ACS Earth and Space Chemistry最新文献

{"title":"A Brief History of (Urban) Grime","authors":"D. James Donaldson*,&nbsp;","doi":"10.1021/acsearthspacechem.4c0034510.1021/acsearthspacechem.4c00345","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00345https://doi.org/10.1021/acsearthspacechem.4c00345","url":null,"abstract":"<p >Surfaces exposed to outdoor and even indoor environments, especially in urban settings, develop a coating comprised of chemical compounds deposited from the overlying atmosphere and products of reactions occurring within this coating. Early work recognized the potential of this coating to reflect the local atmospheric concentrations of pollutants. More recently, the potential of such coatings (“urban grime”) to participate in active exchange of important atmospheric oxidants and their precursors has been explored. Here, I will present my perspective on the history of urban grime chemistry studies and where the future may lie in these.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 2","pages":"201–206 201–206"},"PeriodicalIF":2.9,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444060","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":"Alpine Mountain’s Ice Core Records of Dicarboxylic Acids, ω-Oxocarboxylic Acids, and α-Dicarbonyls from Southern Alaska Since 1665 to the Present","authors":"Ambarish Pokhrel,&nbsp;Bhagawati Kunwar,&nbsp;Kimitaka Kawamura* and Sumito Matoba,&nbsp;","doi":"10.1021/acsearthspacechem.4c0033910.1021/acsearthspacechem.4c00339","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00339https://doi.org/10.1021/acsearthspacechem.4c00339","url":null,"abstract":"<p >Ice cores can provide insights into the paleogeochemical cycle and allow us to determine how and why geochemical cycles changed in the past. By understanding how the paleogeochemical cycle changed in the past, we are able to improve predictions of how climate will change in the future. The sensitivity of atmospheric oxidizing capability can be reflected in a homologous series of normal (C₂–C₁₁), branched chain (iC₄–iC₆), unsaturated, multifunctional structures of diacids, together with ω-oxoacids (ωC₂–ωC₉) and α-dicarbonyls (glyoxal and methylglyoxal). We analyze the Alaskan ice core (180 m long, 343 years, 30 species) to understand the historical changes of water-soluble organic aerosols transported over the Aurora Peak facing the Gulf of Alaska. We found a predominance of oxalic acid (C₂), followed by adipic (C₆) and succinic (C₄) acids. Interestingly, similar concentration levels are recorded for 9-oxononanoic (ωC₉), 4-oxobutanoic (ωC₄), and glyoxylic acids (ωC₂). Such molecular distributions are different from those of continental and marine aerosols in mid-latitudes. These polar compounds are likely formed by atmospheric oxidation of unsaturated fatty acids (e.g., C_18:1) and isoprene, which are emitted from the lower latitudes of the northern North Pacific rim (NPR). The concentration ratios of C₃/C₄ and those of other species, which are connected to the atmospheric oxidizing capability of the Northern Hemisphere, exhibit associations with a multidecadal cycle of climate oscillations and periods of the primary and secondary sources. Multidecadal variations of C₃/C₄ ratios may be coupled with sea ice retreat and advance in the Bering Sea and Gulf of Alaska, where the Aleutian Low is significant in the NPR.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 2","pages":"369–381 369–381"},"PeriodicalIF":2.9,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444107","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":"A Brief History of (Urban) Grime.","authors":"D James Donaldson","doi":"10.1021/acsearthspacechem.4c00345","DOIUrl":"10.1021/acsearthspacechem.4c00345","url":null,"abstract":"<p><p>Surfaces exposed to outdoor and even indoor environments, especially in urban settings, develop a coating comprised of chemical compounds deposited from the overlying atmosphere and products of reactions occurring within this coating. Early work recognized the potential of this coating to reflect the local atmospheric concentrations of pollutants. More recently, the potential of such coatings (\"urban grime\") to participate in active exchange of important atmospheric oxidants and their precursors has been explored. Here, I will present my perspective on the history of urban grime chemistry studies and where the future may lie in these.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 2","pages":"201-206"},"PeriodicalIF":2.9,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11849682/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143497480","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":"Formation and Stability of the Propionitrile:Acetylene Co-Crystal Under Titan-Relevant Conditions","authors":"Ellen C. Czaplinski*,&nbsp;Tuan H. Vu,&nbsp;Helen Maynard-Casely,&nbsp;Courtney Ennis,&nbsp;Morgan L. Cable,&nbsp;Michael J. Malaska and Robert Hodyss,&nbsp;","doi":"10.1021/acsearthspacechem.4c0026210.1021/acsearthspacechem.4c00262","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00262https://doi.org/10.1021/acsearthspacechem.4c00262","url":null,"abstract":"<p >Propionitrile (also known as ethyl cyanide, CH₃CH₂CN) and acetylene (C₂H₂) are two organic molecules that have been detected in Titan’s atmosphere. Over time, they may interact with each other as they are transported to Titan’s surface. We sought to determine if any reactions or associations such as co-crystal formation might occur between the two molecules. Using micro-Raman spectroscopy, we characterized band shifts, new bands, and morphological changes, which are characteristic of co-crystal formation. We found that the propionitrile:acetylene co-crystal forms within minutes at 90 K and is stable from 90 to 160 K. A cryogenic powder X-ray diffraction study confirms co-crystal formation at 90 K and indexes to a monoclinic unit cell, <i>P</i>2₁/<i>a</i>. A thermal expansion study between 90 and 140 K indicates that the co-crystal exhibits anisotropic thermal expansion, with a limited change in the <i>b</i> axis over the temperature range. This information gives insight into the preferred form of propionitrile:acetylene and the nature of these molecular interactions under Titan-relevant conditions. We discuss broader implications of the propionitrile:acetylene co-crystal’s participation in forming Titan’s geologic features such as the karstic, labyrinth terrain. Additionally, co-crystals that include acetylene as a coformer may provide a source of energy for acetylenotrophs to harness, should putative life exist on Titan’s surface or in the subsurface. The Dragonfly mission to Titan will explore the nature and distribution of Titan’s organics at the surface; thus, characterizing these organics in the laboratory before surface operations will inform the likely phases Dragonfly may encounter and support data analysis and interpretation of this exciting mission.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 2","pages":"253–264 253–264"},"PeriodicalIF":2.9,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsearthspacechem.4c00262","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444063","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":"Oxidation and Mobilization of Tc-99 Reduced Phases by a Mn(III)–Pyrophosphate Aqueous Complex under Anoxic Conditions: Implications for Remediation of a Risk-Driving Radionuclide","authors":"Jordan Stanberry,&nbsp;Kyle Morgan,&nbsp;Ian Russell,&nbsp;Zachary Ronchetti,&nbsp;Thomas Carroll and Vasileios Anagnostopoulos*,&nbsp;","doi":"10.1021/acsearthspacechem.4c0027410.1021/acsearthspacechem.4c00274","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00274https://doi.org/10.1021/acsearthspacechem.4c00274","url":null,"abstract":"<p >The environmental fate of technetium-99 is tied to its oxidation state. Under oxidizing conditions, Tc-99 predominates as the Tc(VII)O₄^– anion, which exhibits high solubility and is precluded from sorption to mineral surfaces, making it highly mobile in the environment. Under reducing conditions, Tc-99 predominates as Tc(IV) [Tc(IV)O₂, Tc(IV)₂S₇, or Tc(IV)-bearing mineral phases, e.g., Tc(IV) incorporation into iron oxides], which shows low solubility. There has been significant interest in developing reductive immobilization strategies for Tc-99, particularly in anoxic environments where Tc(IV) is conventionally assumed to be stable. However, O₂ is not the only common environmental oxidant. Many high-valent manganese species are prolific in anoxic environments, and they can create localized oxidizing conditions in otherwise reducing environments. Our work aims to bridge the knowledge gap on the remobilization of Tc(IV) species under the conditions mentioned, by studying the oxidation of Tc(IV) by a Mn(III)–pyrophosphate complex. Mn(III)–ligand complexes in particular have been overlooked due to the assumption that Mn(III) will be disproportionate in aqueous systems. In this work, the Mn(III)–pyrophosphate complex rapidly oxidized Tc(IV) to Tc(VII) in the absence of oxygen, resulting in dissolution and release of Tc-99 to the aqueous phase. This work presents novel information about the redox interface chemistry of Tc-99, which is crucial to developing effective remediation methods.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 2","pages":"277–287 277–287"},"PeriodicalIF":2.9,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444075","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":"Formation and Stability of the Propionitrile:Acetylene Co-Crystal Under Titan-Relevant Conditions.","authors":"Ellen C Czaplinski, Tuan H Vu, Helen Maynard-Casely, Courtney Ennis, Morgan L Cable, Michael J Malaska, Robert Hodyss","doi":"10.1021/acsearthspacechem.4c00262","DOIUrl":"10.1021/acsearthspacechem.4c00262","url":null,"abstract":"<p><p>Propionitrile (also known as ethyl cyanide, CH₃CH₂CN) and acetylene (C₂H₂) are two organic molecules that have been detected in Titan's atmosphere. Over time, they may interact with each other as they are transported to Titan's surface. We sought to determine if any reactions or associations such as co-crystal formation might occur between the two molecules. Using micro-Raman spectroscopy, we characterized band shifts, new bands, and morphological changes, which are characteristic of co-crystal formation. We found that the propionitrile:acetylene co-crystal forms within minutes at 90 K and is stable from 90 to 160 K. A cryogenic powder X-ray diffraction study confirms co-crystal formation at 90 K and indexes to a monoclinic unit cell, <i>P</i>2₁/<i>a</i>. A thermal expansion study between 90 and 140 K indicates that the co-crystal exhibits anisotropic thermal expansion, with a limited change in the <i>b</i> axis over the temperature range. This information gives insight into the preferred form of propionitrile:acetylene and the nature of these molecular interactions under Titan-relevant conditions. We discuss broader implications of the propionitrile:acetylene co-crystal's participation in forming Titan's geologic features such as the karstic, labyrinth terrain. Additionally, co-crystals that include acetylene as a coformer may provide a source of energy for acetylenotrophs to harness, should putative life exist on Titan's surface or in the subsurface. The Dragonfly mission to Titan will explore the nature and distribution of Titan's organics at the surface; thus, characterizing these organics in the laboratory before surface operations will inform the likely phases Dragonfly may encounter and support data analysis and interpretation of this exciting mission.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 2","pages":"253-264"},"PeriodicalIF":2.9,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11849028/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143497500","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":"Multigeneration Chemistry in Secondary Organic Aerosol Formation from Nitrate Radical Oxidation of Isoprene.","authors":"Tianchang Xu, Masayuki Takeuchi, Jean C Rivera-Rios, Nga L Ng","doi":"10.1021/acsearthspacechem.4c00417","DOIUrl":"10.1021/acsearthspacechem.4c00417","url":null,"abstract":"&lt;p&gt;&lt;p&gt;The nitrate radical (NO&lt;sub&gt;3&lt;/sub&gt;) oxidation of isoprene is an important contributor to secondary organic aerosol (SOA). Isoprene has two double bonds which allow for multigeneration oxidation to occur. The effects of multigeneration chemistry on the gas- and particle-phase product distributions of the isoprene + NO&lt;sub&gt;3&lt;/sub&gt; system are not fully understood. In this study, we conduct chamber experiments by varying the ratio of N&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; (precursor of NO&lt;sub&gt;3&lt;/sub&gt;) to isoprene concentration from 1:1 to 14:1 to investigate the formation of products in both phases under different oxidation levels. Multigeneration chemistry leads to the formation of gas-phase products which then partition into particle phase depending on the product volatility; first-generation products (15-36% of total SOA) such as C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;9&lt;/sub&gt;NO&lt;sub&gt;5&lt;/sub&gt; and C&lt;sub&gt;10&lt;/sub&gt;H&lt;sub&gt;16&lt;/sub&gt;N&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;9&lt;/sub&gt; have volatility (&lt;i&gt;log&lt;sub&gt;10&lt;/sub&gt;C*&lt;/i&gt; = 1.0-3.0 using the partitioning method and &lt;i&gt;log&lt;sub&gt;10&lt;/sub&gt;C*&lt;/i&gt; = 2.6-4.5 using the formula method) 1-5 orders of magnitude higher than second-generation products (37-57% of total SOA, &lt;i&gt;log&lt;sub&gt;10&lt;/sub&gt;C*&lt;/i&gt; = -0.8-2.1 using the partitioning method and &lt;i&gt;log&lt;sub&gt;10&lt;/sub&gt;C*&lt;/i&gt; = -3.7-1.8 using the formula method) such as C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;8,10&lt;/sub&gt;N&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;8&lt;/sub&gt;, C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;9&lt;/sub&gt;N&lt;sub&gt;3&lt;/sub&gt;O&lt;sub&gt;10&lt;/sub&gt;, and C&lt;sub&gt;10&lt;/sub&gt;H&lt;sub&gt;17&lt;/sub&gt;N&lt;sub&gt;3&lt;/sub&gt;O&lt;sub&gt;13&lt;/sub&gt;. The fast reaction rate constants of first-generation products (estimated to be on the order of 10&lt;sup&gt;-13&lt;/sup&gt; cm&lt;sup&gt;3&lt;/sup&gt; molecules&lt;sup&gt;-1&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt; at 295 K) and the lower volatility of second-generation products result in increased SOA yields when NO&lt;sub&gt;3&lt;/sub&gt; availability increases and multigeneration chemistry is enhanced. Specifically, an increase of up to 300% in SOA yield is observed when the N&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt;/isoprene ratio increases from 1:1 to 3:1; from 5.7% (organic aerosol mass concentration, Δ&lt;i&gt;M&lt;/i&gt; &lt;sub&gt;o&lt;/sub&gt; = 4.2 μg/m&lt;sup&gt;3&lt;/sup&gt;) to 16.3% (Δ&lt;i&gt;M&lt;/i&gt; &lt;sub&gt;o&lt;/sub&gt; = 11.9 μg/m&lt;sup&gt;3&lt;/sup&gt;) when the reacted isoprene concentration is 25 ppb and from 3.1% (Δ&lt;i&gt;M&lt;/i&gt; &lt;sub&gt;o&lt;/sub&gt; = 1.2 μg/m&lt;sup&gt;3&lt;/sup&gt;) to 12.4% (Δ&lt;i&gt;M&lt;/i&gt; &lt;sub&gt;o&lt;/sub&gt; = 5.4 μg/m&lt;sup&gt;3&lt;/sup&gt;) when the reacted isoprene concentration is 15 ppb. The maximum SOA yield occurs when the N&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt;/isoprene ratio is greater than or equal to 3:1 as a combined result of multigeneration chemistry and peroxy radicals (RO&lt;sub&gt;2&lt;/sub&gt;) fate. We encourage future studies to consider both factors, which can vary under different laboratory and ambient conditions, when comparing SOA yields to better understand any differences observed. Our results highlight that multigeneration chemistry and the updated parameters including reaction rate constants and volatility distribution of products should be considered to enable a more comprehensive representation and prediction of SOA formation fr","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 2","pages":"411-423"},"PeriodicalIF":2.9,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11849032/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143497547","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":"Multigeneration Chemistry in Secondary Organic Aerosol Formation from Nitrate Radical Oxidation of Isoprene","authors":"Tianchang Xu,&nbsp;Masayuki Takeuchi,&nbsp;Jean C. Rivera-Rios and Nga L. Ng*,&nbsp;","doi":"10.1021/acsearthspacechem.4c0041710.1021/acsearthspacechem.4c00417","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00417https://doi.org/10.1021/acsearthspacechem.4c00417","url":null,"abstract":"&lt;p &gt;The nitrate radical (NO&lt;sub&gt;3&lt;/sub&gt;) oxidation of isoprene is an important contributor to secondary organic aerosol (SOA). Isoprene has two double bonds which allow for multigeneration oxidation to occur. The effects of multigeneration chemistry on the gas- and particle-phase product distributions of the isoprene + NO&lt;sub&gt;3&lt;/sub&gt; system are not fully understood. In this study, we conduct chamber experiments by varying the ratio of N&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; (precursor of NO&lt;sub&gt;3&lt;/sub&gt;) to isoprene concentration from 1:1 to 14:1 to investigate the formation of products in both phases under different oxidation levels. Multigeneration chemistry leads to the formation of gas-phase products which then partition into particle phase depending on the product volatility; first-generation products (15–36% of total SOA) such as C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;9&lt;/sub&gt;NO&lt;sub&gt;5&lt;/sub&gt; and C&lt;sub&gt;10&lt;/sub&gt;H&lt;sub&gt;16&lt;/sub&gt;N&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;9&lt;/sub&gt; have volatility (&lt;i&gt;log&lt;sub&gt;10&lt;/sub&gt;C*&lt;/i&gt; = 1.0–3.0 using the partitioning method and &lt;i&gt;log&lt;sub&gt;10&lt;/sub&gt;C*&lt;/i&gt; = 2.6–4.5 using the formula method) 1–5 orders of magnitude higher than second-generation products (37–57% of total SOA, &lt;i&gt;log&lt;sub&gt;10&lt;/sub&gt;C*&lt;/i&gt; = −0.8–2.1 using the partitioning method and &lt;i&gt;log&lt;sub&gt;10&lt;/sub&gt;C*&lt;/i&gt; = −3.7–1.8 using the formula method) such as C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;8,10&lt;/sub&gt;N&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;8&lt;/sub&gt;, C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;9&lt;/sub&gt;N&lt;sub&gt;3&lt;/sub&gt;O&lt;sub&gt;10&lt;/sub&gt;, and C&lt;sub&gt;10&lt;/sub&gt;H&lt;sub&gt;17&lt;/sub&gt;N&lt;sub&gt;3&lt;/sub&gt;O&lt;sub&gt;13&lt;/sub&gt;. The fast reaction rate constants of first-generation products (estimated to be on the order of 10&lt;sup&gt;–13&lt;/sup&gt; cm&lt;sup&gt;3&lt;/sup&gt; molecules&lt;sup&gt;–1&lt;/sup&gt; s&lt;sup&gt;–1&lt;/sup&gt; at 295 K) and the lower volatility of second-generation products result in increased SOA yields when NO&lt;sub&gt;3&lt;/sub&gt; availability increases and multigeneration chemistry is enhanced. Specifically, an increase of up to 300% in SOA yield is observed when the N&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt;/isoprene ratio increases from 1:1 to 3:1; from 5.7% (organic aerosol mass concentration, Δ&lt;i&gt;M&lt;/i&gt;&lt;sub&gt;o&lt;/sub&gt; = 4.2 μg/m&lt;sup&gt;3&lt;/sup&gt;) to 16.3% (Δ&lt;i&gt;M&lt;/i&gt;&lt;sub&gt;o&lt;/sub&gt; = 11.9 μg/m&lt;sup&gt;3&lt;/sup&gt;) when the reacted isoprene concentration is 25 ppb and from 3.1% (Δ&lt;i&gt;M&lt;/i&gt;&lt;sub&gt;o&lt;/sub&gt; = 1.2 μg/m&lt;sup&gt;3&lt;/sup&gt;) to 12.4% (Δ&lt;i&gt;M&lt;/i&gt;&lt;sub&gt;o&lt;/sub&gt; = 5.4 μg/m&lt;sup&gt;3&lt;/sup&gt;) when the reacted isoprene concentration is 15 ppb. The maximum SOA yield occurs when the N&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt;/isoprene ratio is greater than or equal to 3:1 as a combined result of multigeneration chemistry and peroxy radicals (RO&lt;sub&gt;2&lt;/sub&gt;) fate. We encourage future studies to consider both factors, which can vary under different laboratory and ambient conditions, when comparing SOA yields to better understand any differences observed. Our results highlight that multigeneration chemistry and the updated parameters including reaction rate constants and volatility distribution of products should be considered to enable a more comprehensive representation and prediction of SOA formation from NO","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 2","pages":"411–423 411–423"},"PeriodicalIF":2.9,"publicationDate":"2025-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsearthspacechem.4c00417","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444062","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":"The EDIBLES Survey IX: Simulations of the λ6614 DIB Profile Variations: A Surprising Connection with CH+","authors":"Charmi Bhatt*,&nbsp;Jan Cami,&nbsp;Peter J. Sarre,&nbsp;Harold Linnartz,&nbsp;Nick L. J. Cox,&nbsp;Amin Farhang,&nbsp;Jonathan Smoker,&nbsp;Heather MacIsaac,&nbsp;Haoyu Fan,&nbsp;Alexander Ebenbichler,&nbsp;Harshit Khandelwal,&nbsp;Alex Romanec,&nbsp;Meriem Elyajouri,&nbsp;Pascale Ehrenfreund,&nbsp;Bernard H. Foing,&nbsp;Ana Monreal-Ibero,&nbsp;Gabriel Missael Barco and Jacco Th. van Loon,&nbsp;","doi":"10.1021/acsearthspacechem.4c0023810.1021/acsearthspacechem.4c00238","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00238https://doi.org/10.1021/acsearthspacechem.4c00238","url":null,"abstract":"<p >The profiles of several diffuse interstellar bands (DIBs) show substructures that resemble unresolved rotational bands of the electronic transitions of large molecules. Their profiles show clear variations along the lines of sight, probing different physical conditions. Analysis of variations in such profiles can constrain the sizes and geometries of the DIB carriers and the physical conditions of the interstellar environments in which they reside. We investigate the properties of rotational band contours for perpendicular transitions in planar, oblate symmetric top molecules and compare such contours to the observed profile of the λ6614 DIB. We examine the shapes of the profiles as a function of the model parameters: the rotational constant <i>B</i> in the ground state, the relative change in the rotational constant of the excited state Δ<i>B</i>, the Coriolis coupling constant ζ, the rotational excitation temperature <i>T</i>_rot, and line width σ. We determine which parameters can reproduce the overall triple-peak profile of the λ6614 DIB and the variations across different lines of sight. We find that the substructures in the λ6614 DIB can be reproduced with an oblate top with rotational constant <i>B</i> = (2.2 ± 1.8) × 10^–3 cm^–1, Δ<i>B</i> = (−7.2 ± 0.4) × 10^–2%, and Coriolis coupling constant ζ = (2.9 ± 0.1) × 10^–1 cm^–1. Thus, if the λ6614 DIB carrier conforms to an oblate symmetric top geometry, it is most likely to be a ∼54C atom molecule. The profile variations correspond to changes in the rotational temperature from 81 to 92 K. We furthermore find that the intrinsic line width is a key parameter for each sightline and requires a range from 0.14 to 0.21 cm^–1 (or 2.8 to 4.2 km s^–1) across our sample to reproduce the observations. The intrinsic line width of the λ6614 DIB correlates with the width of the CH⁺ lines, suggesting an origin in the same environment. We conclude that the λ6614 DIB carrier resides in the same hot gas at low density that is probed by CH⁺.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 2","pages":"227–240 227–240"},"PeriodicalIF":2.9,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444061","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":"Exploring Forsterite Surface Catalysis in HCN Polymerization: Computational Insights for Astrobiology and Prebiotic Chemistry","authors":"Niccolò Bancone,&nbsp;Stefano Pantaleone,&nbsp;Piero Ugliengo,&nbsp;Albert Rimola* and Marta Corno*,&nbsp;","doi":"10.1021/acsearthspacechem.4c0028210.1021/acsearthspacechem.4c00282","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00282https://doi.org/10.1021/acsearthspacechem.4c00282","url":null,"abstract":"<p >Understanding the catalytic role of cosmic mineral surfaces is crucial for elucidating the chemical evolution needed for the emergence of life on Earth and other planetary systems. In this study, the catalytic role of silicate forsterite (Mg₂SiO₄) surfaces in the synthesis of iminoacetonitrile (IAN, HN=CH–CN) from the condensation of two hydrogen cyanide (HCN) molecules is investigated through quantum mechanical simulations. Using density functional theory calculations, the potential energy surfaces alongside the kinetics of various surface-mediated reactions leading to the formation of IAN are characterized. The effectiveness of forsterite as a catalyst is a delicate balance of the surface reactivity: on one side, the deprotonation of HCN is mandatory to trigger the dimerization; on the other side, the species should be weakly bound to the surface, thus allowing for their diffusion to meet with each other. The work reveals interesting counterintuitive results: the (120) and (101) forsterite surfaces (the less reactive ones) exhibit favorable catalytic properties for the reaction, in detriment to the (111) one (one of the most reactive). The implications of these findings in the astrobiology and prebiotic chemistry fields and for laboratory experiments are discussed, highlighting the potential role of cosmic silicates in the synthesis of complex organic molecules.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 2","pages":"303–313 303–313"},"PeriodicalIF":2.9,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsearthspacechem.4c00282","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444058","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}