化学•材料最新文献

{"title":"Comment on “Localized and Delocalized States of a Diamine Cation: Resolution of a Controversy”","authors":"Gabriel S. Phun, Bryan M. Wong","doi":"10.1021/acs.jpclett.4c01984","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c01984","url":null,"abstract":"Since its appearance in [Cheng, X.; Zhang, Y.; Jónsson,\u0000E.; Jónsson, H.; Weber, P. M. <cite><i>Nat. Commun.</i></cite> <span>2016</span>, <em>7</em>, 11013] and recent re-investigation in [Gałyńska,\u0000M.; Ásgeirsson, V.; Jónsson, H.; Bjornsson, R. <cite><i>J. Phys. Chem. Lett.</i></cite>, <span>2021</span>, <em>12</em>, 1250−1255], the dimethylpiperazine cation (DMP⁺) has generated considerable discussion and controversy in the scientific literature over the existence of stable, local energy minima in this molecular system. Specifically, prior assumptions that the Rydberg state and radical cation of DMP are similar have led to significant confusion and debate regarding the accuracy of various quantum chemistry methods and the existence of stable configurations of DMP⁺ itself. The purpose of this Viewpoint is to highlight recent studies that call into question the main findings in the previously mentioned works as well as present new CCSDT (Coupled-Cluster with Single, Double, and Triple excitations) calculations to finally bring closure to this controversy.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":6.475,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610040","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":"Ultrafast Spectroscopic Investigation of the Aggregation Induced TADF from High-Level Reversed Intersystem Crossing","authors":"Ziqi Deng, Yunfeng Luo, Guanheng Huang, Jiaxing He, David Lee Phillips","doi":"10.1021/acs.jpclett.4c02395","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c02395","url":null,"abstract":"The thermally activated delayed fluorescence (TADF) originating from high-level intersystem crossing (hRISC) presents great potential in realizing a more full utilization of triplet excitons. In this study, DPA-FBP and TPA-FBP were doped in a PMMA film with different weight fractions to study the effect of aggregation on the luminescence properties. As a result, the TADF feature from hRISC was only found in the 50 wt % doped film, whereas the 1 wt % doped film only shows prompt fluorescence. The fs-TA spectroscopy results reveal that the 50 wt % film will generate charge transfer species to lower the energy gap, so that the high-lying triplet exciton can transition back to the singlet state, whereas that of the 1 wt % film will quickly transition to the lowest triplet state due to the unfavorable energy splitting. This study provides a new insight into aggregation effects on the excited-state properties of hot exciton materials and the solid-state photodynamic.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":6.475,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610033","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":"Photothermal Spectroscopy in Attenuated Total Internal Reflection Geometry by Polarization Rotation and Deflection","authors":"Mythreyi Rayaluru, Anwesha Maitra, Anuj K. Pennathur, Jahan M. Dawlaty","doi":"10.1021/acs.jpcc.4c04873","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c04873","url":null,"abstract":"Photothermal spectroscopy has proven to be an incisive analytical tool, with several offshoots and applications. It is desirable to extend this technique to interfacial spectroscopy to further broaden its scope. Toward that goal, we demonstrate photothermal infrared (IR) spectroscopy where a resonant IR beam heats an interface, while a visible beam probes the interface in the attenuated total internal reflection (ATR) geometry. The photothermal spectra of a test molecule show similar concentration dependence and solvatochromic shifts when compared to FTIR-ATR measurements. We also show that two mechanisms underpin the ATR photothermal signal. The first mechanism is polarization change of the probe beam due to the thermal refractive index change of the interface. This is confirmed by time-dependent changes in the polarization state of the probe beam due to heating. The second mechanism is deflection of the probe beam upon heating by the IR pump. Furthermore, we showed that the photothermal effect persists when a thin film of gold is added to the interface. Our work will open potential applications of this technique in interfacial sciences and electrochemistry and will guide new approaches to reach monolayer sensitivity.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610041","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":"Facile Synthesis of Trimetallic Hexoctahedral Au@PdPt Nanoparticles for Electrocatalytic Oxidation of Methanol","authors":"Cuixia Bi, Xiaolong Yin, Zhixiu Wang, Hongyan Zhao, Guangqiang Liu","doi":"10.1021/acs.jpcc.4c06337","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c06337","url":null,"abstract":"In this study, trimetallic Au@PdPt nanoparticles (NPs) were synthesized by a seed-mediated technique, possessing a hexoctahedral (HOH) Au core with a branched PdPt alloy shell. The fabrication process involved the synthesis of HOH Au NPs exhibiting high-index {651} facet as nanotemplates, followed by the epitaxial growth of Pd and Pt on these NPs to yield HOH Au@PdPt NPs. The size and composition of HOH Au@PdPt NPs as well as the thickness of PdPt alloy shells (from 2 to 4, 5, and 8 nm) can be precisely adjusted by varying the quantity of Pd and Pt precursors. The catalytic efficacy of these Au@PdPt NPs was significantly enhanced through the synergistic effect between Au, Pd, and Pt, along with the increased contact areas afforded by multibranched PdPt alloy shells. For methanol electro-oxidation, the catalytic activity of HOH Au@PdPt NPs depends on the Pt content showing a distinctive volcano-type pattern. Remarkably, the HOH Au@Pd_0.3Pt_0.3 NPs demonstrate optimum catalytic performance for methanol oxidation in acidic conditions, exhibiting superior electrocatalytic properties compared to commercial Pt black catalysts. Their ECSA value, mass, and specific activities are 47.21 m² g^–1, 0.93 A mg^–1, and 1.97 mA cm^–2, respectively. This research can be exploited to fabricate catalysts possessing exceptional properties by precisely designing and controlling the size, composition and morphology of the trimetallic Au@PdPt NPs.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610045","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":"Probing Functional Allosteric States and Conformational Ensembles of the Allosteric Protein Kinase States and Mutants: Atomistic Modeling and Comparative Analysis of AlphaFold2, OmegaFold, and AlphaFlow Approaches and Adaptations.","authors":"Nishank Raisinghani, Mohammed Alshahrani, Grace Gupta, Hao Tian, Sian Xiao, Peng Tao, Gennady Verkhivker","doi":"10.1021/acs.jpcb.4c04985","DOIUrl":"10.1021/acs.jpcb.4c04985","url":null,"abstract":"<p><p>This study reports a comprehensive analysis and comparison of several AlphaFold2 adaptations and OmegaFold and AlphaFlow approaches in predicting distinct allosteric states, conformational ensembles, and mutation-induced structural effects for a panel of state-switching allosteric ABL mutants. The results revealed that the proposed AlphaFold2 adaptation with randomized alanine sequence scanning can generate functionally relevant allosteric states and conformational ensembles of the ABL kinase that qualitatively capture a unique pattern of population shifts between the active and inactive states in the allosteric ABL mutants. Consistent with the NMR experiments, the proposed AlphaFold2 adaptation predicted that G269E/M309L/T408Y mutant could induce population changes and sample a significant fraction of the fully inactive I₂ form which is a low-populated, high-energy state for the wild-type ABL protein. We also demonstrated that other ABL mutants G269E/M309L/T334I and M309L/L320I/T334I that introduce a single activating T334I mutation can reverse equilibrium and populate exclusively the active ABL form. While the precise quantitative predictions of the relative populations of the active and various hidden inactive states in the ABL mutants remain challenging, our results provide evidence that AlphaFold2 adaptation with randomized alanine sequence scanning can adequately detect a spectrum of the allosteric ABL states and capture the equilibrium redistributions between structurally distinct functional ABL conformations. We further validated the robustness of the proposed AlphaFold2 adaptation for predicting the unique inactive architecture of the BSK8 kinase and structural differences between ligand-unbound apo and ATP-bound forms of BSK8. The results of this comparative study suggested that AlpahFold2, OmegaFold, and AlphaFlow approaches may be driven by structural memorization of existing protein folds and are strongly biased toward predictions of the thermodynamically stable ground states of the protein kinases, highlighting limitations and challenges of AI-based methodologies in detecting alternative functional conformations, accurate characterization of physically significant conformational ensembles, and prediction of mutation-induced allosteric structural changes.</p>","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142562603","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":"Assessing the Influence of Illumination on Ion Conductivity in Perovskite Solar Cells.","authors":"Andreas Schiller, Sandra Jenatsch, Balthasar Blülle, Miguel Angel Torre Cachafeiro, Firouzeh Ebadi, Nasim Kabir, Mostafa Othman, Christian Michael Wolff, Aïcha Hessler-Wyser, Christophe Ballif, Wolfgang Tress, Beat Ruhstaller","doi":"10.1021/acs.jpclett.4c02403","DOIUrl":"10.1021/acs.jpclett.4c02403","url":null,"abstract":"<p><p>Whether illumination influences the ion conductivity in lead-halide perovskite solar cells containing iodide halides has been an ongoing debate. Experiments to elucidate the presence of a photoconductive effect require special devices or measurement techniques and neglect possible influences of the enhanced electronic charge concentrations. Here, we assess the electronic-ionic charge transport using drift-diffusion simulations and show that the well-known increase in capacitance at low frequencies under illumination is caused by electronic currents that are amplified due to the screening of the alternating electric field by the ions. We propose a novel characterization technique to detect a potential photoinduced increase in ionic conductivity based on capacitance measurements on fully integrated devices. The method is applied to a range of perovskite solar cells with different active layer materials. Remarkably, all measured samples show a clear signature of photoenhanced ion conductivity, posing fundamental questions on the underlying nature of the photosensitive mechanism.</p>","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142563543","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":"Highly Accurate and Robust Constraint-Based Orbital-Optimized Core Excitations.","authors":"Yannick Lemke, Jörg Kussmann, Christian Ochsenfeld","doi":"10.1021/acs.jpca.4c04139","DOIUrl":"10.1021/acs.jpca.4c04139","url":null,"abstract":"<p><p>We adapt our recently developed constraint-based orbital-optimized excited-state method (COOX) for the computation of core excitations. COOX is a constrained density functional theory (cDFT) approach based on excitation amplitudes from linear-response time-dependent DFT (LR-TDDFT), and has been shown to provide accurate excitation energies and excited-state properties for valence excitations within a spin-restricted formalism. To extend COOX to core-excited states, we introduce a spin-unrestricted variant which allows us to obtain orbital-optimized core excitations with a single constraint. Using a triplet purification scheme in combination with the constrained unrestricted Hartree-Fock formalism, scalar-relativistic zero-order regular approximation corrections, and a semiempirical treatment of spin-orbit coupling, COOX is shown to produce highly accurate results for K- and L-edge excitations of second- and third-period atoms with subelectronvolt errors despite being based on LR-TDDFT, for which core excitations pose a well-known challenge. L- and M-edge excitations of heavier atoms up to uranium are also computationally feasible and numerically stable, but may require more advanced treatment of relativistic effects. Furthermore, COOX is shown to perform on par with or better than the popular ΔSCF approach while exhibiting more robust convergence, highlighting it as a promising tool for inexpensive and accurate simulations of X-ray absorption spectra.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142575444","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":"Hybrid-DFT Molecular Dynamics Simulations of Photocatalytic Water Oxidation in a [Ru-bda]–Dye Complex","authors":"Titus de Haas, Dario Calvani, Aegir Zaaruolo, Tjeerd de Jong, Jonas Rutgers, Bas Kreupeling, Huub J. M. de Groot, Francesco Buda","doi":"10.1021/acs.jpcc.4c05104","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c05104","url":null,"abstract":"In the past decade, Ru-bda (bda = 2,2′-bipyridine-6,6′-dicarboxylic acid) complexes have emerged as extremely effective water oxidation catalysts, rendering them a potential candidate for incorporation into dye-sensitized photoelectrochemical cells. However, the performance of these catalysts declines dramatically when anchored to a photoanode surface due to their catalytic mechanism involving the interaction of two metal centers (I2M). This reduced performance prompts an investigation into the catalytic cycle following an alternative mechanism in which the O–O bond is formed through a water nucleophilic attack (WNA). In this work, we have performed hybrid-DFT based molecular dynamics simulations of the rate-determining O–O bond formation following the WNA mechanism in a [Ru-bda]–dye dyad model in explicit water solvation. In addition, our study probes oxygen dissociation from the Ru^III–O₂ intermediate, and the equilibrium dynamics of the low-valent Ru^III–bda intermediate. Our simulations demonstrate that including a fraction of exact Hartree–Fock exchange impacts the electron and hole localizations in the catalyst–dye complex, which can in specific instances affect the dynamics of the system. This study contributes to a fundamental understanding of water oxidation catalysis with the Ru-bda catalyst family and highlights the relevance of modeling catalytic processes at the hybrid-DFT level.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610042","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":"Understanding the Correlation of the Quantum Dephasing Time and Entangled Photon Interaction in Crystalline Tetracene Derivatives","authors":"Olusayo J. Ogunyemi, Chanchal Rani, Oleg Varnavski, Rumaisa Wajahath, Michael Norscia, Brock Malaikal, Yunfan Qiu, Shichao Sun, Yonghao Gu, Shaul Mukamel, Michael R. Wasielewski, Theodore Goodson, III","doi":"10.1021/acs.jpcc.4c05907","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c05907","url":null,"abstract":"Quantum-to-quantum transduction is the coherent exchange of information between quantum systems, which is an essential element of quantum information science (QIS). Molecular architectures provide unmatched flexibility for tailoring the properties that are critical to quantum transduction, and molecular synthesis affords the opportunity to build novel molecular materials from the bottom-up. Singlet fission (SF) in organic chromophore solids provides a potential means of executing photon-to-spin quantum transduction because absorption of a single photon results in formation of four entangled spins that constitute a triplet pair state (TT). We have demonstrated that SF in single crystals of 5,12-bis(tricyclohexylsilylethynyl)-tetracene (TCHS-tetracene) produces a long-lived quintet state ⁵(TT) that provides a promising new route to multiqubit systems for QIS. Here, we investigate the interaction of classical and entangled photons with TCHS-tetracene as well as the related TIPS-tetracene and tetracene to assess the molecular properties required for quantum transduction. From the classical two-photon absorption (TPA) experiment, we observed that TCHS-tetracene and TIPS-tetracene have a higher TPA cross-section than tetracene. The entangled TPA cross-sections of TCHS-tetracene and TIPS-tetracene (6.914 × 10^–19 and 5.057 × 10^–19 cm²/molecule, respectively) are about an order of magnitude larger than that of tetracene (5.146 × 10^–20 cm²/molecule), making TCHS-tetracene and TIPS-tetracene excellent candidates for demonstrating photon-to-spin transduction using SF. We also observed a longer coherence time for the TCHS-tetracene in comparison to the tetracene molecular systems investigated, which suggests its suitability for possible QIS applications.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610044","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":"Geometric Frustration Directs the Self-assembly of Nanoparticles with Crystallized Ligand Bundles.","authors":"Federico Tomazic, Aswathy Muttathukattil, Afshin Nabiyan, Felix Schacher, Michael Engel","doi":"10.1021/acs.jpcb.4c04562","DOIUrl":"10.1021/acs.jpcb.4c04562","url":null,"abstract":"<p><p>Polymer-grafted nanoparticles are versatile building blocks that self-assemble into a diverse range of mesostructures. Coarse-grained molecular simulations have commonly accompanied experiments by resolving structure formation pathways and predicting phase behavior. Past simulations represented nanoparticles as spheres and the ligands as flexible chains of beads, isotropically tethered to the nanoparticles. Here, we investigate a different minimal coarse-grained model. The model consists of an attractive rod tethered to a repulsive sphere. The motivation of this rod-sphere model is to describe nanospheres with a partially crystallized, stretched polymeric bundle as well as other complex building blocks such as rigid surfactants and end-tethered nanorods. Varying the ratio of sphere size to rod radius stabilizes self-limited clusters and other mesostructures with reduced dimensionality. The complex phase behavior we observe is a consequence of geometric frustration.</p>","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142542922","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}