Carbenes are reactive species found across gas-phase environments, from combustion to planetary atmospheres and interstellar space. Their reactions with radicals represent a compelling path to increasing chemical complexity, in which the formation of the first aromatic ring is a foundational step. To date, no selective gas-phase bottom-up route to the smallest nitrogen-bearing aromatic ring, pyrrole, is known. We investigated the reaction of the simplest aminocarbene, aminomethylene, with the prototypical resonance stabilized propargyl radical. Photoelectron photoion coincidence spectroscopy and semiautomated electronic structure calculations reveal a barrierless, addition–elimination mechanism producing pyrrole + H. The reaction path depends on the orientation of propargyl during the association, in which the allenyl resonance form (H2C═C═CH•) of propargyl leads to pyrrole formation. This selective pathway highlights the promise of radical chemistry to fill important gaps in chemical reaction networks.
从燃烧到行星大气和星际空间，碳烯是在气相环境中发现的活性物质。它们与自由基的反应代表了增加化学复杂性的一个引人注目的途径，其中第一个芳香环的形成是一个基础步骤。迄今为止，没有选择性气相自下而上的路线，以最小的含氮芳香环，吡咯，是已知的。研究了最简单的氨基氨基乙烯与典型的共振稳定丙炔自由基的反应。光电子-光离子符合谱和半自动电子结构计算揭示了一种产生吡咯+ h的无障碍加成-消除机制。反应路径取决于丙炔在缔合过程中的取向，丙炔的烯基共振形式（H2C = C = CH•）导致了吡咯的形成。这种选择性途径突出了自由基化学填补化学反应网络重要空白的希望。
{"title":"Pyrrole without Life: Reaction of Aminomethylene with the Propargyl Radical","authors":"Rory McClish,Domenik Schleier,Jerry Kamer,Tina Kasper,Patrick Hemberger,Andras Bodi,Jordy Bouwman","doi":"10.1021/acs.jpclett.5c03948","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c03948","url":null,"abstract":"Carbenes are reactive species found across gas-phase environments, from combustion to planetary atmospheres and interstellar space. Their reactions with radicals represent a compelling path to increasing chemical complexity, in which the formation of the first aromatic ring is a foundational step. To date, no selective gas-phase bottom-up route to the smallest nitrogen-bearing aromatic ring, pyrrole, is known. We investigated the reaction of the simplest aminocarbene, aminomethylene, with the prototypical resonance stabilized propargyl radical. Photoelectron photoion coincidence spectroscopy and semiautomated electronic structure calculations reveal a barrierless, addition–elimination mechanism producing pyrrole + H. The reaction path depends on the orientation of propargyl during the association, in which the allenyl resonance form (H2C═C═CH•) of propargyl leads to pyrrole formation. This selective pathway highlights the promise of radical chemistry to fill important gaps in chemical reaction networks.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"41 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146111230","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}
Pub Date : 2026-02-04DOI: 10.1021/acs.jpclett.5c03267
Haoche Peng,Zackery Ferneyhough,Stefan Hilber,Arya Mojahed Naghi,Charles P. Shelor,Christoph Kreutz,Lu Wang,Pavel Matousek,Allison L. Stelling
Here we report the synthesis of two new 13C thymidine (T) isotopes labeled at two key positions in its structure, C2═O and C4═O, and the first IR spectra of each T isotope in H2O and in D2O. Our experimental isotope shifts and normal mode calculations indicate some structurally sensitive modes may be more localized than previously thought, making them regiosensitive probes of thymidine’s chemical environment. These results provide new physical insight into the normal modes of thymidine, and will guide future studies to determine how these structurally and environmentally sensitive probe vibrations are impacted by the duplex environment.
{"title":"Infrared Spectra of the Thymidine 13C2 and 13C4 Isotopes in H2O and D2O","authors":"Haoche Peng,Zackery Ferneyhough,Stefan Hilber,Arya Mojahed Naghi,Charles P. Shelor,Christoph Kreutz,Lu Wang,Pavel Matousek,Allison L. Stelling","doi":"10.1021/acs.jpclett.5c03267","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c03267","url":null,"abstract":"Here we report the synthesis of two new 13C thymidine (T) isotopes labeled at two key positions in its structure, C2═O and C4═O, and the first IR spectra of each T isotope in H2O and in D2O. Our experimental isotope shifts and normal mode calculations indicate some structurally sensitive modes may be more localized than previously thought, making them regiosensitive probes of thymidine’s chemical environment. These results provide new physical insight into the normal modes of thymidine, and will guide future studies to determine how these structurally and environmentally sensitive probe vibrations are impacted by the duplex environment.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"8 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146111065","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}
Electrochemical lithiation/delithiation of a nonstoichiometric silicon oxide (SiOx) thin-film electrode on a Li6.6La3Zr1.6Ta0.4O12 were analyzed using operando X-ray photoelectron spectroscopy (XPS). At the pristine SiOx surface, bulk Si and SiOx peaks were observed and remained unchanged in the capacity density from 0 to ∼1300 mAh gSi–1. At the capacity density of ∼1400 mAh gSi–1, however, new peaks corresponding to Li∼2.0Si and Li silicates appeared simultaneously with a substantial decrease in the bulk Si and SiOx peaks. These results imply that, in the initial stage, lithiation of SiOx occurred at the SiOx/Li6.6La3Zr1.6Ta0.4O12 interface to form LiySi and Li silicates, which was beyond the probing depth of XPS. Subsequently, lithiation gradually propagated into the bulk and approached the probing depth of XPS as the composition reached Li∼2.0Si, thereby elongating the ion conductive pathway. Thereafter, the position of the LiySi peak reversibly responded to the state of charge because lithiation/delithiation occurred uniformly across the SiOx thin film.
采用x射线光电子能谱（XPS）分析了非化学计量氧化硅（SiOx）薄膜电极在Li6.6La3Zr1.6Ta0.4O12上的电化学锂化/去锂化过程。在原始SiOx表面，观察到体积Si和SiOx峰，并且在容量密度从0到~ 1300 mAh gSi-1期间保持不变。然而，在容量密度为~ 1400 mAh gSi-1时，Li ~ 2.0Si和Li硅酸盐对应的新峰同时出现，而体积Si和SiOx峰大幅下降。这些结果表明，SiOx在初始阶段发生在SiOx/Li6.6La3Zr1.6Ta0.4O12界面，形成LiySi和Li硅酸盐，超出了XPS的探测深度。随后，锂化逐渐向体内扩散，并随着成分达到Li ~ 2.0Si而接近XPS的探测深度，从而延长了离子导电途径。此后，锂离子峰的位置可逆地响应电荷状态，因为锂化/去氧化在SiOx薄膜上均匀地发生。
{"title":"Electrochemical Lithiation and Delithiation of Amorphous Nonstoichiometric Silicon Oxide Thin-Film Electrode Studied by Operando X-ray Photoelectron Spectroscopy","authors":"Tsukasa Iwama,Ryosuke Sugimoto,Raimu Endo,Tsuyoshi Ohnishi,Masakazu Haruta,Takayuki Doi,Takuya Masuda","doi":"10.1021/acs.jpclett.5c04065","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c04065","url":null,"abstract":"Electrochemical lithiation/delithiation of a nonstoichiometric silicon oxide (SiOx) thin-film electrode on a Li6.6La3Zr1.6Ta0.4O12 were analyzed using operando X-ray photoelectron spectroscopy (XPS). At the pristine SiOx surface, bulk Si and SiOx peaks were observed and remained unchanged in the capacity density from 0 to ∼1300 mAh gSi–1. At the capacity density of ∼1400 mAh gSi–1, however, new peaks corresponding to Li∼2.0Si and Li silicates appeared simultaneously with a substantial decrease in the bulk Si and SiOx peaks. These results imply that, in the initial stage, lithiation of SiOx occurred at the SiOx/Li6.6La3Zr1.6Ta0.4O12 interface to form LiySi and Li silicates, which was beyond the probing depth of XPS. Subsequently, lithiation gradually propagated into the bulk and approached the probing depth of XPS as the composition reached Li∼2.0Si, thereby elongating the ion conductive pathway. Thereafter, the position of the LiySi peak reversibly responded to the state of charge because lithiation/delithiation occurred uniformly across the SiOx thin film.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"44 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146111062","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}
Pub Date : 2026-02-04DOI: 10.1021/acs.jpclett.5c03381
Ruomeng Li,Ya-Ke Li,Jianzhi Xu,Gao-Lei Hou
The development of new, efficient, and environmentally friendly ammonia synthesis catalysts is crucial, as the widely utilized Haber–Bosch process requires high temperature and high pressure for N2 dissociation, leading to significant energy consumption and carbon emissions. In this work, we systematically studied the catalytic ammonia synthesis from N2 and H2 over C60-supported RhnCo4–n (n = 0–4) clusters through density functional theory calculations. Our findings reveal that the reactions follow a distal association mechanism, with NH2* hydrogenation being identified as the highest energy barrier step and almost barrierless N2 dissociation. All four metal atoms are the active sites in NH3 synthesis. The C60-support effectively promotes nitrogen reduction and lowers the N–H formation barriers. The synergistic effect of Rhn, Co4–n, and the C60-support significantly improves the efficiency of the ammonia synthesis reaction. Higher Rh/Co ratios reduce the NH2* hydrogenation barrier. The C60Rh4 exhibits superior catalytic performance with the lowest NH2* hydrogenation barrier and highest turnover frequency (TOF) values; however, C60Co4 emerges as a more promising catalyst candidate for large-scale applications due to its low cost, unique ability to achieve thermal N2-to-NH3 conversion (unattainable by Rh-doped clusters), and TOF values exceeding all Rh-doped clusters except for Rh4. Our findings provide fundamental insights into catalytically active sites, optimal Rh/Co ratios, and C60’s synergistic role, guiding improved catalyst design for efficient NH3 synthesis.
{"title":"Catalytic Ammonia Synthesis from N2 and H2 over Fullerene-Supported RhnCo4–n (n = 0–4) Clusters: A Theoretical Study","authors":"Ruomeng Li,Ya-Ke Li,Jianzhi Xu,Gao-Lei Hou","doi":"10.1021/acs.jpclett.5c03381","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c03381","url":null,"abstract":"The development of new, efficient, and environmentally friendly ammonia synthesis catalysts is crucial, as the widely utilized Haber–Bosch process requires high temperature and high pressure for N2 dissociation, leading to significant energy consumption and carbon emissions. In this work, we systematically studied the catalytic ammonia synthesis from N2 and H2 over C60-supported RhnCo4–n (n = 0–4) clusters through density functional theory calculations. Our findings reveal that the reactions follow a distal association mechanism, with NH2* hydrogenation being identified as the highest energy barrier step and almost barrierless N2 dissociation. All four metal atoms are the active sites in NH3 synthesis. The C60-support effectively promotes nitrogen reduction and lowers the N–H formation barriers. The synergistic effect of Rhn, Co4–n, and the C60-support significantly improves the efficiency of the ammonia synthesis reaction. Higher Rh/Co ratios reduce the NH2* hydrogenation barrier. The C60Rh4 exhibits superior catalytic performance with the lowest NH2* hydrogenation barrier and highest turnover frequency (TOF) values; however, C60Co4 emerges as a more promising catalyst candidate for large-scale applications due to its low cost, unique ability to achieve thermal N2-to-NH3 conversion (unattainable by Rh-doped clusters), and TOF values exceeding all Rh-doped clusters except for Rh4. Our findings provide fundamental insights into catalytically active sites, optimal Rh/Co ratios, and C60’s synergistic role, guiding improved catalyst design for efficient NH3 synthesis.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"23 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146111064","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}
Ordered DNA condensates assembled with a block copolymer of PEG-poly(l-lysine) hierarchically fold the supercoiled plasmids into anisotropic “nanoworms” that maintain duplex continuity and display sequence-periodic, single-stranded hinges. After irreversible chemical cross-linking to preclude the potential DNA release, these architecturally preserved nanoscale condensates sustain sequence-specific transcription and coupled luciferase translation at efficiencies equaling or surpassing naked DNA, whereas jetPEI-derived disordered spheres remain transcriptionally silent. In both live cells and animals, eGFP-encoding nanoworm-like DNA condensates elicit robust cytosolic expression without requiring structural disassembly for liberation of the DNA payloads, thereby circumventing the obligatory “uncoat-and-release” step and eliminating the potential insertional-mutagenesis risk. These crystalline, nonviral DNA assemblies are postulated to offer a genome-integration-free platform for safer gene therapy.
{"title":"Release-Independent Transcription from Covalently Cross-Linked Hierarchically Folded DNA Condensates","authors":"Yue Wang,Xiyi Chen,Jinxuan He,Yan Zhao,Qixian Chen","doi":"10.1021/acs.jpclett.5c04105","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c04105","url":null,"abstract":"Ordered DNA condensates assembled with a block copolymer of PEG-poly(l-lysine) hierarchically fold the supercoiled plasmids into anisotropic “nanoworms” that maintain duplex continuity and display sequence-periodic, single-stranded hinges. After irreversible chemical cross-linking to preclude the potential DNA release, these architecturally preserved nanoscale condensates sustain sequence-specific transcription and coupled luciferase translation at efficiencies equaling or surpassing naked DNA, whereas jetPEI-derived disordered spheres remain transcriptionally silent. In both live cells and animals, eGFP-encoding nanoworm-like DNA condensates elicit robust cytosolic expression without requiring structural disassembly for liberation of the DNA payloads, thereby circumventing the obligatory “uncoat-and-release” step and eliminating the potential insertional-mutagenesis risk. These crystalline, nonviral DNA assemblies are postulated to offer a genome-integration-free platform for safer gene therapy.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"31 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146111097","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}
Two-dimensional (2D) antimony-based materials have garnered significant interest due to their intrinsic structural anisotropy, tunable electronic band structures, and superior carrier transport properties, rendering them highly promising for next-generation microelectronic and optoelectronic applications. Nevertheless, research on ternary antimony-based compounds remains at an early stage, despite their compositional versatility and potential for synergistically modulating electronic and optical properties through element-specific engineering. Here, we report a novel 2D ternary antimony chalcogenide oxide, Sb2S2O, which features a low-symmetry layered structure and pronounced in-plane anisotropy. The layered Sb2S2O crystals exhibit excellent broadband photoresponse performance across the 254-940 nm range, achieving a remarkable responsivity of 11.3 A W-1 and a specific detectivity of 6.5 × 1011 Jones. Moreover, the photodetectors demonstrate polarization-angle-dependent sensitivity spanning 266-808 nm, with the structural anisotropy of Sb2S2O giving rise to a maximum dichroic ratio of approximately 1.48 at 633 nm. Notably, modulation of the polarization angle enables dynamic control over the spatial distribution of photoexcited carriers and the interfacial potential landscape, thereby allowing efficient tuning of the device's optical response. This polarization-dependent tunability further allows the photodetector to operate in a dual-mode configuration for intelligent imaging, simultaneously achieving high-sensitivity detection and programmable contrast enhancement. The integration of deep learning algorithms with the multifunctional optoelectronic characteristics of Sb2S2O positions this material as a promising candidate for next-generation intelligent photodetection and adaptive vision technologies.
二维（2D）锑基材料由于其固有的结构各向异性、可调谐的电子能带结构和优越的载流子输运特性而获得了极大的兴趣，使其在下一代微电子和光电子应用中具有很高的前景。然而，对三元锑基化合物的研究仍处于早期阶段，尽管它们的成分多功能性和通过元素特定工程协同调制电子和光学性质的潜力。在这里，我们报道了一种新的二维三元硫系氧化锑Sb2S2O，它具有低对称层状结构和明显的面内各向异性。层状Sb2S2O晶体在254- 940nm范围内具有优异的宽带光响应性能，具有11.3 a W-1的响应率和6.5 × 1011 Jones的比探测率。此外，光电探测器在266-808 nm范围内表现出与偏振角相关的灵敏度，Sb2S2O的结构各向异性使其在633 nm处的最大二向色比约为1.48。值得注意的是，偏振角的调制可以动态控制光激发载流子的空间分布和界面电位，从而可以有效地调整器件的光响应。这种偏振相关的可调性进一步允许光电探测器在智能成像的双模式配置下工作，同时实现高灵敏度检测和可编程对比度增强。深度学习算法与Sb2S2O多功能光电特性的集成使该材料成为下一代智能光探测和自适应视觉技术的有前途的候选者。
{"title":"Polarization-Programmable 2D Sb<sub>2</sub>S<sub>2</sub>O Photodetectors for High-Precision Object Identification.","authors":"Shuo Liu, Yongsi Liu, Xinyun Zhou, Wanglong Wu, Bingkun Wang, Ruiying Ma, Le Yuan, Lingjie Zhao, Mianzeng Zhong","doi":"10.1021/acs.jpclett.5c04042","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c04042","url":null,"abstract":"<p><p>Two-dimensional (2D) antimony-based materials have garnered significant interest due to their intrinsic structural anisotropy, tunable electronic band structures, and superior carrier transport properties, rendering them highly promising for next-generation microelectronic and optoelectronic applications. Nevertheless, research on ternary antimony-based compounds remains at an early stage, despite their compositional versatility and potential for synergistically modulating electronic and optical properties through element-specific engineering. Here, we report a novel 2D ternary antimony chalcogenide oxide, Sb<sub>2</sub>S<sub>2</sub>O, which features a low-symmetry layered structure and pronounced in-plane anisotropy. The layered Sb<sub>2</sub>S<sub>2</sub>O crystals exhibit excellent broadband photoresponse performance across the 254-940 nm range, achieving a remarkable responsivity of 11.3 A W<sup>-1</sup> and a specific detectivity of 6.5 × 10<sup>11</sup> Jones. Moreover, the photodetectors demonstrate polarization-angle-dependent sensitivity spanning 266-808 nm, with the structural anisotropy of Sb<sub>2</sub>S<sub>2</sub>O giving rise to a maximum dichroic ratio of approximately 1.48 at 633 nm. Notably, modulation of the polarization angle enables dynamic control over the spatial distribution of photoexcited carriers and the interfacial potential landscape, thereby allowing efficient tuning of the device's optical response. This polarization-dependent tunability further allows the photodetector to operate in a dual-mode configuration for intelligent imaging, simultaneously achieving high-sensitivity detection and programmable contrast enhancement. The integration of deep learning algorithms with the multifunctional optoelectronic characteristics of Sb<sub>2</sub>S<sub>2</sub>O positions this material as a promising candidate for next-generation intelligent photodetection and adaptive vision technologies.</p>","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":" ","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146103167","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}
Pub Date : 2026-02-03DOI: 10.1021/acs.jpclett.5c03900
Mi Zhang,Andrew G. Seel,Patrick L. Cullen
Water-in-salt electrolytes have emerged as promising materials for energy storage devices, significantly extending the electrochemical stability window of water through confinement within a salt matrix. While the structure and distribution of water molecules in these systems is becoming increasingly better characterized, the molecular nature and energetics of water present a greater challenge. Measurement of the quantum kinetic energy of light atoms is a sensitive probe of their environment, reflecting the potential experienced by the atoms and inclusive of their zero-point energy. It is found that the mean kinetic energy of the proton and deuteron in the archetypal water-in-salt electrolyte system, LiTFSI-H2O, decreases as a function of salt concentration. This indicates that while the disruption of the hydrogen bond network of water is known to lead to an increasing OH stretching frequency, other components to the quantum kinetic energy must decrease to result in the overall lower measured average.
{"title":"Lowering of Proton and Deuteron Mean Kinetic Energy in the LiTFSI Water-in-Salt Electrolyte System","authors":"Mi Zhang,Andrew G. Seel,Patrick L. Cullen","doi":"10.1021/acs.jpclett.5c03900","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c03900","url":null,"abstract":"Water-in-salt electrolytes have emerged as promising materials for energy storage devices, significantly extending the electrochemical stability window of water through confinement within a salt matrix. While the structure and distribution of water molecules in these systems is becoming increasingly better characterized, the molecular nature and energetics of water present a greater challenge. Measurement of the quantum kinetic energy of light atoms is a sensitive probe of their environment, reflecting the potential experienced by the atoms and inclusive of their zero-point energy. It is found that the mean kinetic energy of the proton and deuteron in the archetypal water-in-salt electrolyte system, LiTFSI-H2O, decreases as a function of salt concentration. This indicates that while the disruption of the hydrogen bond network of water is known to lead to an increasing OH stretching frequency, other components to the quantum kinetic energy must decrease to result in the overall lower measured average.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"91 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146111127","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}
The binary 2-butynyl alcohol–H2O complex was explored using pulsed-jet Fourier transform microwave spectroscopy with complementary quantum chemical calculations. Distinct tunneling-induced splittings in the rotational spectra reveal two large-amplitude motions: internal rotation of water (V2 = 4.33 kJ mol–1) and concerted tunneling of water and the hydroxyl group (B2 = 6.61 kJ mol–1). The observed isomer is stabilized by dual OH···Ow and Ow–H···πC≡C hydrogen bonds. Electronic structure analyses indicate that methyl substitution strengthens the Ow–H···πC≡C interaction, oppositely modulating these two tunneling pathways─restricting water rotation while facilitating skeletal torsion. These findings demonstrate how substituent effects control tunneling cooperativity in hydrogen-bonded systems, offering mechanistic insight into substituent-controlled quantum hydrogen dynamics in weakly bound clusters.
{"title":"Substituent-Controlled Quantum Dynamics in 2-Butynyl Alcohol–Water Dimer: Insights from Rotational Spectroscopy","authors":"Yue Jiang,Mei Hong,Junhong Li,Junlin Lan,Jun Kang,Chenxu Wang,Junhua Chen,Hao Wang,Xingchen Liu,Xiaodong Wen,Jun Li,Qian Gou,Walther Caminati","doi":"10.1021/acs.jpclett.5c03881","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c03881","url":null,"abstract":"The binary 2-butynyl alcohol–H2O complex was explored using pulsed-jet Fourier transform microwave spectroscopy with complementary quantum chemical calculations. Distinct tunneling-induced splittings in the rotational spectra reveal two large-amplitude motions: internal rotation of water (V2 = 4.33 kJ mol–1) and concerted tunneling of water and the hydroxyl group (B2 = 6.61 kJ mol–1). The observed isomer is stabilized by dual OH···Ow and Ow–H···πC≡C hydrogen bonds. Electronic structure analyses indicate that methyl substitution strengthens the Ow–H···πC≡C interaction, oppositely modulating these two tunneling pathways─restricting water rotation while facilitating skeletal torsion. These findings demonstrate how substituent effects control tunneling cooperativity in hydrogen-bonded systems, offering mechanistic insight into substituent-controlled quantum hydrogen dynamics in weakly bound clusters.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"92 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098091","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}
Nitrogen-doped graphene single-atom catalysts (SACs) have shown remarkable promise in selective hydrogenation and hydrogen storage. However, the rationalization of hydrogen evolution in these systems is still challenging. In this paper, by systematically calculating hydrogen adsorption and dissociation energies on active 3-fold sites M-C3–xNx, with x ranging from 0 to 3 and with M = Co, Ni, Pd, we show that hydrogen dissociation is endothermic─except for Pd–N3 and Pd-CN2─and proceeds via two distinct mechanisms, depending on the nitrogen content of the site. For nitrogen-poor sites, dissociation follows a heterolytic pathway with a relatively high activation energy (0.6–1.1 eV), with a notable exception being the Pd–C2N site with a low barrier (0.37 eV). In contrast, nitrogen-rich sites favor homolytic dissociation, with a significantly lower activation barrier (below 0.4 eV). However, for Ni–N3, the electronic confinement of hydrogen imposed by nitrogen neighbors prevents true homolytic dissociation, with the two dissociated H atoms on the metal spontaneously recombining. Across all N-doped graphene SAC models considered, the calculated activation barriers exhibit a Brønsted–Evans–Polanyi scaling. This study provides a detailed understanding of hydrogen dissociation on graphene SACs, paving the way for the design of catalysts tailored to specific applications.
{"title":"How N-Doping Promotes Hydrogen Dissociation at Graphene-Based Single-Atom Catalysts","authors":"Safouan Ziat,Florian Brix,Arshak Tsaturyan,Bertrand Kierren,Émilie Gaudry","doi":"10.1021/acs.jpclett.5c03805","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c03805","url":null,"abstract":"Nitrogen-doped graphene single-atom catalysts (SACs) have shown remarkable promise in selective hydrogenation and hydrogen storage. However, the rationalization of hydrogen evolution in these systems is still challenging. In this paper, by systematically calculating hydrogen adsorption and dissociation energies on active 3-fold sites M-C3–xNx, with x ranging from 0 to 3 and with M = Co, Ni, Pd, we show that hydrogen dissociation is endothermic─except for Pd–N3 and Pd-CN2─and proceeds via two distinct mechanisms, depending on the nitrogen content of the site. For nitrogen-poor sites, dissociation follows a heterolytic pathway with a relatively high activation energy (0.6–1.1 eV), with a notable exception being the Pd–C2N site with a low barrier (0.37 eV). In contrast, nitrogen-rich sites favor homolytic dissociation, with a significantly lower activation barrier (below 0.4 eV). However, for Ni–N3, the electronic confinement of hydrogen imposed by nitrogen neighbors prevents true homolytic dissociation, with the two dissociated H atoms on the metal spontaneously recombining. Across all N-doped graphene SAC models considered, the calculated activation barriers exhibit a Brønsted–Evans–Polanyi scaling. This study provides a detailed understanding of hydrogen dissociation on graphene SACs, paving the way for the design of catalysts tailored to specific applications.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"37 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098092","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}
Gas-phase synthesized superatoms (SAs) consisting of a tungsten-atom-encapsulating silicon cage, W@Sin, were size-selectively deposited on substrates through soft landing, and their oxidative stability and electrical conductivity were evaluated. The size-dependent reactivity of W@Sin (n = 12–17) on C60 substrates toward O2 exposure was measured by X-ray photoelectron spectroscopy, while variable-temperature electrical measurements were conducted for the assembled films of W@Si15 and W@Si16. Both W@Si15 and W@Si16 on C60 exhibit enhanced oxidative resistance compared with neighboring sizes, and the assembled W@Si15 films show higher electrical conductivity than that of W@Si16. Theoretical calculations further indicate that W@Si15 retains a nearly spherical Si cage across charge states, whereas W@Si16 adopts a distorted structure with one protruding Si atom. This study reveals that SAs with high symmetric geometric structure are advantageous for achieving superior chemical stability and electrical conductivity in their assembled states.
{"title":"Competitive Stability of W@Si15 and W@Si16 Superatoms: Oxidative Reactivity and Electrical Conductivity","authors":"Takaho Yokoyama,Kanata Nakamura,Kazuya Terasaka,Takumi Ichikawa,Yugo Osada,Atsushi Nakajima","doi":"10.1021/acs.jpclett.5c04041","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c04041","url":null,"abstract":"Gas-phase synthesized superatoms (SAs) consisting of a tungsten-atom-encapsulating silicon cage, W@Sin, were size-selectively deposited on substrates through soft landing, and their oxidative stability and electrical conductivity were evaluated. The size-dependent reactivity of W@Sin (n = 12–17) on C60 substrates toward O2 exposure was measured by X-ray photoelectron spectroscopy, while variable-temperature electrical measurements were conducted for the assembled films of W@Si15 and W@Si16. Both W@Si15 and W@Si16 on C60 exhibit enhanced oxidative resistance compared with neighboring sizes, and the assembled W@Si15 films show higher electrical conductivity than that of W@Si16. Theoretical calculations further indicate that W@Si15 retains a nearly spherical Si cage across charge states, whereas W@Si16 adopts a distorted structure with one protruding Si atom. This study reveals that SAs with high symmetric geometric structure are advantageous for achieving superior chemical stability and electrical conductivity in their assembled states.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"82 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098088","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}
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