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Pyrene-Based AIEE-Active Vertically Grown Luminescent Material for Selective and Sensitive Detection of TNT Vapor
IF 4.126 3区 化学 Q2 CHEMISTRY, PHYSICAL Pub Date : 2024-10-23 DOI: 10.1021/acs.jpcc.4c04823
Ram Prasad Bhatta, Ajeet Singh, Priya Bhandari, Tirupati Chander Sharma, Pramod Soni, Anindya Datta, Inamur Rahaman Laskar
Pyrene-based molecules often suffer from the “aggregation-caused quenching” (ACQ) effect because of their rigid planar structure having several π–π stacking interactions, which limit their applications as solid-state luminescent materials. From this perspective, it has been strategized to develop two compounds: 2-(pyren-1-yl)-4,6-bis(4-vinylphenyl)-1,3,5-triazine (VinTr) and 4-chloro-N,N-diphenyl-6-(pyren-1-yl)-1,3,5-triazin-2-amine (PyTrDA) in such a way that pyrene triazine frameworks are transformed into “aggregation-induced enhanced emission” (AIEE)-active molecules. All of the compounds showed positive responses to the quenching of trinitrotoluene (TNT). Within these compounds, PyTrDA showed excellent results on sensing TNT with a high level of sensitivity (limit of detection = 216 pM in solution and ∼7.0 ppb in the vapor phase) and selectivity, extending the results from the solution to the vapor phase. The quenching process is due to the photoinduced electron transfer (PET) from the probe (PyTrDA) to the analyte (TNT), which was confirmed by transient absorption spectroscopy. In addition to the relatively large quantum yield of PyTrDA, the morphology transformation from a planar sheet-type structure (observed in PyTr) to a vertically grown nanorod (in PyTrDA) offers increased surface area. The vertically grown nanostructural morphology of PyTrDA should properly facilitate the diffusion of TNT molecules and provide a confined environment, where one-to-one host–guest interactions between the probe molecule and analytes are possible. To the best of our knowledge, this is the first study that explores the role of nanostructural morphology with an enhanced surface area for improved TNT sensing using small organic molecules.
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引用次数: 0
Rethinking Porosity-Based Diffusivity Estimates for Sorptive Gas Transport at Variable Temperatures. 反思基于孔隙度的吸附性气体在变温条件下迁移的扩散率估算。
IF 10.8 1区 环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL Pub Date : 2024-10-22 Epub Date: 2024-10-04 DOI: 10.1021/acs.est.4c04048
Chelsea W Neil, Katherine C Swager, S Michelle Bourret, John P Ortiz, Philip H Stauffer

The detection of noble gas radioisotopes following a suspected underground nuclear explosion is the surest indicator that nuclear detonation has occurred. However, the accurate interpretation and attribution of radioisotopic signatures is only possible with a complete understanding of transport processes occurring between the nuclear cavity and surface. In the far-field, diffusive forces contributing to gas transport are impacted by temperature gradients and subsurface lithology. In the current study, we investigate diffusive transport of xenon (Xe), krypton (Kr), and sulfur hexafluoride (SF6) through intact Bandelier tuff at elevated temperatures using a newly developed high temperature diffusion cell. Diffusion coefficients determined using Finite Element Heat and Mass transfer code simulations and the Parameter ESTimation tool range from 2.6-3.1 × 10-6 m2/s at 20 °C, 3.4-5.1 × 10-6 m2/s at 40 °C, and 4.3-7.0 × 10-6 m2/s at 70 °C. Sorption was found to be an important transport mechanism at ambient temperatures (20 °C). Most critically, our study shows that empirical porosity-based diffusion estimates for these gases through tuff captured neither the magnitude nor trends relative to a nonsorbing sandstone. These new insights highlight the importance of experimental transport investigations and will be used to improve models for subsurface gas propagation relevant to proliferation detection and environmental contamination.

在疑似地下核爆炸后探测到惰性气体放射性同位素,是证明发生了核爆炸的最可靠指标。然而,只有全面了解核空腔和地表之间的迁移过程,才能准确解释和归因放射性同位素特征。在远场,气体迁移的扩散力受到温度梯度和地下岩性的影响。在当前的研究中,我们利用新开发的高温扩散单元,研究了氙(Xe)、氪(Kr)和六氟化硫(SF6)在高温条件下通过完整的班德尔凝灰岩的扩散输运。利用有限元传热传质代码模拟和参数ESTimation工具确定的扩散系数范围为:20 °C时 2.6-3.1 × 10-6 m2/s,40 °C时 3.4-5.1 × 10-6 m2/s,70 °C时 4.3-7.0 × 10-6 m2/s。研究发现,在环境温度(20 °C)下,吸附是一种重要的迁移机制。最重要的是,我们的研究表明,基于孔隙率的经验估计值既不能反映这些气体通过凝灰岩的扩散量,也不能反映相对于无吸附性砂岩的扩散趋势。这些新见解强调了实验性迁移研究的重要性,并将用于改进与扩散探测和环境污染有关的地下气体传播模型。
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引用次数: 0
Selective O2-to-H2O2 Electrosynthesis by a High-Performance, Single-Pass Electrofiltration System Using Ibuprofen-Laden CNT Membranes. 使用布洛芬负载型 CNT 膜的高性能单程电过滤系统实现 O2 到 H2O2 的选择性电合成。
IF 10.8 1区 环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL Pub Date : 2024-10-22 Epub Date: 2024-09-04 DOI: 10.1021/acs.est.4c06638
Qing Yang, Yuanzheng Zhang, Pengyu Xiao, Ruiping Liu, Huijuan Liu, Jiuhui Qu, Jae-Hong Kim, Meng Sun

Producing H2O2 through a selective, two-electron (2e) oxygen reduction reaction (ORR) is challenging, especially when it serves as an advanced oxidation process (AOP) for cost-effective water decontamination. Herein, we attain a 2e-selectivity H2O2 production using a carbon nanotube electrified membrane with ibuprofen (IBU) molecules laden (IBU@CNT-EM) in an ultrafast, single-pass electrofiltration process. The IBU@CNT-EM can generate H2O2 at a rate of 25.62 mol gCNT-1 h-1 L-1 in the permeate with a residence time of 1.81 s. We demonstrated that an interwoven, hydrophilic-hydrophobic membrane nanostructure offers an excellent air-to-water transport platform for ORR acceleration. The electron transfer number of the ORR for IBU@CNT at neutral pH was confirmed as 2.71, elucidating a near-2e selectivity to H2O2. Density functional theory (DFT) studies validated an exceptional charge distribution of the IBU@CNT for the O2 adsorption. The adsorption energies of the O2 and *OOH intermediates are proportional to the H2O2 selectivity (64.39%), higher than that of the CNT (37.81%). With the simple and durable production of H2O2 by IBU@CNT-EM electrofiltration, the permeate can actuate Fenton oxidation to efficiently decompose emerging pollutants and inactivate bacteria. Our study introduces a new paradigm for developing high-performance H2O2-production membranes for water treatment by reusing environmental functional materials.

通过选择性双电子(2e)氧还原反应(ORR)产生 H2O2 具有挑战性,尤其是当它作为一种高级氧化工艺(AOP)用于具有成本效益的水净化时。在此,我们利用碳纳米管电化膜(IBU)分子载体(IBU@CNT-EM)在超快、单程电过滤过程中实现了 2e 选择性 H2O2 生产。IBU@CNT-EM 在渗透液中生成 H2O2 的速率为 25.62 mol gCNT-1 h-1 L-1,停留时间为 1.81 秒。我们证明,亲水-疏水交织的纳米膜结构为 ORR 加速提供了一个极佳的空气-水传输平台。在中性 pH 值下,IBU@CNT 的 ORR 电子转移数被证实为 2.71,这说明它对 H2O2 的选择性接近 2e。密度泛函理论(DFT)研究验证了 IBU@CNT 在吸附 O2 时的特殊电荷分布。O2 和 *OOH 中间产物的吸附能与 H2O2 选择性(64.39%)成正比,高于 CNT 的选择性(37.81%)。通过 IBU@CNT-EM 电渗滤简单而持久地产生 H2O2,其渗透液可以促进芬顿氧化作用,从而有效地分解新出现的污染物并灭活细菌。我们的研究为通过重复利用环境功能材料开发用于水处理的高性能 H2O2 生产膜提出了一种新的范例。
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引用次数: 0
Regulation of Ocean Surface Currents and Seasonal Sea Ice Variations on the Occurrence and Transport of Organophosphate Esters in the Central Arctic Ocean. 海洋表层流和季节性海冰变化对北冰洋中部有机磷酸酯发生和迁移的调控。
IF 10.8 1区 环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL Pub Date : 2024-10-22 Epub Date: 2024-09-24 DOI: 10.1021/acs.est.4c05620
Jinghua Zhang, Yuxin Ma, Peigen Lin, Minghong Cai

Organophosphate esters (OPEs) have been observed in the remote Arctic Ocean, yet the influence of hydrodynamics and seasonal sea ice variations on the occurrence and transport of waterborne OPEs remains unclear. This study comprehensively examines OPEs in surface seawater of the central Arctic Ocean during the summer of 2020, integrating surface ocean current and sea ice concentration data. The results confirm significant spatiotemporal variations of the OPEs, with the total concentration of seven major OPEs averaging 780 ± 970 pg/L. Chlorinated OPEs, particularly tris(1-chloro-2-propyl) phosphate (TCPP), were dominant. The significant impact of hydrodynamics on the OPE transport is demonstrated by higher OPE concentrations in regions with strong surface currents, especially at the edge of the Beaufort Gyre and the confluence of the Beaufort Gyre and the Transpolar Drift. Furthermore, OPE levels were generally higher in drifting-ice-covered regions compared to ice-free regions, attributed to the volatilization of dissolved OPEs formerly trapped below the sea ice or newly released from melting snow and sea ice. Notably, TCPP decreased by only 19% in the ice-free area, while the more volatile triphenyl phosphate decreased by 63% compared with the partial ice region.

在遥远的北冰洋观测到了有机磷酸酯(OPEs),但流体力学和季节性海冰变化对水载 OPEs 发生和迁移的影响仍不清楚。本研究综合了表层洋流和海冰浓度数据,全面考察了 2020 年夏季北冰洋中部表层海水中的 OPE。研究结果证实,OPEs 存在明显的时空变化,七种主要 OPEs 的总浓度平均为 780 ± 970 pg/L。氯化 OPE,尤其是磷酸三(1-氯-2-丙基)酯(TCPP)占主导地位。流体动力学对 OPE 迁移的重大影响体现在表层洋流较强区域的 OPE 浓度较高,尤其是在波弗特环流边缘以及波弗特环流与跨极地漂流交汇处。此外,与无冰地区相比,漂流冰覆盖地区的 OPE 含量普遍较高,这是由于以前被困在海冰之下或新近从融雪和海冰中释放出来的溶解 OPE 的挥发所致。值得注意的是,在无冰区,三氯苯基磷酸酯仅减少了 19%,而挥发性更强的磷酸三苯酯则比部分冰区减少了 63%。
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引用次数: 0
Response of fs-Laser-Irradiated Diamond by Ultrafast Electron Diffraction 超快电子衍射对 fs 激光照射金刚石的响应
IF 4.126 3区 化学 Q2 CHEMISTRY, PHYSICAL Pub Date : 2024-10-22 DOI: 10.1021/acs.jpcc.4c05999
Franky Bernal, Erika J. Riffe, Shane W. Devlin, Sebastien Hamel, Rebecca K. Lindsey, Alexander H. Reid, Mianzhen Mo, Duan Luo, Patrick Kramer, Xiaozhe Shen, Athavan Nadarajah, Alastair Stacey, Steven Prawer, Heather D. Whitley, Craig P. Schwartz, Richard J. Saykally
Structural details of the proposed solid–liquid phase transition of carbon have remained elusive, despite years of study. While it is theorized that novel carbon materials form from a liquid precursor, experimental studies have lacked the temporal and spatial resolution necessary to fully characterize the purported liquid state. Here we utilize megaelectronvolt-ultrafast electron diffraction (MeV-UED) to study laser irradiated submicron diamond thin films in a pump–probe scheme with picosecond time resolution to visualize potential structural changes of excited diamond. We probe the structure of diamond using a combination of fluences (13, 40 J/cm2) and time delays (10, 25, 100 ps), but observe negligible changes in the static diffraction pattern of diamond and an overall decrease in diffraction intensity up to 100 ps after the excitation pulse. We thus conclude that no appreciable amount of liquid or graphitized carbon is present and highlight the structural resilience of bulk diamond to intense 800 nm ultrafast laser pulses.
尽管经过多年的研究,有关碳的固液相变的结构细节仍然难以捉摸。虽然理论上新型碳材料是由液态前体形成的,但实验研究却缺乏必要的时间和空间分辨率来全面描述所谓的液态。在这里,我们利用兆电子伏特-超快电子衍射(MeV-UED),以皮秒级的时间分辨率,通过泵浦探针方案研究激光辐照亚微米级金刚石薄膜,以观察激发金刚石的潜在结构变化。我们结合使用了通量(13、40 J/cm2)和时间延迟(10、25、100 ps)来探测金刚石的结构,但观察到金刚石静态衍射图样的变化可以忽略不计,并且在激发脉冲后 100 ps 内衍射强度总体下降。因此,我们得出结论:没有明显的液态碳或石墨化碳存在,并强调了大块金刚石在 800 纳米超快激光脉冲下的结构恢复能力。
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引用次数: 0
Light-Mediated Direct Decarboxylative Giese Aroylations without a Photocatalyst
IF 4.354 2区 化学 Q1 CHEMISTRY, ORGANIC Pub Date : 2024-10-22 DOI: 10.1021/acs.joc.4c02163
David M. Kitcatt, Eva Pogacar, Le Mi, Simon Nicolle, Ai-Lan Lee
Previous light-mediated approaches to the direct decarboxylative Giese aroylation reaction have mainly relied on the use of a photocatalyst and a reductive quenching pathway. By exploiting a mechanistically distinct oxidative protocol, we have successfully developed a photocatalyst-free, light-mediated direct Giese aroylation methodology.
{"title":"Light-Mediated Direct Decarboxylative Giese Aroylations without a Photocatalyst","authors":"David M. Kitcatt, Eva Pogacar, Le Mi, Simon Nicolle, Ai-Lan Lee","doi":"10.1021/acs.joc.4c02163","DOIUrl":"https://doi.org/10.1021/acs.joc.4c02163","url":null,"abstract":"Previous light-mediated approaches to the direct decarboxylative Giese aroylation reaction have mainly relied on the use of a photocatalyst and a reductive quenching pathway. By exploiting a mechanistically distinct oxidative protocol, we have successfully developed a photocatalyst-free, light-mediated direct Giese aroylation methodology.","PeriodicalId":57,"journal":{"name":"The Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":4.354,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142487151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Diversified Vegetation Cover Alleviates Microbial Resource Limitations within Soil Aggregates in Tailings. 多样化植被覆盖缓解了尾矿土壤骨料中微生物资源的限制。
IF 10.8 1区 环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL Pub Date : 2024-10-22 Epub Date: 2024-10-10 DOI: 10.1021/acs.est.4c06081
Wenliang Ju, Jordi Sardans, Haijian Bing, Jie Wang, Dengke Ma, Yongxing Cui, Chengjiao Duan, Xiankun Li, Qiaohui Fan, Josep Peñuelas, Linchuan Fang

Resource demand by soil microorganisms critically influences microbial metabolism and then influences ecosystem resilience and multifunctionality. The ecological remediation of abandoned tailings is a topic of broad interest, yet our understanding of microbial metabolic status in restored soils, particularly at the aggregate scale, remains limited. This study investigated microbial resources within soil aggregates from revegetated tailings and applied a vector model of ecoenzymatic stoichiometry to examine how different vegetation patterns (grassland, forest, or bare land control) impact microbial resource limitation. Five-year vegetation restoration significantly elevated carbon (C) and nitrogen (N) concentrations and their stoichiometric ratios in soil aggregates (approximately 2-fold), although these increases were not translated to in the microbial biomass and its stoichiometry. The activities of C- and phosphorus (P)-acquiring extracellular enzymes in these aggregates increased substantially postvegetation, with the most pronounced escalation in macroaggregates (>0.25 mm). The vector model results indicated soil microbial metabolism was colimited by C and P, most acutely in microaggregates (<0.25 mm). This colimitation was exacerbated by monotypic vegetation cover but mitigated under diversified vegetation cover. Soil nutrient stoichiometric ratios in vegetation restoration controlled microbial resource limitation, overshadowing the impact of heavy metals. Our findings underscore that optimizing resource allocation within soil aggregates through strategic revegetation can enhance microbial metabolism in tailings, which advocates for the implementation of diverse vegetation covers as a viable strategy to improve the ecological development of degraded landscapes.

土壤微生物的资源需求对微生物的新陈代谢有着至关重要的影响,进而影响生态系统的恢复能力和多功能性。废弃尾矿的生态修复是一个广受关注的话题,但我们对修复土壤中微生物代谢状况的了解仍然有限,尤其是在聚集体尺度上。本研究调查了植被恢复后尾矿土壤团聚体中的微生物资源,并应用生态酶化学计量学矢量模型研究了不同植被模式(草地、森林或裸地控制)对微生物资源限制的影响。为期五年的植被恢复大大提高了土壤团聚体中碳(C)和氮(N)的浓度及其化学计量比(约 2 倍),但这些增加并未转化为微生物生物量及其化学计量比的增加。植被覆盖后,这些团聚体中获取碳和磷的胞外酶的活性大幅提高,其中大团聚体(>0.25 毫米)的活性提高最为明显。矢量模型的结果表明,土壤微生物的新陈代谢受到碳和磷的限制,在微团聚体(>0.25 毫米)中最为明显。
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引用次数: 0
Electron–Nuclear Interactions of NV Defects in an Isotopically Purified 6H-28SiC Crystal
IF 4.126 3区 化学 Q2 CHEMISTRY, PHYSICAL Pub Date : 2024-10-22 DOI: 10.1021/acs.jpcc.4c05167
Larisa R. Latypova, Irina N. Gracheva, Darya V. Shurtakova, Fadis F. Murzakhanov, Margarita A. Sadovnikova, Georgy V. Mamin, Marat R. Gafurov
NV defects in silicon carbide (SiC) are emerging as a competitive alternative to NV centers in diamond due to advanced industrial-scale SiC production methods. We present a study of the ground-state electron–nuclear coupling of negatively charged nitrogen-vacancy NV centers in a 6H-SiC crystal by electron paramagnetic resonance and electron–nuclear double resonance techniques. The hyperfine and nuclear quadrupole interaction tensors have been precisely determined. The hyperfine coupling is found to be predominantly characterized by an isotropic contact Fermi part aiso = −1.125(2) MHz and a negligibly small dipole–dipole part b < 50 kHz. The nuclear quadrupole interaction is characterized by a coupling constant Cq = 2.530(3) MHz. The spin density distribution of the NVk2k1 center was calculated using density functional theory, and the theoretical electron–nuclear interaction values align well with experimental results. All established parameters are crucial for implementing NV defects in SiC for quantum magnetometry, other sensing applications, and as robust qubits.
{"title":"Electron–Nuclear Interactions of NV Defects in an Isotopically Purified 6H-28SiC Crystal","authors":"Larisa R. Latypova, Irina N. Gracheva, Darya V. Shurtakova, Fadis F. Murzakhanov, Margarita A. Sadovnikova, Georgy V. Mamin, Marat R. Gafurov","doi":"10.1021/acs.jpcc.4c05167","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c05167","url":null,"abstract":"NV<sup>–</sup> defects in silicon carbide (SiC) are emerging as a competitive alternative to NV<sup>–</sup> centers in diamond due to advanced industrial-scale SiC production methods. We present a study of the ground-state electron–nuclear coupling of negatively charged nitrogen-vacancy NV<sup>–</sup> centers in a 6<i>H</i>-SiC crystal by electron paramagnetic resonance and electron–nuclear double resonance techniques. The hyperfine and nuclear quadrupole interaction tensors have been precisely determined. The hyperfine coupling is found to be predominantly characterized by an isotropic contact Fermi part <i>a</i><sub><i>iso</i></sub> = −1.125(2) MHz and a negligibly small dipole–dipole part <i>b</i> &lt; 50 kHz. The nuclear quadrupole interaction is characterized by a coupling constant <i>C</i><sub>q</sub> = 2.530(3) MHz. The spin density distribution of the NV<sub><i>k</i>2<i>k</i>1</sub><sup>–</sup> center was calculated using density functional theory, and the theoretical electron–nuclear interaction values align well with experimental results. All established parameters are crucial for implementing NV<sup>–</sup> defects in SiC for quantum magnetometry, other sensing applications, and as robust qubits.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142486564","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}
引用次数: 0
Ozone Doping and Negative Temperature Response in the Explosion Limits of Ethylene-Oxygen Mixtures.
IF 2.7 2区 化学 Q3 CHEMISTRY, PHYSICAL Pub Date : 2024-10-22 DOI: 10.1021/acs.jpca.4c04778
Jianhang Li, Chenyu Li, Wenkai Liang, Wenhu Han, Chung K Law

In this work, effects of ozone (O3) addition on ethylene-oxygen (C2H4-O2) mixtures are computationally studied through the explosion limit profiles. The results show that the addition of minute quantities of ozone (with a mole fraction of 0.06% in the oxidizer) shifts the explosion limit of the C2H4-O3-O2 mixtures to the low-temperature regime. Further increases in the ozone concentration gradually strengthen the negative temperature coefficient (NTC) behavior at the second limit. That is because the explosion limit is primarily controlled by the ethylene ozonolysis reaction, and both the sensitivity analysis and chemical reaction rate perturbation method reveal specific kinetic reasons. Furthermore, it is shown that with the increasing equivalence ratio, the explosion limit curve with minute ozone addition rotates counterclockwise around a crossover point, while the explosion limit curve becomes complicated and the NTC behavior appears on the second limit with larger quantities of ozone addition. Furthermore, the effects of dilutions of nitrogen (N2), argon (Ar), carbon dioxide (CO2), and water (H2O) on the explosion limits are also studied. To elucidate the different wall elimination effects of different explosion limit regimes, the impacts of surface reactions of six radicals (H, O, OH, HO2, H2O2, and HCO) have been examined and the dominant radicals are found to be H and HO2. The H radicals significantly influence the first explosion limit, while the HO2 radicals impact the entire explosion limit.

{"title":"Ozone Doping and Negative Temperature Response in the Explosion Limits of Ethylene-Oxygen Mixtures.","authors":"Jianhang Li, Chenyu Li, Wenkai Liang, Wenhu Han, Chung K Law","doi":"10.1021/acs.jpca.4c04778","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c04778","url":null,"abstract":"<p><p>In this work, effects of ozone (O<sub>3</sub>) addition on ethylene-oxygen (C<sub>2</sub>H<sub>4</sub>-O<sub>2</sub>) mixtures are computationally studied through the explosion limit profiles. The results show that the addition of minute quantities of ozone (with a mole fraction of 0.06% in the oxidizer) shifts the explosion limit of the C<sub>2</sub>H<sub>4</sub>-O<sub>3</sub>-O<sub>2</sub> mixtures to the low-temperature regime. Further increases in the ozone concentration gradually strengthen the negative temperature coefficient (NTC) behavior at the second limit. That is because the explosion limit is primarily controlled by the ethylene ozonolysis reaction, and both the sensitivity analysis and chemical reaction rate perturbation method reveal specific kinetic reasons. Furthermore, it is shown that with the increasing equivalence ratio, the explosion limit curve with minute ozone addition rotates counterclockwise around a crossover point, while the explosion limit curve becomes complicated and the NTC behavior appears on the second limit with larger quantities of ozone addition. Furthermore, the effects of dilutions of nitrogen (N<sub>2</sub>), argon (Ar), carbon dioxide (CO<sub>2</sub>), and water (H<sub>2</sub>O) on the explosion limits are also studied. To elucidate the different wall elimination effects of different explosion limit regimes, the impacts of surface reactions of six radicals (H, O, OH, HO<sub>2</sub>, H<sub>2</sub>O<sub>2</sub>, and HCO) have been examined and the dominant radicals are found to be H and HO<sub>2</sub>. The H radicals significantly influence the first explosion limit, while the HO<sub>2</sub> radicals impact the entire explosion limit.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Rational Control of Maximum EMI/CPL Intensity and Wavelength of Bora[6]helicene via Polarity and Vibronic Effects. 通过极性和振动效应合理控制 Bora[6]helicene 的最大 EMI/CPL 强度和波长。
IF 4.8 2区 化学 Q2 CHEMISTRY, PHYSICAL Pub Date : 2024-10-22 DOI: 10.1021/acs.jpclett.4c02500
Yanli Liu, Qiushuang Xu, Li Wang, Aihua Gao, Quanjiang Li, Shenghui Chen, Yanliang Zhao, Meishan Wang, Jun Jiang, Chuanyi Jia

Solvent polarity control as an efficient methodology to regulate the chiroptical properties, including spectral shape, width, intensity, wavelength, etc., has emerged as a novel frontier in optical materials design. However, the underling relationship connecting polarity to the optical property remains unclear. Herein, using state-of-the-art computations and the FC|VG model, the solvent effect on the chiroptical properties of bora[6]helicene was accurately and systematically computed to shed light on this issue. It is found that the vibronic coupling is crucial in explaining the spectral shape, width, and relative intensity of different peaks. Moreover, the intensity and position of the emission (EMI) and circularly polarized luminescence (CPL) are closely related to the polarity of the solvent. Intriguingly, we got a series of good linear relationships between polarity and EMI|CPL (|r| ≥ 0.95). Thus, this parameter can be used as a potential descriptor to estimate the intensity and position of EMI|CPL, leading to new strategies for designing fully colored fluorescent materials.

{"title":"Rational Control of Maximum EMI/CPL Intensity and Wavelength of Bora[6]helicene via Polarity and Vibronic Effects.","authors":"Yanli Liu, Qiushuang Xu, Li Wang, Aihua Gao, Quanjiang Li, Shenghui Chen, Yanliang Zhao, Meishan Wang, Jun Jiang, Chuanyi Jia","doi":"10.1021/acs.jpclett.4c02500","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c02500","url":null,"abstract":"<p><p>Solvent polarity control as an efficient methodology to regulate the chiroptical properties, including spectral shape, width, intensity, wavelength, etc., has emerged as a novel frontier in optical materials design. However, the underling relationship connecting polarity to the optical property remains unclear. Herein, using state-of-the-art computations and the FC|VG model, the solvent effect on the chiroptical properties of bora[6]helicene was accurately and systematically computed to shed light on this issue. It is found that the vibronic coupling is crucial in explaining the spectral shape, width, and relative intensity of different peaks. Moreover, the intensity and position of the emission (EMI) and circularly polarized luminescence (CPL) are closely related to the polarity of the solvent. Intriguingly, we got a series of good linear relationships between polarity and EMI|CPL (|<i>r</i>| ≥ 0.95). Thus, this parameter can be used as a potential descriptor to estimate the intensity and position of EMI|CPL, leading to new strategies for designing fully colored fluorescent materials.</p>","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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