For the past decades, the hydrogen-abstraction/acetylene-addition (HACA) mechanism has been instrumental in attempting to untangle the origin of polycyclic aromatic hydrocarbons (PAHs) as identified in carbonaceous meteorites such as Allende and Murchison. However, the fundamental reaction mechanisms leading to the synthesis of PAHs beyond phenanthrene (C14H10) are still unknown. By exploring the reaction of the 4-phenanthrenyl radical (C14H9•) with acetylene (C2H2) under conditions prevalent in carbon-rich circumstellar environments, we show evidence of a facile, isomer-selective formation of pyrene (C16H10). Along with the hydrogen-abstraction/vinylacetylene-addition (HAVA) mechanism, molecular mass growth processes from pyrene may lead through systematic ring expansions not only to more complex PAHs, but ultimately to 2D graphene-type structures. These fundamental reaction mechanisms are crucial to facilitate an understanding of the origin and evolution of the molecular universe and, in particular, of carbon in our Galaxy.
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Elsila, J. E., de Leon, N. P., Buseck, P. R. & Zare, R. N. Alkylation of polycyclic aromatic hydrocarbons in carbonaceous chondrites. Geochim. Cosmochim. Acta 69, 1349–1357 (2005).
D’Hendecourt, L. & Ehrenfreund, P. Spectroscopic properties of polycyclic aromatic hydrocarbons (PAHs) and astrophysical implications. Adv. Space Res. 19, 1023–1032 (1997).
Tielens, A. G. G. M., Kerckhoven, C., Peeters, E. & Hony, S. Interstaller and circumstellar PAHs. in Proc. IAU Symposium 197: Astrochemistry: from Molecular Clouds to Planetary Systems (eds Minh, Y. C & van Dishoeck, E. F.) 349–362 (2000).
Rhee, Y. M., Lee, T. J., Gudipati, M. S., Allamandola, L. J. & Head-Gordon, M. Charged polycyclic aromatic hydrocarbon clusters and the galactic extended red emission. Proc. Natl Acad. Sci. USA 104, 5274–5278 (2007).
Salama, F., Galazutdinov, G. A., Krelowski, J., Allamandola, L. J. & Musaev, F. A. Polycyclic aromatic hydrocarbons and the diffuse interstellar bands: a survey. Astrophys. J. 526, 265–273 (1999).
Duley, W. W. Polycyclic aromatic hydrocarbons, carbon nanoparticles and the diffuse interstellar bands. Faraday Discuss. 133, 415–425 (2006).
Ricks, A. M., Douberly, G. E. & Duncan, M. A. The infrared spectrum of protonated naphthalene and its relevance for the unidentified infrared bands. Astrophys. J. 702, 301–306 (2009).
Messenger, S. et al. Indigenous polycyclic aromatic hydrocarbons in circumstellar graphite grains from primitive meteorites. Astrophys. J. 502, 284–295 (1998).
Hahn, J. H., Zenobi, R., Bada, J. L. & Zare, R. N. Application of two-step laser mass spectrometry to cosmogeochemistry: direct analysis of meteorites. Science 239, 1523–1525 (1988).
Zenobi, R., Philippoz, J.-M., Buseck, P. R. & Zare, R. N. Spatially resolved organic analysis of the allende meteorite. Science 246, 1026–1029 (1989).
Plows, F. L., Elsila, J. E., Zare, R. N. & Buseck, P. R. Evidence that polycyclic aromatic hydrocarbons in two carbonaceous chondrites predate parent-body formation. Geochim. Cosmochim. Acta 67, 1429–1436 (2003).
Gilmour, I. & Pillinger, C. T. Isotopic compositions of individual polycyclic aromatic hydrocarbons from the murchison meteorite. Mon. Not. R. Astron. Soc. 269, 235–240 (1994).
Naraoka, H., Shimoyama, A. & Harada, K. Molecular and isotopic distributions of pahs from three antarctic carbonaceous chondrites (CM2). Mineral. Mag. 62A, 1056–1057 (1998).
Naraoka, H., Shimoyama, A. & Harada, K. Isotopic evidence from an antarctic carbonaceous chondrite for two reaction pathways of extraterrestrial PAH formation. Earth Planet. Sci. Lett. 184, 1–7 (2000).
Tielens, A. G. G. M. Interstellar polycyclic aromatic hydrocarbon molecules. Annu. Rev. Astron. Astr. 46, 289–337 (2008).
Tielens, A. G. G. M. The molecular universe. Rev. Mod. Phys. 85, 1021–1081 (2013).
Parker, D. S. et al. Low temperature formation of naphthalene and its role in the synthesis of pahs (polycyclic aromatic hydrocarbons) in the interstellar medium. Proc. Natl Acad. Sci. USA 109, 53–58 (2012).
Parker, D. S., Kaiser, R. I., Troy, T. P. & Ahmed, M. Hydrogen abstraction/acetylene addition revealed. Angew. Chem. Int. Edit. 53, 7740–7744 (2014).
Parker, D. S. N. et al. Unexpected chemistry from the reaction of naphthyl and acetylene at combustion-like temperatures. Angew. Chem. Int. Edit. 54, 5421–5424 (2015).
Yang, T. et al. HACA's heritage: a free-radical pathway to phenanthrene in circumstellar envelopes of asymptotic giant branch stars. Angew. Chem. Int. Edit. 56, 4515–4519 (2017).
Frenklach, M. & Feigelson, E. D. Formation of polycyclic aromatic hydrocarbons in circumstellar envelopes. Astrophys. J. 341, 372–384 (1989).
Richter, H. & Howard, J. B. Formation of polycyclic aromatic hydrocarbons and their growth to soot — a review of chemical reaction pathways. Prog. Energy Combust. Sci. 26, 565–608 (2000).
Frenklach, M. Reaction mechanism of soot formation in flames. Phys. Chem. Chem. Phys. 4, 2028–2037 (2002).
Frenklach, M., Clary, D. W., Gardiner, W. C. & Stein, S. E. Detailed kinetic modeling of soot formation in shock-tube pyrolysis of acetylene. Proc. Combust. Inst. 20, 887–901 (1985).
Wang, H. & Frenklach, M. Calculations of rate coefficients for the chemically activated reactions of acetylene with vinylic and aromatic radicals. J. Phys. Chem. 98, 11465–11489 (1994).
Appel, J., Bockhorn, H. & Frenklach, M. Kinetic modeling of soot formation with detailed chemistry and physics: laminar premixed flames of C2 hydrocarbons. Combust. Flame 121, 122–136 (2000).
Marsh, N. D. & Wornat, M. J. Formation pathways of ethynyl-substituted and cyclopentafused polycyclic aromatic hydrocarbons. Proc. Combust. Inst. 28, 2585–2592 (2000).
Tokmakov, I. V. & Lin, M. C. Reaction of phenyl radicals with acetylene: Quantum chemical investigation of the mechanism and master equation analysis of the kinetics. J. Am. Chem. Soc. 125, 11397–11408 (2003).
Kislov, V. V., Sadovnikov, A. I. & Mebel, A. M. Formation mechanism of polycyclic aromatic hydrocarbons beyond the second aromatic ring. J. Phys. Chem. A 117, 4794–4816 (2013).
Chmielewski, A. G. et al. NOx and PAHs removal from industrial flue gas by using electron beam technology with alcohol addition. Radiat. Phys. Chem. 67, 555–560 (2003).
Schuetz, C. A. & Frenklach, M. Nucleation of soot: molecular dynamics simulations of pyrene dimerization. Proc. Combust. Inst. 29, 2307–2314 (2002).
Sabbah, H., Biennier, L., Klippenstein, S. J., Sims, I. R. & Rowe, B. R. Exploring the role of PAHs in the formation of soot: pyrene dimerization. J. Phys. Chem. Lett. 1, 2962–2967 (2010).
Chen, P., Colson, S. D., Chupka, W. A. & Berson, J. A. Flash pyrolytic production of rotationally cold free radicals in a supersonic jet: resonant multiphoton spectrum of the 3p2A2”←X2A2” origin band of methyl. J. Phys. Chem. 90, 2319–2321 (1986).
Chen, P., Pallix, J. B., Chupka, W. A. & Colson, S. D. Resonant multiphoton ionization spectrum and electronic structure of CH radical: new states and assignments above 50,000 cm–1. J. Chem. Phys. 86, 516–520 (1987).
Photonionization Cross Section Database Version 2.0 (National Synchrotron Radiation Laboratory, China, 2017); http://flame.nsrl.ustc.edu.cn/database/
Zhang, F., Gu, X. & Kaiser, R. I. Formation of the diphenyl molecule in the crossed beam reaction of phenyl radicals with benzene. J. Chem. Phys. 128, 084315 (2008).
Mebel, A. M., Landera, A. & Kaiser, R. I. Formation mechanisms of naphthalene and indene: from the interstellar medium to combustion flames. J. Phys. Chem. A 121, 901–926 (2017).
Mostefaoui, S., Hoppe, P. & El Goresy, A. In situ discovery of graphite with interstellar isotopic signatures in a chondrule-free clast in an L3 chondrite. Science 280, 1418–1420 (1998).
Smith, P. P. K. & Buseck, P. R. Carbon in the allende meteorite: evidence for poorly graphitized carbon rather than carbyne. Geochim. Cosmochim. Acta. Suppl. 16, 1167–1175 (1982).
Duley, W. W. Chemical evolution of carbonaceous material in interstellar clouds. Astrophys. J. 528, 841–848 (2000).
Amari, S., Lewis, R. S. & Anders, E. Interstellar grains in meteorites: III. Graphite and its noble gases. Geochim. Cosmochim. Acta. 59, 1411–1426 (1995).
Zinner, E., Amari, S., Wopenka, B. & Lewis, R. S. Interstellar graphite in meteorites: isotopic compositions and structural properties of single graphite grains from murchison. Meteoritics 30, 209–226 (1995).
Garvie, L. A. J. & Buseck, P. R. Nanosized carbon-rich grains in carbonaceous chondrite meteorites. Earth Planet. Sci. Lett. 224, 431–439 (2004).
Zega, T. J., Garvie, L. A. J., Dodony, I. & Buseck, P. R. Serpentine nanotubes in the Mighei CM chondrite. Earth Planet. Sci. Lett. 223, 141–146 (2004).
Cami, J., Bernard-Salas, J., Peeters, E. & Malek, S. E. Detection of C60 and C70 in a young planetary nebula. Science 329, 1180–1182 (2010).
Cherchneff, I., Barker, J. R. & Tielens, A. G. G. M. Polycyclic aromatic hydrocarbon formation in carbon-rich stellar envelopes. Astrophys. J. 401, 269–287 (1992).
Cohen, M., Tielens, A. G. G. M. & Bregman, J. D. Mid-infrared spectra of WC 9 Stars: the composition of circumstellar and interstellar dust. Astrophys. J. 344, L13–L16 (1989).
Micelotta, E., Jones, A. & Tielens, A. Polycyclic aromatic hydrocarbon processing in interstellar shocks. Astron. Astrophys. 510, A36 (2010).
Allamandola, L. J., Tielens, A. G. G. M. & Barker, J. R. Interstellar polycyclic aromatic hydrocarbons: the infrared emission bands, the excitation/emission mechanism, and the astrophysical implications. Astrophys. J. Suppl. Ser. 71, 733–775 (1989).
Bernstein, M. P. et al. UV irradiation of polycyclic aromatic hydrocarbons in ices: production of alcohols, quinones, and ethers. Science 283, 1135–1138 (1999).
Cool, T. A. et al. Selective detection of isomers with photoionization mass spectrometry for studies of hydrocarbon flame chemistry. J. Chem. Phys. 119, 8356–8365 (2003).
Qi, F. et al. Isomeric identification of polycyclic aromatic hydrocarbons formed in combustion with tunable vacuum ultraviolet photoionization. Rev. Sci. Instrum. 77, 084101 (2006).
Qi, F. Combustion chemistry probed by synchrotron VUV photoionization mass spectrometry. Proc. Combust. Inst. 34, 33–63 (2013).
Curtiss, L. A., Raghavachari, K., Redfern, P. C., Rassolov, V. & Pople, J. A. Gaussian-3 (G3) theory for molecules containing first and second-row atoms. J. Chem. Phys. 109, 7764–7776 (1998).
Curtiss, L. A., Raghavachari, K., Redfern, P. C., Baboul, A. G. & Pople, J. A. Gaussian-3 theory using coupled cluster energies. Chem. Phys. Lett. 314, 101–107 (1999).
Baboul, A. G., Curtiss, L. A., Redfern, P. C. & Raghavachari, K. Gaussian-3 theory using density functional geometries and zero-point energies. J. Chem. Phys. 110, 7650–7657 (1999).
Frisch, M. J. et al. Gaussian 09 Revision A.1 (Gaussian Inc., Wallingford, CT, 2009).
Georgievskii, Y., Miller, J. A., Burke, M. P. & Klippenstein, S. J. Reformulation and solution of the master equation for multiple-well chemical reactions. J. Phys. Chem. A 117, 12146–12154 (2013).
This work was supported by the US Department of Energy, Basic Energy Sciences DE-FG02-03ER15411 (experimental studies), DE-FG02-04ER15570 (computational studies) and DE-SC0010409 (synthesis of precursor molecules) to the University of Hawaii, to Florida International University, and the University of California Berkeley, respectively. M.A., U.A., B.X. and the experiments at the chemical dynamics beamline at the ALS were supported by the Director, Office of Science, Office of Basic Energy Sciences, of the US Department of Energy under contract no. DE-AC02-05CH11231, through the Gas Phase Chemical Physics Program, Chemical Sciences Division. D.J. acknowledges support through a National Science Foundation Graduate Research Fellowship under grant no. DGE-1106400. The authors also thank X. Tielens (University of Leiden, The Netherlands) for helpful discussions.
The authors declare no competing interests.
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Zhao, L., Kaiser, R.I., Xu, B. et al. Pyrene synthesis in circumstellar envelopes and its role in the formation of 2D nanostructures. Nat Astron 2, 413–419 (2018). https://doi.org/10.1038/s41550-018-0399-y
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