Pub Date : 2025-04-05DOI: 10.1021/acs.jpclett.5c00210
Ravi Malik, Nore Stolte, Harald Forbert, Amalendu Chandra, Dominik Marx
Isotopic substitution of light hydrogen atoms with heavier deuterium atoms in liquid water renders the resulting liquid, heavy water (D2O), poisonous to most organisms when it replaces a critical fraction of water in living organisms. The mechanisms through which heavy water disrupts biological function are challenging to disentangle experimentally. Isotopic substitution has long been known to affect the H-bond dynamics of liquid water, but experiments have yet to quantify the extent of the differences in the time scales of H-bond breaking and making processes between H2O and D2O. In this work, we analyze H-bond dynamics through extensive coupled cluster-quality path integral simulations of H2O and D2O under ambient conditions that grant access to unambiguous molecular analyses. We find substantial isotope substitution effects on the rates of H-bond formation and breaking, and H-bond lifetimes, with dynamics in D2O ∼25% slower than in H2O. The toxicity of D2O can thus be ascribed, at least in part, to the effect of slowed H-bond dynamics on biochemical reactions.
{"title":"Accurate Determination of Isotope Effects on the Dynamics of H-Bond Breaking and Making in Liquid Water","authors":"Ravi Malik, Nore Stolte, Harald Forbert, Amalendu Chandra, Dominik Marx","doi":"10.1021/acs.jpclett.5c00210","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c00210","url":null,"abstract":"Isotopic substitution of light hydrogen atoms with heavier deuterium atoms in liquid water renders the resulting liquid, heavy water (D<sub>2</sub>O), poisonous to most organisms when it replaces a critical fraction of water in living organisms. The mechanisms through which heavy water disrupts biological function are challenging to disentangle experimentally. Isotopic substitution has long been known to affect the H-bond dynamics of liquid water, but experiments have yet to quantify the extent of the differences in the time scales of H-bond breaking and making processes between H<sub>2</sub>O and D<sub>2</sub>O. In this work, we analyze H-bond dynamics through extensive coupled cluster-quality path integral simulations of H<sub>2</sub>O and D<sub>2</sub>O under ambient conditions that grant access to unambiguous molecular analyses. We find substantial isotope substitution effects on the rates of H-bond formation and breaking, and H-bond lifetimes, with dynamics in D<sub>2</sub>O ∼25% slower than in H<sub>2</sub>O. The toxicity of D<sub>2</sub>O can thus be ascribed, at least in part, to the effect of slowed H-bond dynamics on biochemical reactions.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"34 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143782884","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 : 2025-04-04DOI: 10.1021/acs.jpclett.5c00436
Tingni Wu, Kai Yin, Yuchun He, Lingxiao Wang, Haonan Yu, Yin Huang, Ji-An Duan, Christopher J. Arnusch
Thermal radiation management is an important aspect of thermal engineering and plays a crucial role in various industrial and environmental applications. However, either cooling or heating devices alone can exacerbate all-season consumption during hot summers or cold winters. We have designed a dual-mode thermal management device that can switch modes by a pull-out method, with femtosecond laser-induced graphene (LIG) on the surface of a polyimide membrane as the heating surface and a SiO2 hollow microsphere coating as the cooling surface. Due to the multi-interface reflection between SiO2 hollow microspheres and air, high reflectivity (93%) and 97% thermal infrared emissivity can be obtained. Under a solar irradiation intensity of 75 J/cm2, a temperature decrease of 6.3 °C can be realized. On the other hand, LIG can achieve an ultra-ambient temperature increase of 35 °C due to its excellent solar light absorption characteristics (ε ≈ 97%) and high thermal conductivity. Temperature regulation can be achieved by switching heating and cooling modes, which shows great promise in agriculture and for food and goods preservation. Also, this design is expected to offer a new approach to energy efficient cooling and heating in architecture.
{"title":"All-Season Passive Thermal Management Film with Multifunctionality for Efficient Radiative Cooling and Solar Heating","authors":"Tingni Wu, Kai Yin, Yuchun He, Lingxiao Wang, Haonan Yu, Yin Huang, Ji-An Duan, Christopher J. Arnusch","doi":"10.1021/acs.jpclett.5c00436","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c00436","url":null,"abstract":"Thermal radiation management is an important aspect of thermal engineering and plays a crucial role in various industrial and environmental applications. However, either cooling or heating devices alone can exacerbate all-season consumption during hot summers or cold winters. We have designed a dual-mode thermal management device that can switch modes by a pull-out method, with femtosecond laser-induced graphene (LIG) on the surface of a polyimide membrane as the heating surface and a SiO<sub>2</sub> hollow microsphere coating as the cooling surface. Due to the multi-interface reflection between SiO<sub>2</sub> hollow microspheres and air, high reflectivity (93%) and 97% thermal infrared emissivity can be obtained. Under a solar irradiation intensity of 75 J/cm<sup>2</sup>, a temperature decrease of 6.3 °C can be realized. On the other hand, LIG can achieve an ultra-ambient temperature increase of 35 °C due to its excellent solar light absorption characteristics (ε ≈ 97%) and high thermal conductivity. Temperature regulation can be achieved by switching heating and cooling modes, which shows great promise in agriculture and for food and goods preservation. Also, this design is expected to offer a new approach to energy efficient cooling and heating in architecture.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"18 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143775884","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 : 2025-04-04DOI: 10.1021/acs.jpclett.5c00323
Lyra J. Sauer, H. Floyd Davis
The photodissociation of gaseous pyruvic acid at three representative wavelengths, 369.74, 354.45, and 322.50 nm, was studied under collision-free molecular beam conditions. Kinetic energy distributions of the neutral products were measured using tunable vacuum ultraviolet photoionization followed by mass spectrometric analysis. Decarboxylation (CO2 elimination) was dominant for all three wavelengths, producing primarily ground state singlet methylhydroxycarbene, 1CH3COH, as well as a minor yield of electronically excited 3CH3COH. Excitation at 369.74 and 354.45 nm produced 1CH3COH with internal energies lying below and above the calculated potential energy barriers for isomerization to vinyl alcohol (C2H3OH) and acetaldehyde (CH3CHO). This suggests that the bimolecular chemistry of CH3COH may be important in the atmosphere. At 322.5 nm, C–C bond fission producing HOCO + CH3CO was also observed as a minor channel. While decarboxylation producing 1CH3COH + CO2 on the singlet potential energy surface (PES) is clearly dominant, observation of 3CH3COH + CO2 and HOCO + CH3CO confirms that the triplet PES also plays a role in pyruvic acid photochemistry in the actinic region.
{"title":"Unraveling the Primary Photochemistry of Pyruvic Acid: Direct Observation of Three Competing Channels","authors":"Lyra J. Sauer, H. Floyd Davis","doi":"10.1021/acs.jpclett.5c00323","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c00323","url":null,"abstract":"The photodissociation of gaseous pyruvic acid at three representative wavelengths, 369.74, 354.45, and 322.50 nm, was studied under collision-free molecular beam conditions. Kinetic energy distributions of the neutral products were measured using tunable vacuum ultraviolet photoionization followed by mass spectrometric analysis. Decarboxylation (CO<sub>2</sub> elimination) was dominant for all three wavelengths, producing primarily ground state singlet methylhydroxycarbene, <sup>1</sup>CH<sub>3</sub>COH, as well as a minor yield of electronically excited <sup>3</sup>CH<sub>3</sub>COH. Excitation at 369.74 and 354.45 nm produced <sup>1</sup>CH<sub>3</sub>COH with internal energies lying below and above the calculated potential energy barriers for isomerization to vinyl alcohol (C<sub>2</sub>H<sub>3</sub>OH) and acetaldehyde (CH<sub>3</sub>CHO). This suggests that the bimolecular chemistry of CH<sub>3</sub>COH may be important in the atmosphere. At 322.5 nm, C–C bond fission producing HOCO + CH<sub>3</sub>CO was also observed as a minor channel. While decarboxylation producing <sup>1</sup>CH<sub>3</sub>COH + CO<sub>2</sub> on the singlet potential energy surface (PES) is clearly dominant, observation of <sup>3</sup>CH<sub>3</sub>COH + CO<sub>2</sub> and HOCO + CH<sub>3</sub>CO confirms that the triplet PES also plays a role in pyruvic acid photochemistry in the actinic region.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"108 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143782885","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 : 2025-04-04DOI: 10.1021/acs.jpclett.5c00478
Jindong Bai, Yuedong Wang, Baopeng Yang, Zhiyi Liu, Xiao Guo, Tao Xu, Fangyan Ang, Haipeng Xie, Fangping Ouyang, Jin Li, Han Huang
Aluminum molybdate (Al2Mo3O12) exhibits superior properties for wide bandgap, chemical flexibility, negative thermal expansion, and good thermal stability. However, Al2Mo3O12 prepared by traditional processes still suffered from inefficiency and poor quality so far. Here, we report on epitaxial growth of α-Al2Mo3O12 nanoflake arrays with unidirectional domain orientations on c-sapphire via chemical vapor deposition. Optical microscopy, atomic force microscopy, scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, high-resolution transmission electron microscopy, selected area electron diffraction, and Raman spectroscopy measurements reveal the high-quality of as-grown samples and the specific epitaxial relationship between α-Al2Mo3O12 and c-sapphire: α-Al2Mo3O12[021] || sapphire[112̅0] and α-Al2Mo3O12[02̅1] || sapphire[11̅00]. Phonon polarizations of α-Al2Mo3O12 exhibit a strong anisotropy ratio up to 3.13 for Ag modes, which can be used to identify the crystal orientation. The abnormal temperature dependence of MoO4 symmetric stretching vibration phonon modes (SSVPMs) reveal giant anharmonic phonon–phonon interaction in α-Al2Mo3O12. The ultralow thermal conductivity of α-Al2Mo3O12 is predicted by the ultrashort phonon lifetime of ∼0.12 ps. Our findings provide insight into the thermal properties of α-Al2Mo3O12 and are helpful for the application in polarization-sensitive optoelectronic detector and thermoelectric material.
{"title":"Phonon Anisotropy and Anharmonicity in Epitaxial Al2Mo3O12 Nanoflakes","authors":"Jindong Bai, Yuedong Wang, Baopeng Yang, Zhiyi Liu, Xiao Guo, Tao Xu, Fangyan Ang, Haipeng Xie, Fangping Ouyang, Jin Li, Han Huang","doi":"10.1021/acs.jpclett.5c00478","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c00478","url":null,"abstract":"Aluminum molybdate (Al<sub>2</sub>Mo<sub>3</sub>O<sub>12</sub>) exhibits superior properties for wide bandgap, chemical flexibility, negative thermal expansion, and good thermal stability. However, Al<sub>2</sub>Mo<sub>3</sub>O<sub>12</sub> prepared by traditional processes still suffered from inefficiency and poor quality so far. Here, we report on epitaxial growth of α-Al<sub>2</sub>Mo<sub>3</sub>O<sub>12</sub> nanoflake arrays with unidirectional domain orientations on c-sapphire via chemical vapor deposition. Optical microscopy, atomic force microscopy, scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, high-resolution transmission electron microscopy, selected area electron diffraction, and Raman spectroscopy measurements reveal the high-quality of as-grown samples and the specific epitaxial relationship between α-Al<sub>2</sub>Mo<sub>3</sub>O<sub>12</sub> and c-sapphire: α-Al<sub>2</sub>Mo<sub>3</sub>O<sub>12</sub>[021] || sapphire[112̅0] and α-Al<sub>2</sub>Mo<sub>3</sub>O<sub>12</sub>[02̅1] || sapphire[11̅00]. Phonon polarizations of α-Al<sub>2</sub>Mo<sub>3</sub>O<sub>12</sub> exhibit a strong anisotropy ratio up to 3.13 for A<sub>g</sub> modes, which can be used to identify the crystal orientation. The abnormal temperature dependence of MoO<sub>4</sub> symmetric stretching vibration phonon modes (SSVPMs) reveal giant anharmonic phonon–phonon interaction in α-Al<sub>2</sub>Mo<sub>3</sub>O<sub>12</sub>. The ultralow thermal conductivity of α-Al<sub>2</sub>Mo<sub>3</sub>O<sub>12</sub> is predicted by the ultrashort phonon lifetime of ∼0.12 ps. Our findings provide insight into the thermal properties of α-Al<sub>2</sub>Mo<sub>3</sub>O<sub>12</sub> and are helpful for the application in polarization-sensitive optoelectronic detector and thermoelectric material.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"37 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143775885","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}
This study utilized a variety of in situ spectroscopic techniques to investigate the corrosion inhibition mechanism of three pyridine-based inhibitors on carbon steel in HCl and NaCl solutions. The results demonstrated that the adsorption and orientation of the inhibitor molecules play key roles in the corrosion inhibition mechanism studied using second harmonic generation (SHG). The number density of molecules adsorbed on the substrate is a crucial factor affecting the inhibition efficiency. A two-step physical model elucidates the SHG signal time evolution, revealing initial rapid inhibitor adsorption and subsequent slow dynamic adsorption optimization. Our research indicated that, in HCl solution, H+ protonates the pyridine inhibitors, and the protonated species adsorb onto the positively charged substrate bridging, forming a compact chemisorbed layer that effectively blocks corrosive ion access. In contrast, in NaCl solution, Cl– promotes the formation of a porous corrosion product film, which synergizes with adsorbed inhibitors to mitigate metal degradation. This finding offers insights into molecular-level interfacial inhibition mechanisms in environments with H+ and/or Cl– ions.
{"title":"In Situ Spectroscopies Unraveling the Molecular Mechanisms of H+ and Cl– on Pyridine Inhibition of Low-Carbon Steel Corrosion","authors":"Huihui Hu, Yuening Zhang, Peng Shang, Linyu Han, Rongjuan Feng, Xiaorui Ren, Dong Wang, Yuan Guo, Zhen Zhang","doi":"10.1021/acs.jpclett.5c00396","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c00396","url":null,"abstract":"This study utilized a variety of in situ spectroscopic techniques to investigate the corrosion inhibition mechanism of three pyridine-based inhibitors on carbon steel in HCl and NaCl solutions. The results demonstrated that the adsorption and orientation of the inhibitor molecules play key roles in the corrosion inhibition mechanism studied using second harmonic generation (SHG). The number density of molecules adsorbed on the substrate is a crucial factor affecting the inhibition efficiency. A two-step physical model elucidates the SHG signal time evolution, revealing initial rapid inhibitor adsorption and subsequent slow dynamic adsorption optimization. Our research indicated that, in HCl solution, H<sup>+</sup> protonates the pyridine inhibitors, and the protonated species adsorb onto the positively charged substrate bridging, forming a compact chemisorbed layer that effectively blocks corrosive ion access. In contrast, in NaCl solution, Cl<sup>–</sup> promotes the formation of a porous corrosion product film, which synergizes with adsorbed inhibitors to mitigate metal degradation. This finding offers insights into molecular-level interfacial inhibition mechanisms in environments with H<sup>+</sup> and/or Cl<sup>–</sup> ions.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"18 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143775881","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 : 2025-04-04DOI: 10.1021/acs.jpclett.5c00414
Xinzhe Wang, Percy Zahl, Miguel Wiche, Hailiang Wang, Eric I. Altman, Udo D. Schwarz
Supported cobalt phthalocyanines (CoPc) are promising catalysts for CO2 reduction, a critical process for mitigating greenhouse gas emissions. Enhancing the catalytic performance of CoPc involves modifying the interaction between the cobalt center and intermediate species. This study focuses on the effects of tert-butyl substitution on CoPc using (tert-butyl)4CoPc, where the substitution can both directly alter the molecule’s intramolecular electronic structure and indirectly alter it by the bulky group weakening the interaction with the support. Toward this end, we investigated the structural and chemical properties of (tert-butyl)4CoPc on a Ag(111) surface at the single-molecule level using three-dimensional atomic force microscopy (AFM) with a CO-terminated tip and discussed them in comparison with data for unmodified CoPc and amino-substituted CoPc. Notably, distance-dependent force measurements revealed anomalies in the tert-butyl groups’ force curves, attributed to their rotational flexibility. The tert-butyl (t-butyl) groups were also observed to increase the attraction of the central Co atom to CO, but this effect was attributed largely to enhanced interactions of the back of the tip with the peripheral t-butyl groups. While this longer-range interaction would not be expected to impact the interaction of small molecules with the catalytic center, the results reveal the ability of AFM to characterize longer range environmental interactions that can enhance adsorption and subsequent reactions of larger molecules, as well as the role side chains that offer configurational adaptability may play in these interactions.
{"title":"Effect of tert-Butyl Substitution on the Interactions of Cobalt Phthalocyanine with a Carbon Monoxide-Functionalized Tip","authors":"Xinzhe Wang, Percy Zahl, Miguel Wiche, Hailiang Wang, Eric I. Altman, Udo D. Schwarz","doi":"10.1021/acs.jpclett.5c00414","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c00414","url":null,"abstract":"Supported cobalt phthalocyanines (CoPc) are promising catalysts for CO<sub>2</sub> reduction, a critical process for mitigating greenhouse gas emissions. Enhancing the catalytic performance of CoPc involves modifying the interaction between the cobalt center and intermediate species. This study focuses on the effects of <i>tert</i>-butyl substitution on CoPc using (<i>tert</i>-butyl)<sub>4</sub>CoPc, where the substitution can both directly alter the molecule’s intramolecular electronic structure and indirectly alter it by the bulky group weakening the interaction with the support. Toward this end, we investigated the structural and chemical properties of (<i>tert</i>-butyl)<sub>4</sub>CoPc on a Ag(111) surface at the single-molecule level using three-dimensional atomic force microscopy (AFM) with a CO-terminated tip and discussed them in comparison with data for unmodified CoPc and amino-substituted CoPc. Notably, distance-dependent force measurements revealed anomalies in the <i>tert</i>-butyl groups’ force curves, attributed to their rotational flexibility. The <i>tert</i>-butyl (<i>t</i>-butyl) groups were also observed to increase the attraction of the central Co atom to CO, but this effect was attributed largely to enhanced interactions of the back of the tip with the peripheral <i>t</i>-butyl groups. While this longer-range interaction would not be expected to impact the interaction of small molecules with the catalytic center, the results reveal the ability of AFM to characterize longer range environmental interactions that can enhance adsorption and subsequent reactions of larger molecules, as well as the role side chains that offer configurational adaptability may play in these interactions.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"4 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143775882","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}
Chiral macrocyclic molecules are extensively investigated as potential candidates to develop organic emitters exhibiting circularly polarized luminescence (CPL) with large dissymmetry factors (g). Here, based on time-dependent density functional theory calculations, we investigate the relationship between macrocycle size and chiral properties. Our results underline that the rotatory strength (R) of the transition to the first excited state (S0 → S1) increases linearly with the macrocycle loop area. While this evolution could promote high g values in the case of very large rings, it is found that the increase in system size can lead to energetic quasi-degeneracy of several low-lying transitions. In large macrocycles, among those transitions, it is the slightly higher-energy transitions possessing large oscillator strengths but small g values that come to dominate over the S0 → S1 transition. Also, the corresponding decrease in energy spacing among these lowest excited states can trigger a broken symmetry of the S1-state geometry via a pseudo Jahn–Teller effect. Overall, our results highlight that in large macrocycles the CPL can gain in intensity but this occurs at the expense of the g value. Thus, it is critical that the interaction of the S0 → S1 transition with higher-energy states be carefully considered when designing large-size CPL emitters.
{"title":"Optical Properties of Macrocyclic Chiral Molecules: The Limitations of Ring Size Increase","authors":"Gjergji Sini, Qi Sun, Eunkyung Cho, Jean-Luc Brédas, Veaceslav Coropceanu","doi":"10.1021/acs.jpclett.5c00690","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c00690","url":null,"abstract":"Chiral macrocyclic molecules are extensively investigated as potential candidates to develop organic emitters exhibiting circularly polarized luminescence (CPL) with large dissymmetry factors (<i>g</i>). Here, based on time-dependent density functional theory calculations, we investigate the relationship between macrocycle size and chiral properties. Our results underline that the rotatory strength (<i>R</i>) of the transition to the first excited state (S<sub>0</sub> → S<sub>1</sub>) increases linearly with the macrocycle loop area. While this evolution could promote high <i>g</i> values in the case of very large rings, it is found that the increase in system size can lead to energetic quasi-degeneracy of several low-lying transitions. In large macrocycles, among those transitions, it is the slightly higher-energy transitions possessing large oscillator strengths but small <i>g</i> values that come to dominate over the S<sub>0</sub> → S<sub>1</sub> transition. Also, the corresponding decrease in energy spacing among these lowest excited states can trigger a broken symmetry of the S<sub>1</sub>-state geometry via a pseudo Jahn–Teller effect. Overall, our results highlight that in large macrocycles the CPL can gain in intensity but this occurs at the expense of the <i>g</i> value. Thus, it is critical that the interaction of the S<sub>0</sub> → S<sub>1</sub> transition with higher-energy states be carefully considered when designing large-size CPL emitters.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"73 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143782886","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 : 2025-04-04DOI: 10.1021/acs.jpclett.4c03601
Wei Lu Wang, Chen Yang Gong, Si Jie Guo, Zhong Fan, Yong Bin Wu, Shuang Liu, Yang He, Guang Ming Jiang, Jin Zhong Zhang
A series of Au1Agx alloys (x = 0, 0.2, 0.3, 1.0, and 3.0) supported over SiO2 has been prepared and pretreated via different atmospheric processes. The physical–chemical properties of these materials have been systematically characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible (UV–vis) spectroscopy, and transmission electron microscopy (TEM). The results reveal that oxygen species are doped into the alloy structure by the oxygen-involved pretreatment, leading to lattice expansion as well as a significant increase in catalytic activity. Improvement in the catalytic activity of Au1Ag0.3/SiO2 through sequential reduction and oxidation pretreatment was evidenced by a decrease in the temperature of 100% CO conversion by approximately 500 K. A volcano trend in catalytic activity is found as the Ag composition is increased in the alloy structure. Density-functional theory (DFT) calculations suggest that the introduced oxygen species are likely present at the subsurface of the AuAg alloy and involved in the reaction or in modifying the electronic structure of surface Ag, thereby enhancing the catalytic activity for CO oxidation.
{"title":"Oxygen Species Enhanced Catalytic Efficiency of Au1Agx/SiO2 Catalysts for CO Oxidation","authors":"Wei Lu Wang, Chen Yang Gong, Si Jie Guo, Zhong Fan, Yong Bin Wu, Shuang Liu, Yang He, Guang Ming Jiang, Jin Zhong Zhang","doi":"10.1021/acs.jpclett.4c03601","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03601","url":null,"abstract":"A series of Au<sub>1</sub>Ag<sub><i>x</i></sub> alloys (<i>x</i> = 0, 0.2, 0.3, 1.0, and 3.0) supported over SiO<sub>2</sub> has been prepared and pretreated via different atmospheric processes. The physical–chemical properties of these materials have been systematically characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible (UV–vis) spectroscopy, and transmission electron microscopy (TEM). The results reveal that oxygen species are doped into the alloy structure by the oxygen-involved pretreatment, leading to lattice expansion as well as a significant increase in catalytic activity. Improvement in the catalytic activity of Au<sub>1</sub>Ag<sub>0.3</sub>/SiO<sub>2</sub> through sequential reduction and oxidation pretreatment was evidenced by a decrease in the temperature of 100% CO conversion by approximately 500 K. A volcano trend in catalytic activity is found as the Ag composition is increased in the alloy structure. Density-functional theory (DFT) calculations suggest that the introduced oxygen species are likely present at the subsurface of the AuAg alloy and involved in the reaction or in modifying the electronic structure of surface Ag, thereby enhancing the catalytic activity for CO oxidation.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"108 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143775878","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}
Small molecule material spiro-OMeTAD is widely employed as the hole transport layer (HTL) in efficient n-i-p perovskite solar cells (PSCs). However, the intrinsic poor conductivity and hole mobility of spiro-OMeTAD, coupled with its strong hygroscopic nature, severely limit the performance and lifetime of the devices. Herein, we employ a low-cost 1,4-benzenedithiol (BDT) additive to overcome the limits of pristine spiro-OMeTAD. BDT doping in spiro-OMeTAD can increase the carrier mobility and electrical conductivity. Meanwhile, because of the sulfhydryl group in BDT, the hygroscopic nature of spiro-OMeTAD is decreased. Furthermore, the trap-state density and defect-induced nonradiative recombination of the BDT-doped device are decreased. Additionally, the improved energy level alignment between the HTL and the perovskite layer facilitates more efficient hole transport. Consequently, the rigid PSC and flexible PSC doped with BDT achieve champion power conversion efficiencies (PCEs) of 22.34% and 21.04%, respectively, surpassing the PCEs of 20.83% and 19.64% obtained from the original rigid PSC and flexible PSC, respectively. Furthermore, the BDT-based devices exhibit better stability than control devices.
{"title":"Spiro-OMeTAD with a 1,4-Benzenedithiol Additive to Promote High-Performance Perovskite Solar Cells","authors":"Yang Hao, Jingkun Ren, Mengxue Sun, Yuan Li, Yanan Liu, Wenqiang Li, Yuying Hao","doi":"10.1021/acs.jpclett.5c00428","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c00428","url":null,"abstract":"Small molecule material spiro-OMeTAD is widely employed as the hole transport layer (HTL) in efficient n-i-p perovskite solar cells (PSCs). However, the intrinsic poor conductivity and hole mobility of spiro-OMeTAD, coupled with its strong hygroscopic nature, severely limit the performance and lifetime of the devices. Herein, we employ a low-cost 1,4-benzenedithiol (BDT) additive to overcome the limits of pristine spiro-OMeTAD. BDT doping in spiro-OMeTAD can increase the carrier mobility and electrical conductivity. Meanwhile, because of the sulfhydryl group in BDT, the hygroscopic nature of spiro-OMeTAD is decreased. Furthermore, the trap-state density and defect-induced nonradiative recombination of the BDT-doped device are decreased. Additionally, the improved energy level alignment between the HTL and the perovskite layer facilitates more efficient hole transport. Consequently, the rigid PSC and flexible PSC doped with BDT achieve champion power conversion efficiencies (PCEs) of 22.34% and 21.04%, respectively, surpassing the PCEs of 20.83% and 19.64% obtained from the original rigid PSC and flexible PSC, respectively. Furthermore, the BDT-based devices exhibit better stability than control devices.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"43 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143775883","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 : 2025-04-04DOI: 10.1021/acs.jpclett.5c00631
So Hirata
Ab initio electronic structure theory has transformed gas-phase molecular science with its predictive ability. In the attempt to bring such predictive ability to macroscopic systems and condensed matter, the theory must integrate quantum mechanics with statistical thermodynamics so that thermodynamic functions such as free energy, internal energy, entropy, and chemical potentials are computed as functions of temperature in a systematically converging series of approximations. A general, versatile strategy of elevating any ab initio electronic structure theory to nonzero temperatures is introduced and discussed.
{"title":"New Dimension in Ab Initio Electronic Structure Theory: Temperature, Pressure, and Chemical Potential","authors":"So Hirata","doi":"10.1021/acs.jpclett.5c00631","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c00631","url":null,"abstract":"<i>Ab initio</i> electronic structure theory has transformed gas-phase molecular science with its predictive ability. In the attempt to bring such predictive ability to macroscopic systems and condensed matter, the theory must integrate quantum mechanics with statistical thermodynamics so that thermodynamic functions such as free energy, internal energy, entropy, and chemical potentials are computed as functions of temperature in a systematically converging series of approximations. A general, versatile strategy of elevating any <i>ab initio</i> electronic structure theory to nonzero temperatures is introduced and discussed.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"58 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143775886","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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