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He C, Luo Y, Doddipatla S, Yang Z, Millar TJ, Sun R, Kaiser RI. Gas-phase formation of silicon monoxide via non-adiabatic reaction dynamics and its role as a building block of interstellar silicates. Phys Chem Chem Phys 2022; 24:19761-19772. [PMID: 35971984 DOI: 10.1039/d2cp02188a] [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
Silicon monoxide (SiO) is classified as a key precursor and fundamental molecular building block to interstellar silicate nanoparticles, which play an essential role in the synthesis of molecular building blocks connected to the Origins of Life. In the cold interstellar medium, silicon monoxide is of critical importance in initiating a series of elementary chemical reactions leading to larger silicon oxides and eventually to silicates. To date, the fundamental formation mechanisms and chemical dynamics leading to gas phase silicon monoxide have remained largely elusive. Here, through a concerted effort between crossed molecular beam experiments and electronic structure calculations, it is revealed that instead of forming highly-stable silicon dioxide (SiO2), silicon monoxide can be formed via a barrierless, exoergic, single-collision event between ground state molecular oxygen and atomic silicon involving non-adiabatic reaction dynamics through various intersystem crossings. Our research affords persuasive evidence for a likely source of highly rovibrationally excited silicon monoxide in cold molecular clouds thus initiating the complex chain of exoergic reactions leading ultimately to a population of silicates at low temperatures in our Galaxy.
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Affiliation(s)
- Chao He
- Department of Chemistry, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA.
| | - Yuheng Luo
- Department of Chemistry, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA.
| | - Srinivas Doddipatla
- Department of Chemistry, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA.
| | - Zhenghai Yang
- Department of Chemistry, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA.
| | - Tom J Millar
- School of Mathematics and Physics, Queen's University Belfast, University Road, Belfast, BT7 1NN, UK
| | - Rui Sun
- Department of Chemistry, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA.
| | - Ralf I Kaiser
- Department of Chemistry, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA.
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Zamirri L, Pantaleone S, Ugliengo P. Carbon monoxide adsorption at forsterite surfaces as models of interstellar dust grains: An unexpected bathochromic (red) shift of the CO stretching frequency. J Chem Phys 2019; 150:064702. [PMID: 30770002 DOI: 10.1063/1.5075632] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Carbon monoxide (CO) is one of the most abundant species in the interstellar medium (ISM). In the colder regions of the ISM, it can directly adsorb onto exposed Mg cations of forsterite (Fo, Mg2SiO4), one of the main constituents of the dust grains. Its energetic of adsorption can strongly influence the chemico-physical evolution of cold interstellar clouds; thus, a detailed description of this process is desirable. We recently simulated the CO adsorption on crystalline Fo surfaces by computer ab initio methods and, surprisingly, reported cases where the CO stretching frequency underwent a bathochromic (red) shift (i.e., it is lowered with respect to the CO gas phase frequency), usually not experimentally observed for CO adsorbed onto oxides with non-d cations, like the present case. Here, we elucidate in deep when and under which conditions this case may happen and concluded that this red shift may be related to peculiar surface sites occurring at the morphologically complex Fo surfaces. The reasons for the red shift are linked to both the quadrupolar nature of the CO molecule and the role of dispersion interactions with surfaces of complex morphology. The present work, albeit speculative, suggests that, at variance with CO adsorption on simple oxides like MgO, the CO spectrum may exhibit features at lower frequencies than the reference gas frequency when CO is adsorbed on complex oxides, even in the absence of transition metal ions.
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Affiliation(s)
- Lorenzo Zamirri
- Dipartimento di Chimica, Università degli Studi di Torino, Via P. Giuria 7, I-10125 Torino, Italy
| | - Stefano Pantaleone
- Departament de Química, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain
| | - Piero Ugliengo
- Dipartimento di Chimica, Università degli Studi di Torino, Via P. Giuria 7, I-10125 Torino, Italy
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Abstract
We have discovered nine presolar silicate grains from the carbonaceous chondrite Acfer 094. Their anomalous oxygen isotopic compositions indicate formation in the atmospheres of evolved stars. Two grains are identified as pyroxene, two as olivine, one as a glass with embedded metal and sulfides (GEMS), and one as an Al-rich silicate. One grain is enriched in 26Mg, which is attributed to the radioactive decay of 26Al and provides information about mixing processes in the parent star. This discovery opens new means for studying stellar processes and conditions in various solar system environments.
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Affiliation(s)
- Ann N Nguyen
- Laboratory for Space Sciences and the Physics Department, Washington University, St. Louis, MO 63130, USA.
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Kohara S, Suzuya K, Takeuchi K, Loong CK, Grimsditch M, Weber JKR, Tangeman JA, Key TS. Glass Formation at the Limit of Insufficient Network Formers. Science 2004; 303:1649-52. [PMID: 15016995 DOI: 10.1126/science.1095047] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Inorganic glasses normally exhibit a network of interconnected, covalent-bonded, structural elements that has no long-range order. In silicate glasses, the network formers are based on SiO4 tetrahedra interconnected through oxygen atoms at the corners. Conventional wisdom implies that alkaline and alkaline-earth orthosilicate materials cannot be vitrified, because they do not contain sufficient network-forming SiO2 to establish the needed interconnectivity. We studied a bulk magnesium orthosilicate glass obtained by containerless melting and cooling. We found that the role of network former was largely taken on by corner and edge sharing of highly distorted, ionic Mg-O species that adopt 4-, 5-, and 6-coordination with oxygen. The results suggest that similar glassy phases may be found in the containerless environment of interstellar space.
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Affiliation(s)
- S Kohara
- Japan Synchrotron Radiation Research Institute, Mikazuki, Sayo, Hyogo 679-5198, Japan
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Kemper F, Jäger C, Waters LBFM, Henning T, Molster FJ, Barlow MJ, Lim T, de Koter A. Detection of carbonates in dust shells around evolved stars. Nature 2002; 415:295-7. [PMID: 11797000 DOI: 10.1038/415295a] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Carbonates on large Solar System bodies like Earth and Mars (the latter represented by the meteorite ALH84001) form through the weathering of silicates in a watery (CO3)2- solution. The presence of carbonates in interplanetary dust particles and asteroids (again, represented by meteorites) is not completely understood, but has been attributed to aqueous alteration on a large parent body, which was subsequently shattered into smaller pieces. Despite efforts, the presence of carbonates outside the Solar System has hitherto not been established. Here we report the discovery of the carbonates calcite and dolomite in the dust shells of evolved stars, where the conditions are too primitive for the formation of large parent bodies with liquid water. These carbonates, therefore, are not formed by aqueous alteration, but perhaps through processes on the surfaces of dust or ice grains or gas phase condensation. The presence of carbonates which did not form by aqueous alteration suggests that some of the carbonates found in Solar System bodies no longer provide direct evidence that liquid water was present on large parent bodies early in the history of the Solar System.
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Affiliation(s)
- F Kemper
- Astronomical Institute "Anton Pannekoek", University of Amsterdam, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands.
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Muñoz O, Volten H, de Haan JF, Vassen W, Hovenier JW. Experimental determination of scattering matrices of randomly oriented fly ash and clay particles at 442 and 633 nm. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000jd000164] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Volten H, Muñoz O, Rol E, de Haan JF, Vassen W, Hovenier JW, Muinonen K, Nousiainen T. Scattering matrices of mineral aerosol particles at 441.6 nm and 632.8 nm. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2001jd900068] [Citation(s) in RCA: 335] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Mennella V, Brucato JR, Colangeli L. Carbon and silicate grains in the laboratory as analogues of cosmic dust. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2001; 57:787-795. [PMID: 11345254 DOI: 10.1016/s1386-1425(00)00444-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Carbon and silicate grains are the two main components of cosmic dust. There is increasing spectroscopic evidence that their composition varies according to the cosmic environment and the experienced processing. Irradiation from ultraviolet photons and cosmic rays, as well as chemical interactions with the interstellar gas play a crucial role for grain transformation. The study of 'laboratory analogues' represents a powerful tool to better understand the nature and evolution of cosmic materials. In particular, simulations of grain processing are fundamental to outline an evolutionary pathway for interstellar particles. In the present work, we discuss the ultraviolet and infrared spectral changes induced by thermal annealing, ultraviolet irradiation, ion irradiation and hydrogen atom bombardment in carbon and silicate analogue materials. The laboratory results give the opportunity to shed light on the long-standing problems of the attribution of ultraviolet and infrared interstellar spectral features.
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Affiliation(s)
- V Mennella
- Osservatorio Astronomico di Capodimonte, Naples, Italy.
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Hill HG, Grady CA, Nuth JA, Hallenbeck SL, Sitko ML. Constraints on nebular dynamics and chemistry based on observations of annealed magnesium silicate grains in comets and in disks surrounding Herbig Ae/Be stars. Proc Natl Acad Sci U S A 2001; 98:2182-7. [PMID: 11226213 PMCID: PMC33388 DOI: 10.1073/pnas.051530998] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Understanding dynamic conditions in the Solar Nebula is the key to prediction of the material to be found in comets. We suggest that a dynamic, large-scale circulation pattern brings processed dust and gas from the inner nebula back out into the region of cometesimal formation-extending possibly hundreds of astronomical units (AU) from the sun-and that the composition of comets is determined by a chemical reaction network closely coupled to the dynamic transport of dust and gas in the system. This scenario is supported by laboratory studies of Mg silicates and the astronomical data for comets and for protoplanetary disks associated with young stars, which demonstrate that annealing of nebular silicates must occur in conjunction with a large-scale circulation. Mass recycling of dust should have a significant effect on the chemical kinetics of the outer nebula by introducing reduced, gas-phase species produced in the higher temperature and pressure environment of the inner nebula, along with freshly processed grains with "clean" catalytic surfaces to the region of cometesimal formation. Because comets probably form throughout the lifetime of the Solar Nebula and processed (crystalline) grains are not immediately available for incorporation into the first generation of comets, an increasing fraction of dust incorporated into a growing comet should be crystalline olivine and this fraction can serve as a crude chronometer of the relative ages of comets. The formation and evolution of key organic and biogenic molecules in comets are potentially of great consequence to astrobiology.
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Affiliation(s)
- H G Hill
- Code 691, National Aeronautics and Space Administration, Goddard Space Flight Center, Greenbelt, MD 20771, USA.
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