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Статті в журналах з теми "Complex organic molecules"

Автор: Grafiati

Опубліковано: 10 березня 2023

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1

Herbst, Eric, and Ewine F. van Dishoeck. "Complex Organic Interstellar Molecules." Annual Review of Astronomy and Astrophysics 47, no. 1 (September 2009): 427–80. http://dx.doi.org/10.1146/annurev-astro-082708-101654.

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2

Öberg, Karin I., Edith C. Fayolle, John B. Reiter, and Claudia Cyganowski. "Complex molecule formation around massive young stellar objects." Faraday Discuss. 168 (2014): 81–101. http://dx.doi.org/10.1039/c3fd00146f.

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Interstellar complex organic molecules were first identified in the hot inner regions of massive young stellar objects (MYSOs), but have more recently been found in many colder sources, indicating that complex molecules can form at a range of temperatures. However, individually these observations provide limited constraints on how complex molecules form, and whether the same formation pathways dominate in cold, warm and hot environments. To address these questions, we use spatially resolved observations from the Submillimeter Array of three MYSOs together with mostly unresolved literature data to explore how molecular ratios depend on environmental parameters, especially temperature. Towards the three MYSOs, we find multiple complex organic emission peaks characterized by different molecular compositions and temperatures. In particular, CH₃CCH and CH₃CN seem to always trace a lukewarm (T ≈ 60 K) and a hot (T > 100 K) complex chemistry, respectively. These spatial trends are consistent with abundance–temperature correlations of four representative complex organics – CH₃CCH, CH₃CN, CH₃OCH₃ and CH₃CHO – in a large sample of complex molecule hosts mined from the literature. Together, these results indicate a general chemical evolution with temperature, i.e. that new complex molecule formation pathways are activated as a MYSO heats up. This is qualitatively consistent with model predictions. Furthermore, these results suggest that ratios of complex molecules may be developed into a powerful probe of the evolutionary stage of a MYSO, and may provide information about its formation history.

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3

Soma, Tatsuya, Nami Sakai, Yoshimasa Watanabe, and Satoshi Yamamoto. "Complex Organic Molecules in Taurus Molecular Cloud-1." Astrophysical Journal 854, no. 2 (February 16, 2018): 116. http://dx.doi.org/10.3847/1538-4357/aaa70c.

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4

Dartois, E., M. Chabot, T. Id Barkach, H. Rothard, B. Augé, A. N. Agnihotri, A. Domaracka, and P. Boduch. "Non-thermal desorption of complex organic molecules." Astronomy & Astrophysics 627 (July 2019): A55. http://dx.doi.org/10.1051/0004-6361/201834787.

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Context. The occurrence of complex organic molecules (COMs) in the gas phase at low temperature in the dense phases of the interstellar medium suggests that a non-thermal desorption mechanism is at work because otherwise, COMs should condense within a short timescale onto dust grains. Vacuum ultraviolet (VUV) photodesorption has been shown to be much less efficient for complex organic molecules, such as methanol, because mostly photoproducts are ejected. The induced photolysis competes with photodesorption for large COMs, which considerably lowers the efficiency to desorb intact molecules. Aims. We pursue an experimental work that has already shown that water molecules, the dominant ice mantle species, can be efficiently sputtered by cosmic rays. We investigate the sputtering efficiency of complex organic molecules that are observed either in the ice mantles of interstellar dense clouds directly by infrared spectroscopy (CH3OH), or that are observed in the gas phase by millimeter telescopes (CH3COOCH3) and that could be released from interstellar grain surfaces. Methods. We irradiated ice films containing complex organic molecules (methanol and methyl acetate) and water with swift heavy ions in the electronic sputtering regime. We monitored the infrared spectra of the film as well as the species released to the gas phase with a mass spectrometer. Results. We demonstrate that when methanol or methyl acetate is embedded in a water-ice mantle exposed to cosmic rays, a large portion is sputtered as an intact molecule, with a sputtering yield close to that of the main water-ice matrix. This must be even more true for the case of more volatile ice matrices, such as those that are embedded in carbon monoxide. Conclusions. Cosmic rays penetrating deep into dense clouds provide an efficient mechanism to desorb complex organic molecules. Compared to the VUV photons, which are induced by the interaction of cosmic rays, a large portion desorb as intact molecules with a proportion corresponding to the time-dependent bulk composition of the ice mantle, the latter evolving with time as a function of fluence due to the radiolysis of the bulk.

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5

Walsh, Catherine, Tom J. Millar, Hideko Nomura, Eric Herbst, Susanna Widicus Weaver, Yuri Aikawa, Jacob C. Laas, and Anton I. Vasyunin. "Complex organic molecules in protoplanetary disks." Astronomy & Astrophysics 563 (February 28, 2014): A33. http://dx.doi.org/10.1051/0004-6361/201322446.

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6

Faure, Alexandre, Eric Josselin, Laurent Wiesenfeld, and Cecilia Ceccarelli. "Collisional excitation of complex organic molecules." Proceedings of the International Astronomical Union 4, S251 (February 2008): 137–38. http://dx.doi.org/10.1017/s1743921308021376.

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AbstractA major difficulty in modelling the infrared and (sub)millimeter spectra of gas-phase complex organic molecules is the lack of state-to-state collisional rate coefficients. Accurate quantum or classical scattering calculations for large polyatomic species are indeed computationally highly challenging, particularly when both rotation and low frequency vibrations such as bending and torsional modes are involved. We briefly present here an approximate approach to estimate and/or extrapolate rotational and rovibrational rates for polyatomic molecules with many degrees of freedom.

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7

Liu, Sheng-Yuan. "Interferometric Observations of Complex Organic Molecules." Proceedings of the International Astronomical Union 1, S231 (March 21, 2006): 217. http://dx.doi.org/10.1017/s1743921306007216.

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8

Cruikshank, D. P. "Complex Organic Solid Matter in the Outer Solar System." Highlights of Astronomy 13 (2005): 902–3. http://dx.doi.org/10.1017/s1539299600017482.

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Complex organic molecular material of non-biological origin is found in abundance in the interstellar dust in our Galaxy, and is also detected in other galaxies. Some of this material was incorporated into the solar nebula and is now found in some Solar System bodies. While some pre-solar organic material has been preserved, synthesis of complex organics in planetary atmospheres and on icy surfaces has been in progress for the entire age of the Solar System. Refractory organic solids have proven difficult to detect by traditional spectroscopic techniques, and their presence is usually inferred from the low albedo and (often) red color of the surfaces of small bodies in the outer Solar System (OSS). Color in complex organic molecules, such as polymers and polycyclic aromatic hydrocarbons, is caused by absorption in the UV and visible spectral regions arising from electronic transitions connected primarily with C-C and C-0 bonding. In particular, large hydrocarbon molecules with conjugated (alternating pairs of double and single) C-C bonds have color because the electronic transitions of the de-localized pi electrons extend into the visible spectral region; the longer the conjugated chain, the further is the extension to longer wavelength, with the result that especially large molecular material appears black.

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9

Choudhury, R., P. Schilke, G. Stéphan, E. Bergin, T. Möller, A. Schmiedeke, and A. Zernickel. "Evolution of complex organic molecules in hot molecular cores." Astronomy & Astrophysics 575 (February 25, 2015): A68. http://dx.doi.org/10.1051/0004-6361/201424499.

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10

Ceccarelli, Cecilia. "Organic molecules in protostellar environments." Proceedings of the International Astronomical Union 4, S251 (February 2008): 79–88. http://dx.doi.org/10.1017/s174392130802125x.

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AbstractThe sequence that brings matter from a molecular cloud to a fully developed star plus planetary system seems to be a unique and rich chemistry laboratory where, step by step, molecular complexity increases. During the cold pre-collapse phase, atoms and simple molecules, like CO, freeze out onto the dust grains, forming icy mantles. Reactions on the grain surfaces likely form hydrogenated molecules (notably H2O, CH4, H2CO, CH3OH, and NH3) and perhaps even more complex organic molecules. The hallmark of this era is the super-deuteration phenomenon, i. e. the abnormal enhancement of molecules containing one or more D atoms instead of H atoms, by up to 13 orders of magnitude with respect to the cosmic elemental D/H ratio (~10−5). The frozen molecules are released into the gas upon warming by the forming star and undergo reactions which further increase the molecular complexity, leading to several complex organic molecules. Products of this efficient chemical factory are observed in the hot corinos, which are warm (~100 K), dense (~107–108 cm−3) solar-system-sized regions at the centre of the collapsing envelopes of solar type protostars. In this contribution, I review what is known about the organic molecules in protostellar environments, with emphasis on the hot corinos, and how possibly the organic molecules formed at this stage may constitute an heritage for the forming planetary system.

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11

Dartois, E., M. Chabot, A. Bacmann, P. Boduch, A. Domaracka, and H. Rothard. "Non-thermal desorption of complex organic molecules." Astronomy & Astrophysics 634 (February 2020): A103. http://dx.doi.org/10.1051/0004-6361/201936934.

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Aims. Methanol ice is embedded in interstellar ice mantles present in dense molecular clouds. We aim to measure the sputtering efficiencies starting from different ice mantles of varying compositions experimentally, in order to evaluate their potential impact on astrochemical models. The sputtering yields of complex organic molecules is of particular interest, since few mechanisms are efficient enough to induce a significant feedback to the gas phase. Methods. We irradiated ice film mixtures made of methanol and carbon dioxide of varying ratios with swift heavy ions in the electronic sputtering regime. We monitored the evolution of the infrared spectra as well as the species released to the gas phase with a mass spectrometer. Methanol (12C) and isotopically labelled 13C-methanol were used to remove any ambiguity on the measured irradiation products. Results. The sputtering of methanol embedded in carbon dioxide ice is an efficient process leading to the ejection of intact methanol in the gas phase. We establish that when methanol is embedded in a carbon-dioxide-rich mantle exposed to cosmic rays, a significant fraction (0.2–0.3 in this work) is sputtered as intact molecules. The sputtered fraction follows the time-dependent bulk composition of the ice mantle, the latter evolving with time due to the radiolysis-induced evolution of the bulk. If methanol is embedded in a carbon dioxide ice matrix, as the analyses of the spectral shape of the CO2 bending mode observations in some lines of sight suggest, the overall methanol sputtering yield is higher than if embedded in a water ice mantle. The sputtering is increased by a factor close to the dominant ice matrix sputtering yield, which is about six times higher for pure carbon dioxide ice when compared to water ice. These experiments are further constraining the cosmic-ray-induced ice mantle sputtering mechanisms important role in the gas-phase release of complex organic molecules from the interstellar solid phase.

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12

Dartois, E., M. Chabot, T. Id Barkach, H. Rothard, B. Augé, A. N. Agnihotri, A. Domaracka, and P. Boduch. "Non-thermal desorption of complex organic molecules." Astronomy & Astrophysics 628 (August 2019): C2. http://dx.doi.org/10.1051/0004-6361/201834787e.

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13

Ohishi, Masatoshi. "Search for complex organic molecules in space." Journal of Physics: Conference Series 728 (July 2016): 052002. http://dx.doi.org/10.1088/1742-6596/728/5/052002.

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14

Abplanalp, Matthew J., Samer Gozem, Anna I. Krylov, Christopher N. Shingledecker, Eric Herbst, and Ralf I. Kaiser. "A study of interstellar aldehydes and enols as tracers of a cosmic ray-driven nonequilibrium synthesis of complex organic molecules." Proceedings of the National Academy of Sciences 113, no. 28 (July 5, 2016): 7727–32. http://dx.doi.org/10.1073/pnas.1604426113.

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Complex organic molecules such as sugars and amides are ubiquitous in star- and planet-forming regions, but their formation mechanisms have remained largely elusive until now. Here we show in a combined experimental, computational, and astrochemical modeling study that interstellar aldehydes and enols like acetaldehyde (CH3CHO) and vinyl alcohol (C2H3OH) act as key tracers of a cosmic-ray-driven nonequilibrium chemistry leading to complex organics even deep within low-temperature interstellar ices at 10 K. Our findings challenge conventional wisdom and define a hitherto poorly characterized reaction class forming complex organic molecules inside interstellar ices before their sublimation in star-forming regions such as SgrB2(N). These processes are of vital importance in initiating a chain of chemical reactions leading eventually to the molecular precursors of biorelevant molecules as planets form in their interstellar nurseries.

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15

Farrow, T., R. A. Taylor, and V. Vedral. "Towards witnessing quantum effects in complex molecules." Faraday Discussions 184 (2015): 183–91. http://dx.doi.org/10.1039/c5fd00101c.

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Whether many-body objects like organic molecules can exhibit full quantum behaviour, including entanglement, is an open fundamental question. We present a generic theoretical protocol for entangling two organic molecules, such as dibenzoterrylene in anthracene. The availability of organic dye molecules with two-level energy structures characterised by sharp and intense emission lines are characteristics that position them favourably as candidates for quantum information processing technologies involving single-photons. Quantum entanglement can in principle be generated between several organic molecules by carefully interfering their photoluminescence spectra. Major milestones have been achieved in the last 10 years showcasing entanglement in diverse systems including ions, cold atoms, superconductors, photons, quantum dots and NV-centres in diamond, but not yet in molecules.

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16

Fayolle, Edith C., Karin I. Öberg, Robin T. Garrod, Ewine F. van Dishoeck, and Suzanne E. Bisschop. "Complex organic molecules in organic-poor massive young stellar objects." Astronomy & Astrophysics 576 (March 25, 2015): A45. http://dx.doi.org/10.1051/0004-6361/201323114.

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17

Filho, Eloi Alves da Silva, Fabricio Uliana, Stêner Romanel Ambrozio, Cleverton Oliveira, Renan Martin, and Arlan da Silva Gonçalves. "COMPUTATIONAL STUDY OF ORGANIC COMPOUNDS – AN APPLICATION FOR LEARNING IN CHEMISTRY." Revista Ifes Ciência 5, no. 1 (November 22, 2019): 257–66. http://dx.doi.org/10.36524/ric.v5i1.293.

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Organic chemistry is a theme not so easy to understand by undergraduating students. The motivation of this work was carried out computational study of three different molecules by molecular modeling using classic and semi-empirical methods besides open-source softwares. The optimized structures were visualized through 3D representations which made the study more understanding. Physical chemistry properties were extracted from all molecules. For the molecule one there was good correlation between the calculation methods. For the molecule two and more complex structures like molecule three and four there was possible influence of steric effect showing that each method is applicable for each study system.

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18

Lee, Tsung-Hsun, Jhen-Hao Li, Wei-Shun Huang, Bin Hu, J. C. A. Huang, Tzung-Fang Guo, and Ten-Chin Wen. "Magnetoconductance responses in organic charge-transfer-complex molecules." Applied Physics Letters 99, no. 7 (August 15, 2011): 073307. http://dx.doi.org/10.1063/1.3627170.

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19

Zeman, Ellen J. "Complex Organic Molecules Found in Interplanetary Dust Particles." Physics Today 47, no. 3 (March 1994): 17–19. http://dx.doi.org/10.1063/1.2808432.

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20

Álvarez-Barcia, S., P. Russ, J. Kästner, and T. Lamberts. "Hydrogen transfer reactions of interstellar complex organic molecules." Monthly Notices of the Royal Astronomical Society 479, no. 2 (June 6, 2018): 2007–15. http://dx.doi.org/10.1093/mnras/sty1478.

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21

Kukhto, A. V. "Luminescence of complex organic molecules upon electron excitation." Journal of Applied Spectroscopy 65, no. 5 (September 1998): 722–38. http://dx.doi.org/10.1007/bf02679844.

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22

Bergner, Jennifer B., Karin I. Öberg, Robin T. Garrod, and Dawn M. Graninger. "Complex Organic Molecules toward Embedded Low-mass Protostars." Astrophysical Journal 841, no. 2 (June 2, 2017): 120. http://dx.doi.org/10.3847/1538-4357/aa72f6.

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23

Cuadrado, S., J. R. Goicoechea, J. Cernicharo, A. Fuente, J. Pety, and B. Tercero. "Complex organic molecules in strongly UV-irradiated gas." Astronomy & Astrophysics 603 (July 2017): A124. http://dx.doi.org/10.1051/0004-6361/201730459.

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24

Philipp, Dean M., Mark A. Watson, Haoyu S. Yu, Thomas B. Steinbrecher, and Art D. Bochevarov. "Quantum chemical pKa prediction for complex organic molecules." International Journal of Quantum Chemistry 118, no. 12 (December 6, 2017): e25561. http://dx.doi.org/10.1002/qua.25561.

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25

Weaver, Susanna L. Widicus, Robin T. Garrod, Jacob C. Laas, and Eric Herbst. "Models of Hot Cores with Complex Molecules." Proceedings of the International Astronomical Union 7, S280 (June 2011): 79–87. http://dx.doi.org/10.1017/s1743921311024884.

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AbstractRecent models of hot cores have incorporated previously-uninvestigated chemical pathways that lead to the formation of complex organic molecules (COMs; i.e. species containing six or more atoms). In addition to the gas-phase ion-molecule reactions long thought to dominate the organic chemistry in these regions, these models now include photodissociation-driven grain surface reaction pathways that can also lead to COMs. Here, simple grain surface ice species photodissociate to form small radicals such as OH, CH3, CH2OH, CH3O, HCO, and NH2. These species become mobile at temperatures above 30 K during the warm-up phase of star formation. Radical-radical addition reactions on grain surfaces can then form an array of COMs that are ejected into the gas phase at higher temperatures. Photodissociation experiments on pure and mixed ices also show that these complex molecules can indeed form from simple species. The molecules predicted to form from this type of chemistry reasonably match the organic inventory observed in high mass hot cores such as Sgr B2(N) and Orion-KL. However, the relative abundances of the observed molecules differ from the predicted values, and also differ between sources. Given this disparity, it remains unclear whether grain surface chemistry governed by photodissociation is the dominant mechanism for the formation of COMs, or whether other unexplored gas-phase reaction pathways could also contribute significantly to their formation. The influence that the physical conditions of the source have on the chemical inventory also remains unclear. Here we overview the chemical pathways for COM formation in hot cores. We also present new modeling results that begin to narrow down the possible routes for production of COMs based on the observed relative abundances of methyl formate (HCOOCH3) and its C2H4O2 structural isomers.

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26

Overman, Larry E. "Molecular rearrangements in the construction of complex molecules." Tetrahedron 65, no. 33 (August 2009): 6432–46. http://dx.doi.org/10.1016/j.tet.2009.05.067.

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27

Rojas-García, O. S., A. I. Gómez-Ruiz, A. Palau, M. T. Orozco-Aguilera, M. Chavez Dagostino, and S. E. Kurtz. "Interstellar Complex Organic Molecules in SiO-traced Massive Outflows." Astrophysical Journal Supplement Series 262, no. 1 (August 19, 2022): 13. http://dx.doi.org/10.3847/1538-4365/ac81cb.

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Abstract The interstellar medium contains dust and gas, in which molecules can proliferate at high densities and in cold conditions. Interstellar complex organic molecules (iCOMs) are C-bearing species that contain at least six atoms. As they are detected in young stellar objects, iCOMs are expected to inhabit early stages of star formation evolution. In this study, we try to determine which iCOMs are present in the outflow component of massive protostars. To do this, we analyzed the morphological extension of blue- and redshifted iCOM emission in a sample of 11 massive protostars employing mapping observations at 1 mm within a ∼1 GHz bandwidth for both the IRAM-30 m and APEX telescopes. We modeled the iCOM emission of the central pointing spectra of our objects using the XCLASS local thermal equilibrium radiative transfer code. We detected the presence of several iCOMs such as CH3OH, 13CH3OH, CH3OCHO, C2H5C15N, and (c-C3H2)CH2. In G034.41+0.24, G327.29-0.58, G328.81+0.63, G333.13-0.43, G340.97-1.02, G351.45+0.66, and G351.77-0.54, the iCOM lines show a faint broad-line profile. Due to the offset peak positions of the blue- and redshifted emission, covering from ∼0.1 to 0.5 pc, these wings are possibly related to movements external to the compact core, such as large-scale low-velocity outflows. We have also established a correlation between the parent iCOM molecule CH3OH and the shock tracer SiO, reinforcing the hypothesis that shock environments provide the conditions to boost the formation of iCOMs via gas-phase reactions.

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28

Veciana, Jaume, and Hiizu Iwamura. "Organic Magnets." MRS Bulletin 25, no. 11 (November 2000): 41–51. http://dx.doi.org/10.1557/mrs2000.223.

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The notion of organic molecular materials showing metallic properties, such as electric conductivity or ferromagnetism, started several decades ago as a mere dream of some members of the chemical community. The goal was to create an assembly of organic molecules or macromolecules containing only light elements (C, H, N, O, S, etc.) and yet possessing the electron/hole mobility or spin alignment that is inherent in typical metals or their oxides and different from the isolated molecular materials. Organic molecular conductors initially were developed during the 1960s, but the first examples of organic molecular magnets took several more decades to be discovered, owing to the more subtle and complex structural and electronic aspects of these materials. The flurry of activity in this field can be traced to the widely held belief that even the most sophisticated properties can be rationally designed by a systematic modification of organic molecular structures. This motivation was further fueled by increased synthetic capabilities, especially for obtaining large organic molecules with suitable structures and topologies, and also by the spectacular progress of supramolecular chemistry for materials development witnessed in recent years. Also noteworthy is the pioneering work performed in the 1960s by several physical organic chemists who unraveled different ways of aligning spins within open-shell molecules (i.e., triplet diradicals, carbenes, etc.), working against nature's tendency to align them in an antiparallel manner. Magnetic interactions between unpaired electrons, located on the singly occupied molecular orbitals (SOMOs) of di- and polyradicals, or between the adjacent open-shell molecules in crystals, are a crucial issue in this evolving field. Thus, depending upon the symmetry, degeneracy,and topological characteristics of SOMOs and also on the mode of arrangement of the molecules in a crystal, the resulting interaction can align the neighboring spins parallel or antiparallel (see the introductory article by Miller and Epstein in this issue of MRS Bulletin).

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29

Nuevo, Michel, George Cooper, John M. Saunders, Christina E. Buffo, and Scott A. Sandford. "Formation of complex organic molecules in astrophysical environments: Sugars and derivatives." Proceedings of the International Astronomical Union 15, S350 (April 2019): 123–26. http://dx.doi.org/10.1017/s1743921319009323.

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AbstractCarbonaceous meteorites contain a large variety of complex organic molecules, including amino acids, nucleobases, sugar derivatives, amphiphiles, and other compounds of astrobiological interest. Photoprocessing of ices condensed on cold grains with ultraviolet (UV) photons was proposed as an efficient way to form such complex organics in astrophysical environments. This hypothesis was confirmed by laboratory experiments simulating photo-irradiation of ices containing H2O, CH3OH, CO, CO2, CH4, H2CO, NH3, HCN, etc., condensed on cold (~10–80 K) substrates. These experiments resulted in the formation of amino acids, nucleobases, sugar derivatives, amphiphilic compounds, and other organics comparable to those identified in carbonaceous meteorites. This work presents results for the formation of sugars, sugar alcohols, sugar acids, and their deoxy variants from the UV irradiation of ices containing H2O and CH3OH in relative proportions 2:1, and their comparison with meteoritic data. The formation mechanisms of these compounds and the astrobiological implications are also discussed.

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30

Steele, A., L. G. Benning, R. Wirth, A. Schreiber, T. Araki, F. M. McCubbin, M. D. Fries, et al. "Organic synthesis associated with serpentinization and carbonation on early Mars." Science 375, no. 6577 (January 14, 2022): 172–77. http://dx.doi.org/10.1126/science.abg7905.

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Abiotic formation of organic molecules Mars rovers have found complex organic molecules in the ancient rocks exposed on the planet’s surface and methane in the modern atmosphere. It is unclear what processes produced these organics, with proposals including both biotic and abiotic sources. Steele et al . analyzed the nanoscale mineralogy of the Mars meteorite ALH 84001 and found evidence of organic synthesis driven by serpentinization and carbonation reactions that occurred during the aqueous alteration of basalt rock by hydrothermal fluids. The results demonstrate that abiotic production of organic molecules operated on Mars 4 billion years ago. —KTS

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31

Molina-Ontoria, Agustín, María Gallego, Luís Echegoyen, Emilio M. Pérez, and Nazario Martín. "Organic solar cells based on bowl-shaped small-molecules." RSC Advances 5, no. 40 (2015): 31541–46. http://dx.doi.org/10.1039/c5ra02073e.

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A supramolecular approach involving bowl-shape molecules as electron donors has been used for the preparation of small-molecule solar cells. The PCE values depend directly on the formation of the supramolecular complex.

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32

Sagan, C., W. R. Thompson, and B. N. Khare. "Titan's Organic Chemistry." Symposium - International Astronomical Union 112 (1985): 107–21. http://dx.doi.org/10.1017/s007418090014642x.

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Voyager discovered nine simple organic molecules in the atmosphere of Titan. Complex organic solids, called tholins, produced by irradiation of simulated Titanian atmosphere are consistent with measured properties of Titan from ultraviolet to microwave frequencies, and are the likely main constituents of the observed red aerosols. The tholins contain many of the organic building blocks central to life on Earth. At least 100 m and possibly kms thickness of complex organics have been produced on Titan during the age of the solar system, and may exist today as submarine deposits beneath an extensive ocean of simple hydrocarbons.

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33

Shaikh, Moniruzzaman, Xinyao Liu, Kasra Amini, Tobias Steinle, and Jens Biegert. "High density molecular jets of complex neutral organic molecules with Tesla valves." Review of Scientific Instruments 92, no. 10 (October 1, 2021): 104103. http://dx.doi.org/10.1063/5.0060904.

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34

Belloche, A., H. S. P. Müller, R. T. Garrod, and K. M. Menten. "Exploring Molecular Complexity with ALMA: Deuterated complex organic molecules in Sgr B2." EAS Publications Series 75-76 (2015): 329–32. http://dx.doi.org/10.1051/eas/1575066.

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35

Sakai, Nami, and Satoshi Yamamoto. "Observations of Complex Molecules in Low-Mass Protostars." Proceedings of the International Astronomical Union 7, S280 (June 2011): 43–52. http://dx.doi.org/10.1017/s1743921311024859.

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AbstractLow-mass star forming regions are rich inventories of complex organic molecules. Furthermore, they show significant chemical diversity even among sources in a similar physical evolutionary stage (i.e. Class 0 sources). One distinct case is the hot corino chemistry characterized by rich existence of saturated complex organic molecules such as HCOOCH3 and C2H5CN, whereas the other is the warm carbon-chain chemistry (WCCC) characterized by extraordinary richness of unsaturated complex organic molecules such as carbon-chain molecules. We here summarize these observational achievements during the last decade, and present a unified picture of carbon chemistry in low-mass protostellar cores. The chemical diversity most likely originates from the source-to-source difference in chemical compositions of grain mantles. In particular, the gas-phase abundance of CH4 evaporated from grain mantles is thought to be a key factor for appearance of WCCC. The origin of the diversity and its evolution to protopranetary disks are discussed.

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36

Ehrenfreund, Pascale, Marco Spaans, and Nils G. Holm. "The evolution of organic matter in space." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 369, no. 1936 (February 13, 2011): 538–54. http://dx.doi.org/10.1098/rsta.2010.0231.

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Carbon, and molecules made from it, have already been observed in the early Universe. During cosmic time, many galaxies undergo intense periods of star formation, during which heavy elements like carbon, oxygen, nitrogen, silicon and iron are produced. Also, many complex molecules, from carbon monoxide to polycyclic aromatic hydrocarbons, are detected in these systems, like they are for our own Galaxy. Interstellar molecular clouds and circumstellar envelopes are factories of complex molecular synthesis. A surprisingly high number of molecules that are used in contemporary biochemistry on the Earth are found in the interstellar medium, planetary atmospheres and surfaces, comets, asteroids and meteorites and interplanetary dust particles. Large quantities of extra-terrestrial material were delivered via comets and asteroids to young planetary surfaces during the heavy bombardment phase. Monitoring the formation and evolution of organic matter in space is crucial in order to determine the prebiotic reservoirs available to the early Earth. It is equally important to reveal abiotic routes to prebiotic molecules in the Earth environments. Materials from both carbon sources (extra-terrestrial and endogenous) may have contributed to biochemical pathways on the Earth leading to life’s origin. The research avenues discussed also guide us to extend our knowledge to other habitable worlds.

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37

Whittet, D. C. B. "Interstellar Dust and the Organic Inventories of Early Solar Systems." Symposium - International Astronomical Union 213 (2004): 163–68. http://dx.doi.org/10.1017/s0074180900193192.

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Interstellar dust grains are vectors for cosmic carbon and other biogenic chemical elements. They deliver carbon to protoplanetary disks in various refractory phases (amorphous, graphitic, etc.), and they are coated with icy mantles that contain organic molecules and water. The nature of the organics present in and on the dust appears to be closely related to physical conditions. Complex molecules may be synthesized when simple ices are irradiated. Astronomical observations show that this occurs in the vicinity of certain massive protostars, but it is not known whether our Solar System formed in such a region. Organic matter does not survive cycling though diffuse regions of interstellar space; any organics delivered to the early Earth must have originated in the parent molecular cloud, or in the solar nebula itself. A key question is thus identified: What was the star-formation environment of the Solar System? Possible constraints are briefly discussed.

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38

Мигович, М,, and В. Кельман. "Photophysical processes at UV irradiation of complex organic molecules." Scientific Herald of Uzhhorod University.Series Physics 35 (June 30, 2014): 156–61. http://dx.doi.org/10.24144/2415-8038.2014.35.156-161.

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39

Neumann, M. A. "Crystal structures of moderately complex organic molecules are predictable." Acta Crystallographica Section A Foundations of Crystallography 63, a1 (August 22, 2007): s37—s38. http://dx.doi.org/10.1107/s0108767307099163.

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40

Neumann, M. A. "Crystal structures of moderately complex organic molecules are predictable." Acta Crystallographica Section A Foundations of Crystallography 64, a1 (August 23, 2008): C205—C206. http://dx.doi.org/10.1107/s0108767308093409.

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41

Vastel, C., C. Ceccarelli, B. Lefloch, and R. Bachiller. "THE ORIGIN OF COMPLEX ORGANIC MOLECULES IN PRESTELLAR CORES." Astrophysical Journal 795, no. 1 (October 10, 2014): L2. http://dx.doi.org/10.1088/2041-8205/795/1/l2.

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42

Lattelais, M., F. Pauzat, Y. Ellinger, and C. Ceccarelli. "INTERSTELLAR COMPLEX ORGANIC MOLECULES AND THE MINIMUM ENERGY PRINCIPLE." Astrophysical Journal 696, no. 2 (April 17, 2009): L133—L136. http://dx.doi.org/10.1088/0004-637x/696/2/l133.

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43

Myrdal, Paul B., and Samuel H. Yalkowsky. "Estimating Pure Component Vapor Pressures of Complex Organic Molecules." Industrial & Engineering Chemistry Research 36, no. 6 (June 1997): 2494–99. http://dx.doi.org/10.1021/ie950242l.

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44

Moulin, C., A. Petit, and J. C. Baccou. "Selective laser photolysis of organic molecules in complex matrices." Journal of Photochemistry and Photobiology A: Chemistry 85, no. 1-2 (January 1995): 165–72. http://dx.doi.org/10.1016/1010-6030(94)03897-4.

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45

MOULIN, C., A. PETIT, J. C. BACCOU, and P. FAUGERAS. "Selective laser photolysis of organic molecules in complex matrices." Le Journal de Physique IV 04, no. C4 (April 1994): C4–715—C4–715. http://dx.doi.org/10.1051/jp4:19944193.

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46

Puzzarini, Cristina. "Astronomical complex organic molecules: Quantum chemistry meets rotational spectroscopy." International Journal of Quantum Chemistry 117, no. 2 (September 12, 2016): 129–38. http://dx.doi.org/10.1002/qua.25284.

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47

Hanson, J. R. "Transition metals in the synthesis of complex organic molecules." Journal of Organometallic Chemistry 489, no. 1-2 (March 1995): C92. http://dx.doi.org/10.1016/0022-328x(95)90799-k.

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48

Terwisscha van Scheltinga, J., N. F. W. Ligterink, A. C. A. Boogert, E. F. van Dishoeck, and H. Linnartz. "Infrared spectra of complex organic molecules in astronomically relevant ice matrices." Astronomy & Astrophysics 611 (March 2018): A35. http://dx.doi.org/10.1051/0004-6361/201731998.

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Context. The number of identified complex organic molecules (COMs) in inter- and circumstellar gas-phase environments is steadily increasing. Recent laboratory studies show that many such species form on icy dust grains. At present only smaller molecular species have been directly identified in space in the solid state. Accurate spectroscopic laboratory data of frozen COMs, embedded in ice matrices containing ingredients related to their formation scheme, are still largely lacking.Aim. This work provides infrared reference spectra of acetaldehyde (CH3CHO), ethanol (CH3CH2OH), and dimethyl ether (CH3OCH3) recorded in a variety of ice environments and for astronomically relevant temperatures, as needed to guide or interpret astronomical observations, specifically for upcoming James Webb Space Telescope observations.Methods. Fourier transform transmission spectroscopy (500–4000 cm−1/20–2.5 μm, 1.0 cm−1 resolution) was used to investigate solid acetaldehyde, ethanol and dimethyl ether, pure or mixed with water, CO, methanol, or CO:methanol. These species were deposited on a cryogenically cooled infrared transmissive window at 15 K. A heating ramp was applied, during which IR spectra were recorded until all ice constituents were thermally desorbed.Results. We present a large number of reference spectra that can be compared with astronomical data. Accurate band positions and band widths are provided for the studied ice mixtures and temperatures. Special efforts have been put into those bands of each molecule that are best suited for identification. For acetaldehyde the 7.427 and 5.803 μm bands are recommended, for ethanol the 11.36 and 7.240 μm bands are good candidates, and for dimethyl ether bands at 9.141 and 8.011 μm can be used. All spectra are publicly available in the Leiden Database for Ice.

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49

Bottinelli, Sandrine, Adwin C. A. Boogert, Ewine F. van Dishoeck, Martha Beckwith, Jordy Bouwman, Harold Linnartz, and Karin I. Öberg. "Precursors of complex organic molecules: NH3 and CH3OH in the ices surrounding low-mass protostars." Proceedings of the International Astronomical Union 4, S251 (February 2008): 105–10. http://dx.doi.org/10.1017/s1743921308021285.

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AbstractNH3 and CH3OH are key molecules in the chemical networks leading to the formation of complex N- and O-bearing organic molecules. However, despite a number of recent studies, there is still a lot to learn about their abundances in the solid state and how they relate to those of other N/O-bearing organic molecules or to NH3 and CH3OH abundances in the gas phase. This is particularly true in the case of low-mass young stellar objects (YSOs), for which only the recent advent of the Spitzer Space Telescope has allowed high sensitivity observations of the ices in their enveloppes. We present a combined study of Spitzer data (obtained within the Legacy program “From Molecular Cores to Planet-Forming Disks”, c2d) and laboratory spectra, leading to the detections of NH3 and CH3OH in the ices of low-mass protostars. We investigate correlations with other ice features and conclude with prospects on further studies linking these two precursors of complex organic molecules with their gas-phase products.

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50

Terwisscha van Scheltinga, J., N. F. W. Ligterink, A. C. A. Boogert, E. F. van Dishoeck, and H. Linnartz. "Infrared spectra of complex organic molecules in astronomically relevant ice matrices." Proceedings of the International Astronomical Union 15, S350 (April 2019): 356–57. http://dx.doi.org/10.1017/s1743921319008780.

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Анотація:

AbstractThe identification of complex organic molecules, COMs, in inter- and circumstellar gas phase environments is steadily increasing. The formation of such COMs takes largely place on the icy dust grains, as has been shown in recent laboratory studies. Until now solid state features of smaller molecular species have been directly identified in these environments. The presented work on acetaldehyde (CH3CHO), ethanol (CH3CH2OH), and dimethyl ether (CH3OCH3) in different astronomically relevant ice environments and for temperatures in the range 15 to 160 Kelvin, provides the necessary tools to guide or interpret astronomical observations, specifically for upcoming James Webb Space Telescope observations.

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