical Physics 130(5), 054104 (2009).

18. J. M. L. Martin, O. Uzan, “Basis Set Convergence in Secondrow Compounds. The Importance of Core Polarization Functions,” Chemical Physics Letters 282(1), 16−24 (1998).

19. J. Zhang, E. F. Valeev, “Prediction of Reaction Barriers and Thermochemical Properties with Explicitly Correlated Coupled-Cluster Methods: A Basis Set Assessment,” Journal of Chemical Theory and Computation 8(9), 3175–3186 (2012).

20. M. J. Frisch, G. W. Trucks, H. B. Schegel et al., Gaussian 09 Revision A.1, Gaussian Inc, Wallingford (CT), 66, 219 (2009). [https://gaussian.com].

21. H.-J. Werner, MOLPRO, Version 2010.1, A Package of Ab Initio Programs MOLPRO.NET, University of Cardiff, UK, 2010. [https://www.molpro.net/info/2015.1/doc/manual/index.html].

22. R. A. Marcus, “Unimolecular reactions, rates and quantum state distribution of products,” Philosophical Transactions of the Royal Society of London. Series A: Physical and Engineering Sciences 332(1625), 283–296 (1990).

23. P. J. Robinson, K. A. Holbrook, Unimolecular Reactions, Wiley, New York (1972).

24. C. He, L. Zhao, A. M. Thomas, A. N. Morozov, A. M. Mebel, and R. I. Kaiser, “Elucidating the Chemical Dynamics of the Elementary Reactions of the 1-Propynyl Radical (CH3CC; X2A1) with Methylacetylene (H3CCCH; X1A1) and Allene (H2CCCH2; X1A1),” The Journal of Physical Chemistry A 123(26), 5446–5462 (2019).

25. F. Zhang, P. Maksyutenko, and R. I. Kaiser, “Chemical dynamics of the CH (X2Π) + C2H4 (X1A1g), CH (X2Π) + C2D4 (X1A1g), and CD (X2Π) + C2H4 (X1A1g) reactions studied under single collision conditions,” Physical Chemistry Chemical Physics 14(2), 529–537 (2012).






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