Joanna V. Egan*, Alexander D. James and John M. C. Plane*,
{"title":"Laboratory Measurements of Ferric Chloride (FeCl3) under Venusian Conditions","authors":"Joanna V. Egan*, Alexander D. James and John M. C. Plane*, ","doi":"10.1021/acsearthspacechem.5c00132","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.5c00132","url":null,"abstract":"<p >Ferric chloride (FeCl<sub>3</sub>) in sulfuric acid cloud droplets has been proposed to explain the inhomogeneous near-ultraviolet (UV) absorption visible at the Venusian cloud tops. However, the absorption spectrum of FeCl<sub>3</sub> in concentrated sulfuric acid does not appear to have been measured previously; here we report measurements under appropriate conditions of temperature and H<sub>2</sub>SO<sub>4</sub>/H<sub>2</sub>O solution strengths. The choice of solvent has a significant effect on the measured spectrum. The reaction of FeCl<sub>3</sub> in aqueous H<sub>2</sub>SO<sub>4</sub> to form ferric sulfate (Fe<sub>2</sub>(SO<sub>4</sub>)<sub>3</sub>) was shown to be suppressed by adding HCl to the solution (as would occur in the Venusian atmosphere). The FeCl<sub>3</sub> spectrum in sulfuric acid is shown to be in good agreement with observations of the unknown absorber in Venus’ atmosphere. The presence of Fe<sub>2</sub>(SO<sub>4</sub>)<sub>3</sub>, which absorbs strongly below 320 nm, should be considered when reconstructing Venusian spectra to avoid misattribution of absorption in this spectral region to SO<sub>2</sub>, potentially leading to an overestimation of the SO<sub>2</sub> cloud top concentrations.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 8","pages":"2127–2136"},"PeriodicalIF":2.9,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acsearthspacechem.5c00132","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144878100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Catalytic Effects on Aldose Formation by γ-ray-Induced Formose-Type Reactions in Meteorite Parent Bodies","authors":"Shunpei Abe, Naoki Hirakawa, Kazuya Toyoshima, Isao Yoda, Kensei Kobayashi and Yoko Kebukawa*, ","doi":"10.1021/acsearthspacechem.5c00119","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.5c00119","url":null,"abstract":"<p >The formose-type reaction is widely regarded as a key process in the formation of sugars including ribose, a component of RNA, which is essential for life. Aqueous alteration in meteorite parent bodies constitutes one of the potential extraterrestrial environments wherein formose-type reactions could have occurred. The reaction could have been driven by ionizing radiation from radionuclide decay and the decay heat. Furthermore, this heating process may have released metal ions from the meteorite minerals, further enhancing the reaction. While hydrothermal experiments have been conducted to simulate such environments, the role of radiation in this process has rarely been considered. However, we have shown that radiation plays a key role in studying the prebiotic synthesis of sugars during the early stages of aqueous alteration of meteorite parent bodies. To investigate the effects of catalysts under irradiation, meteorite parent body simulants were irradiated with γ-rays at room temperature, with ammonia, calcium hydroxide, glycolaldehyde, and olivine serving as catalysts, and the production of aldoses was examined. As a result, these catalysts enhance aldose production under γ-ray irradiation. However, the effects of calcium hydroxide and olivine were found to be limited, potentially attributable to their lower solubility at room temperature. In contrast, ammonia and glycolaldehyde showed more significant effects. This observation indicates that in the early stages of aqueous alteration of meteorite parent bodies, where radiation such as γ-rays is likely to be the predominant energy source, dissolved catalysts play a more important role compared to solid catalysts.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 8","pages":"2115–2126"},"PeriodicalIF":2.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acsearthspacechem.5c00119","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144878098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wenhui Zhang, Shikai Zhao and Anthony S. Serianni*,
{"title":"Pathways to Carbohydrates on Prebiotic Earth: Hydrogen Cyanide as a Substrate and Catalyst in a Reducing Environment","authors":"Wenhui Zhang, Shikai Zhao and Anthony S. Serianni*, ","doi":"10.1021/acsearthspacechem.5c00097","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.5c00097","url":null,"abstract":"<p >We present alternate chemical routes for the production of simple sugars on prebiotic Earth that do not involve the formose reaction, whose mechanism of initiation involving the self-condensation of two formaldehyde electrophiles remains unclear. We show that HCN is the only carbon-containing prebiotic molecule required for the production of short- and medium-chain aldoses and ketoses, wherein HCN serves as either a reactant or catalyst. <i>In situ</i> generation of H<sub>2</sub> from the decomposition of formic acid, produced from HCN hydrolysis, supports the two-electron reduction of cyanohydrins to imines, catalyzed by heavy or transition metals provided by asteroid or meteorite collisions with prebiotic Earth and subsequent imine hydrolysis to give aldehydic functionalities. Experimental evidence is provided to support some of the proposed pathways, including the control of glycolaldehyde self-condensation in the presence of cyanide ions to preferentially give C<sub>5</sub> aldononitriles (cyanohydrins) and cyclic imido-1,4-lactones, both precursors to aldopentoses. Molybdate-catalyzed aldose epimerization is discussed as a chemical progenitor to the transketolase reaction of the pentose phosphate pathway, whose mechanism of action may be more complex than presently understood.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 8","pages":"2077–2091"},"PeriodicalIF":2.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144878095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hyunwoo Lee*, Wonhee Lee, Mi Jung Lee, Yongmoon Lee, Jonghoon Park, Hyerin Cha, Naoto Takahata, Yuji Sano and Tobias P. Fischer,
{"title":"Diffuse Soil Degassing in Hydrothermal Areas of Mt. Melbourne, Antarctica: Insights for the Understanding of Cryovolcanism on Earth","authors":"Hyunwoo Lee*, Wonhee Lee, Mi Jung Lee, Yongmoon Lee, Jonghoon Park, Hyerin Cha, Naoto Takahata, Yuji Sano and Tobias P. Fischer, ","doi":"10.1021/acsearthspacechem.5c00099","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.5c00099","url":null,"abstract":"<p >Cryovolcanism is a phenomenon reported in dwarf planets and satellites in the solar system and is characterized by the eruptions of volatiles under low-temperature conditions. However, there are clearly limitations to understanding it fully from observations far from Earth. From this point of view, Antarctica is one of the most extreme environments on Earth and is a very important region for modeling the extraterrestrial environment. Here, we report a maximum soil CO<sub>2</sub> flux value of 6120 g m<sup>–2</sup> d<sup>–1</sup> and a total CO<sub>2</sub> output of 8355 t d<sup>–1</sup> from the hydrothermal environment (up to 57.6 °C) of Mt. Melbourne, an active volcano located in Antarctica. In addition, fumarolic gases have δ<sup>13</sup>C values of −13.9 to −4.2‰ with CO<sub>2</sub> concentrations of 21.2–36.2 vol %. The corrected helium isotope ratios (Rc/Ra) of the gases are up to 2.21, indicating the magma degassing of Mt. Melbourne. However, hydrogen and oxygen isotopes of the ice samples inside the ice caves and ice towers in the hydrothermal region, similar to their surroundings, suggest that they are of largely atmospheric origin. Nevertheless, the circulated water caused hydrothermal alteration, producing minerals such as kaolinite and gibbsite, which greatly affected the moss habitat and microbial distribution of small greenhouse systems. Thus, the observations in this Antarctic hydrothermal system could potentially provide clues about extraterrestrial biological activity through cryovolcanism.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 8","pages":"2092–2101"},"PeriodicalIF":2.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144878099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Katerina Slavicinska*, Charlotte Coone, Bryce Benz, Harold Linnartz, A. C. Adwin Boogert and Ko-Ju Chuang,
{"title":"Laboratory Infrared Spectra and Band Strengths of Carbonyl Sulfide (OCS) in CH3OH- and CO-Rich Ice Mixtures for Analyzing Interstellar Ice Observations","authors":"Katerina Slavicinska*, Charlotte Coone, Bryce Benz, Harold Linnartz, A. C. Adwin Boogert and Ko-Ju Chuang, ","doi":"10.1021/acsearthspacechem.5c00134","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.5c00134","url":null,"abstract":"<p >Carbonyl sulfide (OCS) is currently the only securely detected sulfur-bearing species in interstellar ices, making it an ideal window into solid-state sulfur chemistry in dense star-forming regions. Previous astronomical observations of the OCS asymmetric stretching mode (ν<sub>3</sub>) at ∼2040 cm<sup>–1</sup> (∼4.9 μm) demonstrate that interstellar OCS may be embedded in CH<sub>3</sub>OH-rich ices, indicating that OCS likely forms in the coldest, densest parts of star-forming regions where catastrophic CO freezeout occurs. However, a significant portion of the OCS ice observations cannot be fit with binary OCS:CH<sub>3</sub>OH laboratory ice mixtures alone, suggesting a greater degree of chemical complexity in the local ice environment. With this work, we aim to aid future studies of the abundance, physicochemical environment, and evolutionary history of interstellar OCS ice, now enabled for many more interstellar environments by the <i>James Webb</i> Space Telescope. We provide a library of new laboratory IR transmission spectra of the tetrahedron of the OCS in CH<sub>3</sub>OH- and CO-rich ice mixtures, some of which also include H<sub>2</sub>S and H<sub>2</sub>O. Of these new spectra, the tertiary OCS:CO:CH<sub>3</sub>OH ice mixtures provide the best fits to observations of high-mass protostars, providing further support for the hypothesis that the atom of the OCS forms with CH<sub>3</sub>OH, possibly via chemical pathways involving frozen-out CO. We calculate apparent band strengths of the ν<sub>3</sub> mode in the OCS:CH<sub>3</sub>OH and the OCS:CO:CH<sub>3</sub>OH ice mixtures. The derived values are consistent (within uncertainties) with the apparent band strength of the feature in pure OCS ice, 1.2 × 10<sup>–16</sup> cm molec<sup>–1</sup>. We therefore recommend using this value when quantifying interstellar OCS ice column densities.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 8","pages":"2148–2158"},"PeriodicalIF":2.9,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acsearthspacechem.5c00134","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144878097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Modeling SOA Formation from Monocyclic, Bicyclic, and Branched-Cyclic Alkanes","authors":"Azad Madhu, and , Myoseon Jang*, ","doi":"10.1021/acsearthspacechem.4c00380","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00380","url":null,"abstract":"<p >Cycloalkanes, which represent a significant proportion of hydrocarbons released through fuel evaporation and exhaust, produce considerable amounts of secondary organic aerosol (SOA). However, cycloalkanes vary in the number of rings and alkyl branch lengths, leading to high complexity in SOA predictions. In this study, the Unified Partitioning Aerosol Phase Reaction (UNIPAR) model is extended to predict SOA formation via multiphase reactions of cyclohexane, decalin, and various branched cyclohexanes. UNIPAR employs a lumped product distribution, originating from an explicit gas mechanism, to process multiphase partitioning and in-particle chemistry for SOA formation. The product distributions of cyclohexane and decalin are created using explicit oxidation mechanisms. Product distributions of alkyl-branched cyclohexanes are created as a composite of those of cyclohexane and linear alkanes. UNIPAR is applied to predict SOA formation for cyclohexane, decalin, butylcyclohexane, and octylcyclohexane, under various NO<sub><i>x</i></sub> levels and seed conditions, and compared to chamber data. Cyclohexane and decalin SOA formation occurs exclusively through particle-phase reactions due to ring-opening aldehydic products. When the NO<sub><i>x</i></sub> level (HC ppbC/NO<sub><i>x</i></sub> ppb) = 3 at given conditions, the oligomeric SOA fraction represents 99.8, 82.2, and 1.0% of mass formed from decalin, butylcyclohexane, and <i>n</i>-decane, respectively. Except cyclohexane, SOA yields of cyclic alkanes are insensitive to seed types. With increasing alkyl branch length, cycloalkanes have increased SOA yields, and their SOA formation behaves more similarly to linear alkanes. Due to insensitivity to seed and NO<sub><i>x</i></sub> conditions, temperature is the key environmental parameter influencing the SOA yields of large cyclic alkanes.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 8","pages":"1964–1977"},"PeriodicalIF":2.9,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144878096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"","authors":"Moshammat Mijjum*, and , Marissa M. Tremblay, ","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 7","pages":"XXX-XXX XXX-XXX"},"PeriodicalIF":2.9,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acsearthspacechem.5c00112","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144640931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lagamawwa Hipparagi, Raksha Umesh and Nanishankar V. Harohally*,
{"title":"","authors":"Lagamawwa Hipparagi, Raksha Umesh and Nanishankar V. Harohally*, ","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 7","pages":"XXX-XXX XXX-XXX"},"PeriodicalIF":2.9,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acsearthspacechem.5c00085","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144640932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"","authors":"Kevin Fleming, and , Elfi Kraka*, ","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 7","pages":"XXX-XXX XXX-XXX"},"PeriodicalIF":2.9,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acsearthspacechem.5c00083","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144640937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sahar Jannesarahmadi*, Milad Aminzadeh*, Rainer Helmig, Dani Or, Bastian Oesterle and Nima Shokri*,
{"title":"","authors":"Sahar Jannesarahmadi*, Milad Aminzadeh*, Rainer Helmig, Dani Or, Bastian Oesterle and Nima Shokri*, ","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 7","pages":"XXX-XXX XXX-XXX"},"PeriodicalIF":2.9,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acsearthspacechem.5c00130","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144640936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}