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Kramer MJ, Trump BA, Daemen LL, Balderas-Xicohtencatl R, Cheng Y, Ramirez-Cuesta AJ, Brown CM, Runčevski T. Neutron Vibrational Spectroscopic Study of the Acetylene: Ammonia (1:1) Cocrystal Relevant to Titan, Saturn's Moon. J Phys Chem A 2024; 128:5676-5683. [PMID: 38968334 DOI: 10.1021/acs.jpca.4c02360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/07/2024]
Abstract
The surface of Titan, Saturn's icy moon, is believed to be composed of various molecular minerals with a great diversity in structure and composition. Under the surface conditions, 93 K and 1.45 atm, most small molecules solidify and form minerals, including acetylene and ammonia. These two compounds can not only form single-component solids but also a 1:1 binary cocrystal that exhibits intriguing rotor phase behavior. This cocrystal is a putative mineral on Titan and other planetary bodies such as comets. In addition, the structure of the cocrystal is relevant to fundamental science as it can help better understand the emergence of rotor phases. Here, we present a detailed vibrational neutron spectroscopic study supported by a neutron powder diffraction study on the cocrystal and the single-phase solids. The experimentally observed spectral bands were assigned based on theoretical calculations. The established spectra-properties correlations for the cocrystal corroborate the observed properties. To the best of our knowledge, this study presents the first example of the application of neutron vibrational spectroscopy in studying Titan-relevant organic minerals.
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Affiliation(s)
- Morgan J Kramer
- Department of Chemistry, Southern Methodist University, Dallas, Texas 75275, United States
| | - Benjamin A Trump
- National Institute of Standards and Technology, Center for Neutron Research, Gaithersburg, Maryland 20899, United States
| | - Luke L Daemen
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | | | - Yongqiang Cheng
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | | | - Craig M Brown
- National Institute of Standards and Technology, Center for Neutron Research, Gaithersburg, Maryland 20899, United States
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Tomče Runčevski
- Department of Chemistry, Southern Methodist University, Dallas, Texas 75275, United States
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2
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Karaev E, Gerlach M, Theil K, Garcia GA, Alcaraz C, Loison JC, Fischer I. Photoelectron spectrum of the pyridyl radical. Phys Chem Chem Phys 2024; 26:17042-17047. [PMID: 38836386 DOI: 10.1039/d4cp00688g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
We report the photoelectron spectrum of the pyridyl radical (C5H4N), a species of interest in astrochemistry and combustion. The radicals were produced via hydrogen abstraction in a fluorine discharge and ionized with synchrotron radiation. Mass-selected slow photoelectron spectra of the products were obtained from photoelectron-photoion coincidence spectra. A Franck-Condon simulation based on computed geometries and vibrational frequencies identified contributions of the o- and p-pyridyl radicals. For the o-isomer an adiabatic ionisation energy of 7.70 eV was obtained, in excellent agreement with a computed value of 7.72 eV. The spectrum of o-pyridyl is characterized by a long progression in an in-plane bending mode and the N-C stretch that contains the radical site.
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Affiliation(s)
- Emil Karaev
- University of Würzburg, Institute of Physical and Theoretical Chemistry, Am Hubland, 97074 Würzburg, Germany.
| | - Marius Gerlach
- University of Würzburg, Institute of Physical and Theoretical Chemistry, Am Hubland, 97074 Würzburg, Germany.
| | - Katharina Theil
- University of Würzburg, Institute of Physical and Theoretical Chemistry, Am Hubland, 97074 Würzburg, Germany.
| | - Gustavo A Garcia
- Synchrotron Soleil, L'Orme des Merisiers, St Aubin, B.P. 48, F-91192 Gif sur Yvette, France
| | - Christian Alcaraz
- Universite Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000, 91405 Orsay, France
| | | | - Ingo Fischer
- University of Würzburg, Institute of Physical and Theoretical Chemistry, Am Hubland, 97074 Würzburg, Germany.
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3
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Xiong X, Hu Y. Infrared Spectroscopy of Neutral and Cationic Benzonitrile-Methanol Binary Clusters in Supersonic Jets. Molecules 2024; 29:2744. [PMID: 38930810 PMCID: PMC11206090 DOI: 10.3390/molecules29122744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Revised: 06/01/2024] [Accepted: 06/05/2024] [Indexed: 06/28/2024] Open
Abstract
The formation of nitrogen-containing organic interstellar molecules is of great importance to reveal chemical processes and the origin of life on Earth. Benzonitrile (BN) is one of the simplest nitrogen-containing aromatic molecules in the interstellar medium (ISM) that has been detected in recent years. Methanol (CH3OH) exists widely in interstellar space with high reactivity. Herein, we measured the infrared (IR) spectra of neutral and cationic BN-CH3OH clusters by vacuum ultraviolet (VUV) photoionization combined with time-of-flight mass spectrometry. Combining IR spectra with the density functional theory calculations, we reveal that the BN-CH3OH intends to form a cyclic H-bonded structure in neutral clusters. However, after the ionization of BN-CH3OH clusters, proton-shared N···H···O and N···H···C structures are confirmed to form between BN and CH3OH, with the minor coexistence of H-bond and O-π structures. The formation of the proton-shared structure expands our knowledge of the evolution of the life-related nitrogen-containing molecules in the universe and provides a possible pathway to the further study of biorelevant aromatic organic macromolecules.
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Affiliation(s)
| | - Yongjun Hu
- MOE Key Laboratory of Laser Life Science & Guangdong Provincial Key Laboratory of Laser Life Science, Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, College of Biophotonics, South China Normal University, Guangzhou 510631, China
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4
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Nixon CA. The Composition and Chemistry of Titan's Atmosphere. ACS EARTH & SPACE CHEMISTRY 2024; 8:406-456. [PMID: 38533193 PMCID: PMC10961852 DOI: 10.1021/acsearthspacechem.2c00041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 11/02/2023] [Accepted: 02/02/2024] [Indexed: 03/28/2024]
Abstract
In this review I summarize the current state of knowledge about the composition of Titan's atmosphere and our current understanding of the suggested chemistry that leads to that observed composition. I begin with our present knowledge of the atmospheric composition, garnered from a variety of measurements including Cassini-Huygens, the Atacama Large Millimeter/submillimeter Array, and other ground- and space-based telescopes. This review focuses on the typical vertical profiles of gases at low latitudes rather than global and temporal variations. The main body of the review presents a chemical description of how complex molecules are believed to arise from simpler species, considering all known "stable" molecules-those that have been uniquely identified in the neutral atmosphere. The last section of the review is devoted to the gaps in our present knowledge of Titan's chemical composition and how further work may fill those gaps.
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Affiliation(s)
- Conor A. Nixon
- Planetary Systems Laboratory, NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, Maryland 20771, United
States
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5
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Czaplinski EC, Vu TH, Cable ML, Choukroun M, Malaska MJ, Hodyss R. Experimental Characterization of the Pyridine:Acetylene Co-crystal and Implications for Titan's Surface. ACS EARTH & SPACE CHEMISTRY 2023; 7:597-608. [PMID: 36960425 PMCID: PMC10026175 DOI: 10.1021/acsearthspacechem.2c00377] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/16/2023] [Accepted: 02/16/2023] [Indexed: 06/18/2023]
Abstract
Titan, Saturn's largest moon, has a plethora of organic compounds in the atmosphere and on the surface that interact with each other. Cryominerals such as co-crystals may influence the geologic processes and chemical composition of Titan's surface, which in turn informs our understanding of how Titan may have evolved, how the surface is continuing to change, and the extent of Titan's habitability. Previous works have shown that a pyridine:acetylene (1:1) co-crystal forms under specific temperatures and experimental conditions; however, this has not yet been demonstrated under Titan-relevant conditions. Our work here demonstrates that the pyridine:acetylene co-crystal is stable from 90 K, Titan's average surface temperature, up to 180 K under an atmosphere of N2. In particular, the co-crystal forms via liquid-solid interactions within minutes upon mixing of the constituents at 150 K, as evidenced by distinct, new Raman bands and band shifts. X-ray diffraction (XRD) results indicate moderate anisotropic thermal expansion (about 0.5-1.1%) along the three principal axes between 90-150 K. Additionally, the co-crystal is detectable after being exposed to liquid ethane, implying stability in a residual ethane "wetting" scenario on Titan. These results suggest that the pyridine:acetylene co-crystal could form in specific geologic contexts on Titan that allow for warm environments in which liquid pyridine could persist, and as such, this cryomineral may preserve the evidence of impact, cryovolcanism, or subsurface transport in surface materials.
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6
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Fioroni M, DeYonker NJ. Nitrile regio-synthesis by Ni centers on a siliceous surface: implications in prebiotic chemistry. Chem Commun (Camb) 2022; 58:11579-11582. [PMID: 36168891 DOI: 10.1039/d2cc04361k] [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
By means of quantum chemistry (PBE0/def2-TZVPP; DLPNO-CCSD(T)/cc-pVTZ) and small, but reliable models of Polyhedral Oligomeric Silsesquioxanes (POSS), an array of astrochemically-relevant catalysis products, related to prebiotic and origin of life chemistry, has been theoretically explored. In this work, the heterogeneous phase hydrocyanation reaction of an unsaturated CC bond (propene) catalyzed by a Ni center complexed to a silica surface is analyzed. Of the two possible regioisomers, the branched iso-propyl-cyanide is thermodynamically and kinetically preferred over the linear n-propyl-cyanide (T = 200 K). The formation of nitriles based on a regioselective process has profound implications on prebiotic and origin of life chemistry, as well as deep connections to terrestrial surface chemistry and geochemistry.
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Affiliation(s)
- Marco Fioroni
- Department of Chemistry, 213 Smith Chemistry Building, The University of Memphis, Memphis, TN, USA, 38152.
| | - Nathan J DeYonker
- Department of Chemistry, 213 Smith Chemistry Building, The University of Memphis, Memphis, TN, USA, 38152.
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7
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Vanuzzo G, Marchione D, Mancini L, Liang P, Pannacci G, Recio P, Tan Y, Rosi M, Skouteris D, Casavecchia P, Balucani N. The N( 2D) + CH 2CHCN (Vinyl Cyanide) Reaction: A Combined Crossed Molecular Beam and Theoretical Study and Implications for the Atmosphere of Titan. J Phys Chem A 2022; 126:6110-6123. [PMID: 36053010 PMCID: PMC9483977 DOI: 10.1021/acs.jpca.2c04263] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
The reaction of electronically excited nitrogen atoms,
N(2D), with vinyl cyanide, CH2CHCN, has been
investigated
under single-collision conditions by the crossed molecular beam (CMB)
scattering method with mass spectrometric detection and time-of-flight
(TOF) analysis at the collision energy, Ec, of 31.4 kJ/mol. Synergistic electronic structure calculations of
the doublet potential energy surface (PES) have been performed to
assist in the interpretation of the experimental results and characterize
the overall reaction micromechanism. Statistical (Rice–Ramsperger–Kassel–Marcus,
RRKM) calculations of product branching fractions (BFs) on the theoretical
PES have been carried out at different values of temperature, including
the one corresponding to the temperature (175 K) of Titan’s
stratosphere and at a total energy corresponding to the Ec of the CMB experiment. According to our theoretical
calculations, the reaction is found to proceed via barrierless addition
of N(2D) to the carbon–carbon double bond of CH2=CH–CN, followed by the formation of cyclic
and linear intermediates that can undergo H, CN, and HCN elimination.
In competition, the N(2D) addition to the CN group is also
possible via a submerged barrier, leading ultimately to N2 + C3H3 formation, the most exothermic of all
possible channels. Product angular and TOF distributions have been
recorded for the H-displacement channels leading to the formation
of a variety of possible C3H2N2 isomeric
products. Experimentally, no evidence of CN, HCN, and N2 forming channels was observed. These findings were corroborated
by the theory, which predicts a variety of competing product channels,
following N(2D) addition to the double bond, with the main
ones, at Ec = 31.4 kJ/mol, being six isomeric
H forming channels: c-CH(N)CHCN + H (BF = 35.0%), c-CHNCHCN + H (BF = 28.1%), CH2NCCN + H (BF =
26.3%), c-CH2(N)CCN(cyano-azirine) + H
(BF = 7.4%), trans-HNCCHCN + H (BF = 1.6%), and cis-HNCCHCN + H (BF = 1.3%), while C–C bond breaking
channels leading to c-CH2(N)CH(2H-azirine)
+ CN and c-CH2(N)C + HCN are predicted
to be negligible (0.02% and 0.2%, respectively). The highly exothermic
N2 + CH2CCH (propargyl) channel is also predicted
to be negligible because of the very high isomerization barrier from
the initial addition intermediate to the precursor intermediate able
to lead to products. The predicted product BFs are found to have,
in general, a very weak energy dependence. The above cyclic and linear
products containing an additional C–N bond could be potential
precursors of more complex, N-rich organic molecules that contribute
to the formation of the aerosols on Titan’s upper atmosphere.
Overall, the results are expected to have a significant impact on
the gas-phase chemistry of Titan’s atmosphere and should be
properly included in the photochemical models.
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Affiliation(s)
- Gianmarco Vanuzzo
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Demian Marchione
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Luca Mancini
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Pengxiao Liang
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Giacomo Pannacci
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Pedro Recio
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Yuxin Tan
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Marzio Rosi
- Dipartimento di Ingegneria Civile e Ambientale, Università degli Studi di Perugia, 06125 Perugia, Italy
| | | | - Piergiorgio Casavecchia
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Nadia Balucani
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
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8
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Sources of Nitrogen-, Sulfur-, and Phosphorus-Containing Feedstocks for Prebiotic Chemistry in the Planetary Environment. LIFE (BASEL, SWITZERLAND) 2022; 12:life12081268. [PMID: 36013447 PMCID: PMC9410288 DOI: 10.3390/life12081268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 08/13/2022] [Accepted: 08/17/2022] [Indexed: 11/21/2022]
Abstract
Biochemistry on Earth makes use of the key elements carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur (or CHONPS). Chemically accessible molecules containing these key elements would presumably have been necessary for prebiotic chemistry and the origins of life on Earth. For example, feedstock molecules including fixed nitrogen (e.g., ammonia, nitrite, nitrate), accessible forms of phosphorus (e.g., phosphate, phosphite, etc.), and sources of sulfur (e.g., sulfide, sulfite) may have been necessary for the origins of life, given the biochemistry seen in Earth life today. This review describes potential sources of nitrogen-, sulfur-, and phosphorus-containing molecules in the context of planetary environments. For the early Earth, such considerations may be able to aid in the understanding of our own origins. Additionally, as we learn more about potential environments on other planets (for example, with upcoming next-generation telescope observations or new missions to explore other bodies in our Solar System), evaluating potential sources for elements necessary for life (as we know it) can help constrain the potential habitability of these worlds.
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9
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Wong ML, Bartlett S, Chen S, Tierney L. Searching for Life, Mindful of Lyfe's Possibilities. Life (Basel) 2022; 12:783. [PMID: 35743813 PMCID: PMC9225093 DOI: 10.3390/life12060783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 05/03/2022] [Accepted: 05/18/2022] [Indexed: 11/16/2022] Open
Abstract
We are embarking on a new age of astrobiology, one in which numerous interplanetary missions and telescopes will be designed, built, and launched with the explicit goal of finding evidence for life beyond Earth. Such a profound aim warrants caution and responsibility when interpreting and disseminating results. Scientists must take care not to overstate (or over-imply) confidence in life detection when evidence is lacking, or only incremental advances have been made. Recently, there has been a call for the community to create standards of evidence for the detection and reporting of biosignatures. In this perspective, we wish to highlight a critical but often understated element to the discussion of biosignatures: Life detection studies are deeply entwined with and rely upon our (often preconceived) notions of what life is, the origins of life, and habitability. Where biosignatures are concerned, these three highly related questions are frequently relegated to a low priority, assumed to be already solved or irrelevant to the question of life detection. Therefore, our aim is to bring to the fore how these other major astrobiological frontiers are central to searching for life elsewhere and encourage astrobiologists to embrace the reality that all of these science questions are interrelated and must be furthered together rather than separately. Finally, in an effort to be more inclusive of life as we do not know it, we propose tentative criteria for a more general and expansive characterization of habitability that we call genesity.
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Affiliation(s)
- Michael L. Wong
- Earth & Planets Laboratory, Carnegie Institution for Science, Washington, DC 20015, USA
| | - Stuart Bartlett
- Division of Geological & Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA; (S.B.); (S.C.)
| | - Sihe Chen
- Division of Geological & Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA; (S.B.); (S.C.)
| | - Louisa Tierney
- The Potomac School, Science Engineering & Research Center, McLean, VA 22101, USA;
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10
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Liang P, Mancini L, Marchione D, Vanuzzo G, Ferlin F, Recio P, Tan Y, Pannacci G, Vaccaro L, Rosi M, Casavecchia P, Balucani N. Combined crossed molecular beams and computational study on the N( 2D) + HCCCN(X 1Σ +) reaction and implications for extra-terrestrial environments. Mol Phys 2021. [DOI: 10.1080/00268976.2021.1948126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Pengxiao Liang
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
| | - Luca Mancini
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
| | - Demian Marchione
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
| | - Gianmarco Vanuzzo
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
| | - Francesco Ferlin
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
| | - Pedro Recio
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
| | - Yuxin Tan
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
- ERASMUS+ Visiting Ph.D. student from Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, People’s Republic of China
| | - Giacomo Pannacci
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
| | - Luigi Vaccaro
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
| | - Marzio Rosi
- Dipartimento di Ingegneria Civile e Ambientale, Università degli Studi di Perugia, Perugia, Italy
| | - Piergiorgio Casavecchia
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
| | - Nadia Balucani
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
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Lukianova MA, Volosatova AD, Drabkin VD, Sosulin IS, Kameneva SV, Feldman VI. Radiation-induced transformations of HCN⋯C2H2, HCN⋯C2H4 and HCN⋯C2H6 complexes in noble gas matrices: Synthesis of C3HxN molecules in cryogenic media. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2020.109232] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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12
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Sánchez-Lavega A, García-Muñoz A, Del Río-Gaztelurrutia T, Pérez-Hoyos S, Sanz-Requena JF, Hueso R, Guerlet S, Peralta J. Multilayer hazes over Saturn's hexagon from Cassini ISS limb images. Nat Commun 2020; 11:2281. [PMID: 32385300 PMCID: PMC7210256 DOI: 10.1038/s41467-020-16110-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 04/06/2020] [Indexed: 11/09/2022] Open
Abstract
In June 2015, Cassini high-resolution images of Saturn's limb southwards of the planet's hexagonal wave revealed a system of at least six stacked haze layers above the upper cloud deck. Here, we characterize those haze layers and discuss their nature. Vertical thickness of layers ranged from 7 to 18 km, and they extended in altitude ∼130 km, from pressure level 0.5 bar to 0.01 bar. Above them, a thin but extended aerosol layer reached altitude ∼340 km (0.4 mbar). Radiative transfer modeling of spectral reflectivity shows that haze properties are consistent with particles of diameter 0.07-1.4 μm and number density 100-500 cm-3. The nature of the hazes is compatible with their formation by condensation of hydrocarbon ices, including acetylene and benzene at higher altitudes. Their vertical distribution could be due to upward propagating gravity waves generated by dynamical forcing by the hexagon and its associated eastward jet.
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Affiliation(s)
- A Sánchez-Lavega
- Departamento Física Aplicada I, Escuela de Ingeniería de Bilbao, Universidad del País Vasco UPV/EHU, Bilbao, Spain.
| | - A García-Muñoz
- Zentrum für Astronomie und Astrophysik, Technische Universität Berlin, Berlin, Germany
| | - T Del Río-Gaztelurrutia
- Departamento Física Aplicada I, Escuela de Ingeniería de Bilbao, Universidad del País Vasco UPV/EHU, Bilbao, Spain
| | - S Pérez-Hoyos
- Departamento Física Aplicada I, Escuela de Ingeniería de Bilbao, Universidad del País Vasco UPV/EHU, Bilbao, Spain
| | - J F Sanz-Requena
- Departamento de Física Teórica, Atómica y Optica, Universidad de Valladolid, Valladolid, Spain
| | - R Hueso
- Departamento Física Aplicada I, Escuela de Ingeniería de Bilbao, Universidad del País Vasco UPV/EHU, Bilbao, Spain
| | - S Guerlet
- Laboratoire de Meteorologie Dynamique/Institut Pierre-Simon Laplace (LMD/IPSL), Sorbonne Universite, Centre National de la Recherche Scientifique (CNRS), Ecole Polytechnique, Ecole Normale Superieure (ENS), Paris, France
| | - J Peralta
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Kanagawa, Japan
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13
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Li Y, Song W, Jiang N, Zhang Z, Xie M, Hu Y. Structural rearrangement of the acrylonitrile (AN) cluster in the gas phase under VUV one-photon radiation explored by mass-selected infrared spectroscopy. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 226:117620. [PMID: 31610467 DOI: 10.1016/j.saa.2019.117620] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 07/27/2019] [Accepted: 10/06/2019] [Indexed: 06/10/2023]
Abstract
Acrylonitrile (AN), one of the most abundant nitriles in space, is considered to closely relate to the formation of interstellar prebiotic nitrogen-containing aromatics. Herein, we measured the vibrational spectra of acrylonitrile cluster cations (AN)2,3+ in a supersonic jet using infrared (IR) dissociation with vacuum-ultraviolet (VUV) photoionization and time-of-flight mass spectroscopy. Interestingly, the observed IR spectra demonstrate that a new molecular ion [Formula: see text] , is generated from the dimer and trimer of AN upon VUV single-photo ionization. Calculation results reveal that the new molecular cations can be generated through a relative low energy barrier after ionization of the neutral (AN)2. However, the reaction pathways are barrierless for the trimer, in which the third solvent AN acts as a catalyst. The mechanisms of those reactions also have been discussed in detail. This study contributes to a deeper understanding of ion-molecule reaction in gas-phase and the quest for the formation of prebiotic N -containing molecules in the outer space.
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Affiliation(s)
- Yujian Li
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, South China Normal University, Guangzhou, 510631, PR China
| | - Wentao Song
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, South China Normal University, Guangzhou, 510631, PR China
| | - Ningjing Jiang
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, South China Normal University, Guangzhou, 510631, PR China
| | - Zhaoli Zhang
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, South China Normal University, Guangzhou, 510631, PR China
| | - Min Xie
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, South China Normal University, Guangzhou, 510631, PR China.
| | - Yongjun Hu
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, South China Normal University, Guangzhou, 510631, PR China.
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14
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Reusch E, Holzmeier F, Gerlach M, Fischer I, Hemberger P. Decomposition of Picolyl Radicals at High Temperature: A Mass Selective Threshold Photoelectron Spectroscopy Study. Chemistry 2019; 25:16652-16659. [PMID: 31637775 PMCID: PMC6972682 DOI: 10.1002/chem.201903937] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 10/16/2019] [Indexed: 01/24/2023]
Abstract
The reaction products of the picolyl radicals at high temperature were characterized by mass-selective threshold photoelectron spectroscopy in the gas phase. Aminomethylpyridines were pyrolyzed to initially produce picolyl radicals (m/z=92). At higher temperatures further thermal reaction products are generated in the pyrolysis reactor. All compounds were identified by mass-selected threshold photoelectron spectroscopy and several hitherto unexplored reactive molecules were characterized. The mechanism for several dissociation pathways was outlined in computations. The spectrum of m/z=91, resulting from hydrogen loss of picolyl, shows four isomers, two ethynyl pyrroles with adiabatic ionization energies (IEad ) of 7.99 eV (2-ethynyl-1H-pyrrole) and 8.12 eV (3-ethynyl-1H-pyrrole), and two cyclopentadiene carbonitriles with IE's of 9.14 eV (cyclopenta-1,3-diene-1-carbonitrile) and 9.25 eV (cyclopenta-1,4-diene-1-carbonitrile). A second consecutive hydrogen loss forms the cyanocyclopentadienyl radical with IE's of 9.07 eV (T0 ) and 9.21 eV (S1 ). This compound dissociates further to acetylene and the cyanopropynyl radical (IE=9.35 eV). Furthermore, the cyclopentadienyl radical, penta-1,3-diyne, cyclopentadiene and propargyl were identified in the spectra. Computations indicate that dissociation of picolyl proceeds initially via a resonance-stabilized seven-membered ring.
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Affiliation(s)
- Engelbert Reusch
- Institute of Physical and Theoretical ChemistryUniversity of WürzburgAm Hubland Süd97074WürzburgGermany
| | - Fabian Holzmeier
- Dipartimento di FisicaPolitecnico di MilanoPiazza Leonardo da Vinci 3220133MilanoItaly
| | - Marius Gerlach
- Institute of Physical and Theoretical ChemistryUniversity of WürzburgAm Hubland Süd97074WürzburgGermany
| | - Ingo Fischer
- Institute of Physical and Theoretical ChemistryUniversity of WürzburgAm Hubland Süd97074WürzburgGermany
| | - Patrick Hemberger
- Laboratory for Femtochemistry and Synchrotron RadiationPaul Scherrer Institut (PSI)5232VilligenSwitzerland
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15
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Buildup of Abiotic Oxygen and Ozone in Moist Atmospheres of Temperate Terrestrial Exoplanets and Its Impact on the Spectral Fingerprint in Transit Observations. ACTA ACUST UNITED AC 2018. [DOI: 10.3847/1538-4357/aaca36] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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16
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Neish CD, Lorenz RD, Turtle EP, Barnes JW, Trainer MG, Stiles B, Kirk R, Hibbitts CA, Malaska MJ. Strategies for Detecting Biological Molecules on Titan. ASTROBIOLOGY 2018; 18:571-585. [PMID: 29718687 DOI: 10.1089/ast.2017.1758] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Saturn's moon Titan has all the ingredients needed to produce "life as we know it." When exposed to liquid water, organic molecules analogous to those found on Titan produce a range of biomolecules such as amino acids. Titan thus provides a natural laboratory for studying the products of prebiotic chemistry. In this work, we examine the ideal locales to search for evidence of, or progression toward, life on Titan. We determine that the best sites to identify biological molecules are deposits of impact melt on the floors of large, fresh impact craters, specifically Sinlap, Selk, and Menrva craters. We find that it is not possible to identify biomolecules on Titan through remote sensing, but rather through in situ measurements capable of identifying a wide range of biological molecules. Given the nonuniformity of impact melt exposures on the floor of a weathered impact crater, the ideal lander would be capable of precision targeting. This would allow it to identify the locations of fresh impact melt deposits, and/or sites where the melt deposits have been exposed through erosion or mass wasting. Determining the extent of prebiotic chemistry within these melt deposits would help us to understand how life could originate on a world very different from Earth. Key Words: Titan-Prebiotic chemistry-Solar system exploration-Impact processes-Volcanism. Astrobiology 18, 571-585.
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Affiliation(s)
- Catherine D Neish
- 1 Department of Earth Sciences, The University of Western Ontario , London, Canada
| | - Ralph D Lorenz
- 2 The Johns Hopkins Applied Physics Laboratory , Laurel, Maryland
| | | | - Jason W Barnes
- 3 Department of Physics, University of Idaho , Moscow, Idaho
| | | | - Bryan Stiles
- 5 Jet Propulsion Laboratory, California Institute of Technology , Pasadena, California
| | - Randolph Kirk
- 6 United States Geological Survey, Astrogeology Science Center , Flagstaff, Arizona
| | | | - Michael J Malaska
- 5 Jet Propulsion Laboratory, California Institute of Technology , Pasadena, California
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17
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Mandt K, Luspay-Kuti A, Hamel M, Jessup KL, Hue V, Kammer J, Filwett R. Photochemistry on Pluto: part II HCN and nitrogen isotope fractionation. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 2017; 472:118-128. [PMID: 31105342 PMCID: PMC6525008 DOI: 10.1093/mnras/stx1587] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We have converted our Titan one-dimensional photochemical model to simulate the photo- chemistry of Pluto's atmosphere and include condensation and aerosol trapping in the model. We find that condensation and aerosol trapping are important processes in producing the HCN altitude profile observed by the Atacama Large Millimeter Array (ALMA). The nitrogen iso- tope chemistry in Pluto's atmosphere does not appear to significantly fractionate the isotope ratio between N2 and HCN as occurs at Titan. However, our simulations only cover a brief period of time in a Pluto year, and thus only a brief portion of the solar forcing conditions that Pluto's atmosphere experiences. More work is needed to evaluate photochemical fractionation over a Pluto year. Condensation and aerosol trapping appear to have a major impact on the altitude profile of the isotope ratio in HCN. Since ALMA did not detect HC15N in Pluto's atmosphere, we conclude that condensation and aerosol trapping must be much more efficient for HC15N compared to HC14N. The large uncertainty in photochemical fractionation makes it difficult to use any potential current measurement of 14N/15N in N2 to determine the origin of Pluto's nitrogen. More work is needed to understand photochemical fractionation and to evaluate how condensation, sublimation and aerosol trapping will fractionate N2 and HCN.
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Affiliation(s)
- Kathleen Mandt
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78238, USA
- Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Blvd., San Antonio, TX 78249, USA
- Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd., Laurel, MD 20723, USA
| | - Adrienn Luspay-Kuti
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78238, USA
| | - Mark Hamel
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78238, USA
- Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Blvd., San Antonio, TX 78249, USA
| | - Kandis-Lea Jessup
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78238, USA
| | - Vincent Hue
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78238, USA
| | - Josh Kammer
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78238, USA
| | - Rachael Filwett
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78238, USA
- Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Blvd., San Antonio, TX 78249, USA
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18
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Palmer MY, Cordiner MA, Nixon CA, Charnley SB, Teanby NA, Kisiel Z, Irwin PGJ, Mumma MJ. ALMA detection and astrobiological potential of vinyl cyanide on Titan. SCIENCE ADVANCES 2017; 3:e1700022. [PMID: 28782019 PMCID: PMC5533535 DOI: 10.1126/sciadv.1700022] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 06/27/2017] [Indexed: 06/07/2023]
Abstract
Recent simulations have indicated that vinyl cyanide is the best candidate molecule for the formation of cell membranes/vesicle structures in Titan's hydrocarbon-rich lakes and seas. Although the existence of vinyl cyanide (C2H3CN) on Titan was previously inferred using Cassini mass spectrometry, a definitive detection has been lacking until now. We report the first spectroscopic detection of vinyl cyanide in Titan's atmosphere, obtained using archival data from the Atacama Large Millimeter/submillimeter Array (ALMA), collected from February to May 2014. We detect the three strongest rotational lines of C2H3CN in the frequency range of 230 to 232 GHz, each with >4σ confidence. Radiative transfer modeling suggests that most of the C2H3CN emission originates at altitudes of ≳200 km, in agreement with recent photochemical models. The vertical column densities implied by our best-fitting models lie in the range of 3.7 × 1013 to 1.4 × 1014 cm-2. The corresponding production rate of vinyl cyanide and its saturation mole fraction imply the availability of sufficient dissolved material to form ~107 cell membranes/cm3 in Titan's sea Ligeia Mare.
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Affiliation(s)
- Maureen Y. Palmer
- NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771, USA
- Department of Chemistry, St. Olaf College, 1520 St. Olaf Avenue, Northfield, MN 55057, USA
- Department of Physics, Catholic University of America, Washington, DC 20064, USA
| | - Martin A. Cordiner
- NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771, USA
- Department of Physics, Catholic University of America, Washington, DC 20064, USA
| | - Conor A. Nixon
- NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771, USA
| | - Steven B. Charnley
- NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771, USA
| | - Nicholas A. Teanby
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS8 1RJ, UK
| | - Zbigniew Kisiel
- Institute of Physics, Polish Academy of Sciences, Al. Lotnikøw 32/46, 02-668 Warszawa, Poland
| | - Patrick G. J. Irwin
- Atmospheric, Oceanic and Planetary Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, UK
| | - Michael J. Mumma
- NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771, USA
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19
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Reusch E, Holzmeier F, Constantinidis P, Hemberger P, Fischer I. Isomer-Selective Generation and Spectroscopic Characterization of Picolyl Radicals. Angew Chem Int Ed Engl 2017; 56:8000-8003. [DOI: 10.1002/anie.201703433] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Indexed: 11/10/2022]
Affiliation(s)
- Engelbert Reusch
- Institut für Physikalische und Theoretische Chemie; Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Fabian Holzmeier
- Institut für Physikalische und Theoretische Chemie; Universität Würzburg; Am Hubland 97074 Würzburg Germany
- Present address: Institut des Sciences Moléculaires d'Orsay ISMO (UMR 8214 CNRS), Bâtiment 350; Université Paris-Saclay; 91405 Orsay Cedex France
| | - Philipp Constantinidis
- Institut für Physikalische und Theoretische Chemie; Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Patrick Hemberger
- Laboratory for Femtochemistry and Synchrotron Radiation; Paul Scherrer Institut (PSI); 5232 Villigen Switzerland
| | - Ingo Fischer
- Institut für Physikalische und Theoretische Chemie; Universität Würzburg; Am Hubland 97074 Würzburg Germany
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20
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Reusch E, Holzmeier F, Constantinidis P, Hemberger P, Fischer I. Isomerenselektive Erzeugung und spektroskopische Charakterisierung der Picolyl-Radikale. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201703433] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Engelbert Reusch
- Institut für Physikalische und Theoretische Chemie; Universität Würzburg; Am Hubland 97074 Würzburg Deutschland
| | - Fabian Holzmeier
- Institut für Physikalische und Theoretische Chemie; Universität Würzburg; Am Hubland 97074 Würzburg Deutschland
- Institut des Sciences Moléculaires d'Orsay ISMO (UMR 8214 CNRS), Bâtiment 350; Université Paris-Saclay; 91405 Orsay Cedex Frankreich
| | - Philipp Constantinidis
- Institut für Physikalische und Theoretische Chemie; Universität Würzburg; Am Hubland 97074 Würzburg Deutschland
| | - Patrick Hemberger
- Laboratory for Femtochemistry and Synchrotron Radiation; Paul Scherrer Institut (PSI); 5232 Villigen Schweiz
| | - Ingo Fischer
- Institut für Physikalische und Theoretische Chemie; Universität Würzburg; Am Hubland 97074 Würzburg Deutschland
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21
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Ennis C, Auchettl R, Ruzi M, Robertson EG. Infrared characterisation of acetonitrile and propionitrile aerosols under Titan's atmospheric conditions. Phys Chem Chem Phys 2017; 19:2915-2925. [DOI: 10.1039/c6cp08110j] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Acetonitrile and propionitrile aerosols were generated under simulated Titan conditions where new insight into the ice morphology, particle size and formation/diffusion kinetics has been extracted by online infrared spectroscopy.
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Affiliation(s)
- C. Ennis
- Department of Chemistry and Physics
- La Trobe Institute for Molecular Science
- La Trobe University
- Victoria
- Australia
| | - R. Auchettl
- Department of Chemistry and Physics
- La Trobe Institute for Molecular Science
- La Trobe University
- Victoria
- Australia
| | - M. Ruzi
- Department of Chemistry and Physics
- La Trobe Institute for Molecular Science
- La Trobe University
- Victoria
- Australia
| | - E. G. Robertson
- Department of Chemistry and Physics
- La Trobe Institute for Molecular Science
- La Trobe University
- Victoria
- Australia
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