化学•材料最新文献

{"title":"Diverse Excitonic Phenomena in Asymmetric Trilayer Transition Metal Dichalcogenide Heterostructures","authors":"Zhe Zhang, Shudong Wang","doi":"10.1021/acs.jpclett.4c02526","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c02526","url":null,"abstract":"Interlayer excitons formed in two-dimensional transition metal dichalcogenide (TMD) heterostructures can be easily tuned due to the large spatial separation. In this work, we discuss the electronic and excitonic optical properties of trilayer heterostructures MoS₂/MoSSe/WSe₂ and MoS₂/MoSSe/MoSe₂ using state-of-the-art <i>GW</i>+BSE calculations. In both trilayer geometries, we discover a variety of exciton states, including interlayer excitons, every-other-layer excitons, and their hybridized states, <i>h</i>-IX. Importantly, the <i>h</i>-IXs are optically bright through hybridizing with the intralayer excitons, and the radiative lifetimes of <i>h</i>-IXs range from subnanoseconds to tens of microseconds at 77 K, depending on their compositions. We also reveal that the diversity of the low-lying IXs in MoS₂/MoSSe/MoSe₂ is higher than that of MoS₂/MoSSe/WSe₂, because more energy levels participate in transitions in MoS₂/MoSSe/MoSe₂. Our findings demonstrate that the appropriate energy alignment via manipulating the Janus layer is crucial for realizing rich excitonic states in trilayer TMD heterostructures.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":6.475,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142325792","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}

{"title":"Mechanistic Study on Oxygen Reduction Reaction in High-Concentrated Electrolytes for Aprotic Lithium–Oxygen Batteries","authors":"Yuwei Su, Zhiwei Zhao, Erkang Wang, Zhangquan Peng","doi":"10.1021/acs.jpclett.4c02455","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c02455","url":null,"abstract":"Highly concentrated electrolytes (HCEs) have energized the development of high-energy-density lithium metal batteries by facilitating the formation of robust inorganic-derived solid electrolyte interfaces on the lithium anode. However, the oxygen reduction reaction (ORR) occurring on the cathode side remains ambiguous in HCE-based lithium–oxygen (Li–O₂) batteries. Herein, we investigate the ORR mechanism in a highly concentrated LiTFSI-CH₃CN electrolyte using ultra-microelectrode voltammetry coupled with in situ spectroscopies. It is found that, compared to the dilute electrolyte, the HCE prolongs the lifespan of superoxide intermediates and decelerates their migration rate to the bulk solution, resulting in a change in growth mode for the discharge product of Li₂O₂ from traditional two-dimensional film growth to surface three-dimensional expansion growth. This alteration reduces the cathode passivation and thus delivers the enhanced discharge capacity. Additionally, the HCE also increases the reaction energy barrier between superoxide and solvent molecules, thereby minimizing parasitic reactions and improving the cycle performance of Li–O₂ batteries. Our study reveals the intricate interplay between electrolytes and oxygen intermediates and provides important insights into electrolyte chemistries for better Li–O₂ batteries.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":6.475,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142325794","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}

{"title":"An Approach for Highly Enantioselective Synthesis of meta-Disubstituted [n]Paracyclophanes","authors":"Jia Li, Ziyang Dong, Hongxuan Zhai, Jicheng Wu, Changgui Zhao","doi":"10.1021/acs.joc.4c02021","DOIUrl":"https://doi.org/10.1021/acs.joc.4c02021","url":null,"abstract":"Atroposelective synthesis of <i>meta</i>-disubstituted [<i>n</i>]paracyclophanes is a difficult task in organic chemistry. We describe a facile approach for the synthesis of <i>meta</i>-disubstituted [<i>n</i>]paracyclophanes using Pd-catalyzed enantioselective C–H olefination and sequential reductive cleavage. A wide range of [<i>n</i>]paracyclophanes was obtained with excellent enantioselectivity. Thermodynamic analysis revealed that the rotational barrier of <i>meta</i>-disubstituted [<i>n</i>]paracyclophanes was lower than that of <i>para</i>-disubstituted [<i>n</i>]paracyclophanes. The synthesized planar-chiral [14]paracyclophane showed a bright fluorescence emission and impressive circularly polarized luminescence activity.","PeriodicalId":57,"journal":{"name":"The Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":4.354,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142325835","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}

{"title":"Modular Synthesis of Azidobicyclo[2.1.1]hexanes via (3 + 2) Annulation of α-Substituted Vinyl Azides and Bicyclo[1.1.0]butanes","authors":"Sai Hu, Yuhong Gao, Yuming Pan, Dongshun Ni, Li Deng","doi":"10.1021/acs.joc.4c01920","DOIUrl":"https://doi.org/10.1021/acs.joc.4c01920","url":null,"abstract":"Here, we present a mild and rapid method to access azidobicyclo[2.1.1]hexanes via formal (3 + 2) cycloaddition of α-substituted vinyl azides and bicyclo[1.1.0]butanes under Lewis acid catalysis. A wide range of α-substituted vinyl azides were tolerated under mild conditions. Notably, the resulting cycloadducts could be transformed into structurally attractive 3-azabicyclo[3.1.1]heptenes through microwave-promoted rearrangement. The utilities were highlighted by copper(I)-catalyzed Huisgen 1,3-dipolar cycloaddition of tertiary alkyl azide and further transformation of the azide and ketone groups.","PeriodicalId":57,"journal":{"name":"The Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":4.354,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142325834","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}

{"title":"Crystals of Organic Acid–Base Complexes Defy the ΔpKa Rule Under Compression","authors":"Shovan Das, Saied Md Pratik, Ayan Datta","doi":"10.1021/acs.jpcc.4c05301","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c05301","url":null,"abstract":"Crystals of organic acid–base adducts are major components in active pharmaceutical ingredients. These 1:1 adducts either form a cocrystal with a hydrogen-bonded motif or a salt by transfer of a proton from the acid to the base. As a <i>rule of thumb</i>, if the difference in p<i>K</i>_<i>a</i> between the protonated base and the acid (Δp<i>K</i>_<i>a</i>) is &lt; −1, a cocrystal is expected, while Δp<i>K</i>_<i>a</i> &gt; 4 leads to a salt, and in the intermediate zone (−1 ≤ Δp<i>K</i>_<i>a</i> ≤ 4) both cocrystal and salt are observed. The preferred crystalline form for 1:1 adducts of pyridine, pyridazine, pyrazine, and furan with formic acid is elucidated using genetic algorithm-assisted <i>first-principles</i> crystal structure predictions. In agreement with the Δp<i>K</i>_<i>a</i> rule, all the adducts stabilize as H-bonded cocrystals under ambient pressure. However, under isotropic pressure, formic acid transfers the protons to the three nitrogenous bases, forming salts of pyridinium formate, pyridazinium formate, and pyrazinium formate. External pressure is found to dictate the cocrystal–salt equilibrium. Critical pressure (<i>P</i>_<i>c</i>) required to induce cocrystal → salt conversion for formic acid··· pyridine/pyridazine/pyrazine is 3, 5, and 15 GPa, respectively. Compression is shown to enhance the electrostatic interactions between the molecules, leading to additional stabilization of the ionic configurations, namely, N⁺-H···O^– in salts vis-à-vis the neutral N–H···O motifs in the cocrystals. Violating the Δp<i>K</i>_<i>a</i> rule, <i>P</i>_<i>c</i> overcomes the free energy required for the proton transfer (Δ<i>G</i>_PT) to stabilize the salts. The very high Δ<i>G</i>_PT = 177.9 kcal/mol for the furan···formic acid adduct prevents salt formation even at 30 GPa. Apart from thermodynamic and kinetic control during crystallization, <i>pressure</i> acts as a key control for organic acid–base adducts.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142325799","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":"Resolving Atmospheric Oxygenated Organic Molecules in Urban Beijing Using Online Ultrahigh-Resolution Chemical Ionization Mass Spectrometry","authors":"Yi Yuan, Xin Chen, Runlong Cai, Xiaoxiao Li, Yuyang Li, Rujing Yin, Dandan Li, Chao Yan, Yongchun Liu, Kebin He, Markku Kulmala, Jingkun Jiang","doi":"10.1021/acs.est.4c04214","DOIUrl":"https://doi.org/10.1021/acs.est.4c04214","url":null,"abstract":"Gaseous oxygenated organic molecules (OOMs) are crucial precursors of atmospheric organic aerosols. OOMs in urban atmospheres have complex compositions, posing challenges to understanding their formation, evolution, and influences. In this study, we identify 2403 atmospheric gaseous OOMs in urban Beijing using online nitrate-based chemical ionization Orbitrap mass spectrometry based on one-year atmospheric measurements. We find that OOMs in urban atmospheres can be identified with higher accuracy and wider coverage, compared to previously used online mass spectrometry. With optimized OOM resolving capabilities, previous knowledge of OOMs in urban atmospheres can be expanded. First, clear homologous and oxygen-addition characteristics of the OOMs are revealed. Second, OOMs with lower concentrations or higher masses are identified and characterized with high confidence, e.g., OOMs with masses above 350 Da. In particular, dimers of OOMs (e.g., C₂₀H₃₂O_8–15N₂), crucial species for organic nucleation, are identified. During four seasons, nitrogen-containing OOMs dominate the total concentration of OOMs, and OOMs are mainly from aromatic and aliphatic oxidation. Additionally, radicals with similar composition as OOMs, intermediates for OOM formation, are identified with clear diurnal variation, e.g., C_<i>n</i>H_{2<i>n</i>–5}O₆ radicals (<i>n</i> = 8–10) and C_<i>m</i>H_{2<i>m</i>–4}NO₉ radicals (<i>m</i> = 9–10), peak during the daytime and nighttime, respectively, previously having scarce measurement evidence in urban atmospheres.","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":9.028,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142325693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Uniaxial Tensile-Induced Phase Transition in Graphynes","authors":"K. Jacques Kotoko, Komi Sodoga, Yusuf Shaidu, Nicola Seriani, Sangkha Borah, Katawoura Beltako","doi":"10.1021/acs.jpcc.4c01233","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c01233","url":null,"abstract":"The field of materials science has a strong focus on the study of two-dimensional (2D) materials, with particular emphasis on graphene (GR) and its various allotropes such as graphynes (GYs). In this work, we explored through molecular dynamics simulations at finite temperatures the effects of uniaxial loading on GY structures, which led to new phases that arise at specific temperatures. We identified three new phases in α- and [14, 14, 18]-GYs, which we named C₁₆-GY, C₁₄-GY, and C₁₂-GR. These phases have the remarkable property of remaining stable in a wide range of temperatures (<i>T</i> ≤ 4 and 300 K ≤ <i>T</i> ≤ 600 K). Moreover, we have conducted extensive investigations into the mechanical properties of these newly discovered phases. Through molecular dynamics simulations at finite temperatures, using empirical potential, we have gained valuable insights into how these materials behave under different temperature conditions. Our results reveal that at room temperature (300 K), C₁₆-, C₁₄-GYs exhibit high Young moduli in the <b>x</b>-direction (58.85 and 65.88 N/m) compared to α- and [14, 14, 18]-GYs (46.63 and 43.98 N/m), respectively. Additionally, these new phases exhibit mechanical properties that exceed those of phosphorene, germanene, silicene, and stanene. Importantly, both their mechanical and dynamic stability have been positively confirmed. As a result, these materials are promising candidates for various mechanical applications.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142325793","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":"Synthesis and Understanding of the Role of Donor-Tetracyanobutadiene in Porphyrin β-Periphery toward Ultrafast Charge Transfer Dynamics","authors":"Andrew W. Dawson, Bijesh Sekaran, Somnath Das, Rajneesh Misra, Francis D’Souza","doi":"10.1021/acs.jpcc.4c05066","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c05066","url":null,"abstract":"The porphyrins, structurally analogous to chlorophyll pigment, have drawn significant interest in mimicking natural photosynthetic processes in energy conversion applications. In this work, a new set of β-substituted free-base (H₂P) and zinc-porphyrins (ZnP) have been designed (<b>5</b>–<b>19</b>) and synthesized employing ferrocene (Fc), triphenylamine (TPA), and carbazole (Cz) as secondary donors (D) and further incorporated tetracyanobuta-1,3-diene (TCBD) as strong electron acceptor (A) entity following Sonogashira cross-coupling and subsequent [2 + 2] cycloaddition–retroelectrocyclization reactions. Steady-state optical data exhibit a broad absorption in the 650–800 nm region, particularly in <b>15</b>–<b>19</b>, corroborating ground-state charge polarization leading to intramolecular charge transfer (CT) in these systems. Strong fluorescence quenching in all of the systems (<b>5</b>–<b>19</b>) compared to the control compounds (<b>C1</b> and <b>C2</b>) further suggests excited-state nonradiative photoprocesses predominate in these β-substituted dyads and triads, particularly after TCBD incorporations (<b>15</b>–<b>19</b>). Though the secondary donors quickly oxidize in <b>5</b>–<b>10</b>, the same becomes difficult in <b>15</b>–<b>19</b>, indicating an electronic influence of TCBD, leading to the respective formation of MP^•–-D^•+ and MP^•+-A^•–-D (MP = 2H or Zn) charge-separated (CS) species in a polar environment, which the molecular orbital positioning of the CT entities from computational studies has also justified. Finally, spectral and temporal dynamics of different photoproducts in these compounds have been assessed from femtosecond transient absorption studies, and subsequent fitting of the transient data identifies Cz contributing to the most stable and thus long-lived CS states, brightening their outstanding promise in solar energy harvesting and related electronic applications.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142325819","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":"Correction to “Role of H2O Adsorption in CO Oxidation over Cerium-Oxide Cluster Anions (CeO2)nO– (n = 1–4)”","authors":"Jiao-Jiao Chen, Si-Dun Wang, Xun-Lei Ding, Sheng-Gui He","doi":"10.1021/acs.jpclett.4c02726","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c02726","url":null,"abstract":"In Figure 4, the plot should be replaced, as shown below:<img alt=\"\" src=\"/cms/10.1021/acs.jpclett.4c02726/asset/images/medium/jz4c02726_0001.gif\"/> In the picture, the solid lines represent the LUMO energies of (CeO₂)_<i>n</i>O^– and (CeO₂)_<i>n</i>OH₂O^– clusters. However, the energies of these clusters were confused, leading to incorrect line positions that are inconsistent with the statement “while the LUMO energy of Ce₃O₇H₂O^– (−1.29 eV) is slightly higher than that of Ce₃O₇^– (−1.37 eV)”. This article has not yet been cited by other publications.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":6.475,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142325797","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}

{"title":"Scanning Tunneling Microscopy of Bimetallic Ni/Co-HITP Metal–Organic Framework Monolayers","authors":"Fubiao Gu, Sisheng Shu, Christopher E. Patrick, Martin R. Castell","doi":"10.1021/acs.jpcc.4c06050","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c06050","url":null,"abstract":"Metals (Ni, Co) and hexaaminotriphenylene (HATP) molecules are evaporated separately in an ultrahigh vacuum onto the Au(111) surface. During an annealing step, monolayer single metal and bimetallic Ni_<i>x</i>Co_3–<i>x</i>(HITP)₂ metal–organic frameworks (MOFs) are formed via an on-surface reaction of the organic molecules with the metals. The MOFs are characterized by scanning tunneling microscopy (STM), which reveals the hexagonal framework structures and growth processes. The pure Ni₃(HITP)₂ and bimetallic Ni_<i>x</i>Co_3–<i>x</i>(HITP)₂ frameworks have a similar isotropic island morphology, while the Co₃(HITP)₂ islands are ribbon shaped. Individual Ni and Co metal centers can be atomically identified by their different apparent heights in the STM images of the bimetallic framework. Density functional theory (DFT) calculations indicate that the apparent height difference is caused by electronic effects rather than the difference of topography. The STM images further reveal that in the mixed-metal MOFs the Ni and Co centers are distributed randomly.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142329094","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}