{"title":"What Is a Good Simulant for Plutonium(III) in Molten Chloride Salts?","authors":"Kateryna Goloviznina, Mathieu Salanne","doi":"10.1021/acs.jpcb.5c03702","DOIUrl":"10.1021/acs.jpcb.5c03702","url":null,"abstract":"<p><p>Despite the importance of plutonium compounds in the nuclear energy industry, their properties have rarely been studied directly. This is due to the artificial character as well as the high radioactivity level of this element. Instead, simulants with close physicochemical properties are used, such as cerium(IV) or thorium(IV), for oxide fuel properties. Under the molten chloride salt reactor conditions, Pu, Ce, and Th, respectively, are at the +III, +III, and +IV oxidation states, so that Ce(III) is generally favored. Our work analyzes the relevance of this choice based on quantum chemistry calculations and molecular dynamics (MD) simulations. Using density functional theory, we first demonstrate that among the lanthanide series, the neodymium(III) cation has the most similar interaction with chloride anions when compared to the ones involving Pu(III). Then, we compare the physical and thermodynamic properties as well as the local structure of NaCl-NdCl<sub>3</sub>, NaCl-CeCl<sub>3</sub>, and NaCl-PuCl<sub>3</sub> mixtures close to the eutectic composition that could be used as nuclear fuel using MD simulations. For all the elements, a polarizable force field obtained using the same procedure is used. The results confirm Nd(III) as the best choice to simulate the properties of Pu(III) with the greatest accuracy, and they allow the estimation of the error made when using Ce(III) instead.</p>","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":" ","pages":"7826-7830"},"PeriodicalIF":2.9,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144688333","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}
Alexander E. Khudozhitkov, Peter Stange, Alexander G. Stepanov, Daniel Schröder, Daniel Rauber, Frederik Philippi, Daniil I. Kolokolov* and Ralf Ludwig*,
{"title":"","authors":"Alexander E. Khudozhitkov, Peter Stange, Alexander G. Stepanov, Daniel Schröder, Daniel Rauber, Frederik Philippi, Daniil I. Kolokolov* and Ralf Ludwig*, ","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":"129 30","pages":"XXX-XXX XXX-XXX"},"PeriodicalIF":2.9,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acs.jpcb.5c02460","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144737801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Nonconventional Luminescence of Halogenated Silanes: Mechanistic Insight.","authors":"Xiangxi Zhang, Feng Jin, Xintong Li, Jun Wang, Qing Zhou, LingminYi","doi":"10.1021/acs.jpcb.5c03897","DOIUrl":"10.1021/acs.jpcb.5c03897","url":null,"abstract":"<p><p>In this study, the luminescence properties and emission mechanisms of five halogenated silanes, hexamethyldisiloxane (HT), chloromethylsilane (CT), iodomethylsilane (IT), chlorosilane (CS), and 1<i>H</i>,1<i>H</i>,2<i>H</i>,2<i>H</i>-perfluorooctyltrimethoxysilane (FS) are systematically investigated. The effects of halogen type, substitution position, and temperature on luminescence efficiency, Stokes shift, and phosphorescence lifetime are elucidated through fluorescence, phosphorescence analysis, and theoretical calculations (at room temperature and 77 K). The results revealed that CS exhibits excellent fluorescence emission at 365 nm and significantly prolonged low-temperature phosphorescence lifetime due to its reduced nonradiative transitions and minimized excited-state energy dissipation. IT exhibited enhanced phosphorescence under liquid nitrogen, which can be attributed to the heavy-atom effect of the iodine atom and strong spin-orbit coupling. The Stokes shift analysis of excitation-emission spectra demonstrated that the energy gap between the excited and ground states can be reduced by the substituted halogen atoms. Moreover, CS displays the smallest shift among the five halogenated silanes, and its maximum emission wavelength is red-shifted with induced temperature, reflecting increased energy dissipation. The electron-hole distribution analysis confirms that halogens regulate luminescence efficiency by modulating electron transfer pathways (from high-electronegativity atoms to low-electronegativity regions) and spin-coupling strength. This work not only enriches the understanding of nonconventional luminescence in pure liquids but also provides theoretical foundations for the design of high-performance silicon-based optoelectronic materials.</p>","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":" ","pages":"7852-7860"},"PeriodicalIF":2.9,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144657824","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}
Rui Ye, Yuxuan Yang, Kevin C Chan, Dong Zhang, Ruhong Zhou
{"title":"<i>In Silico</i> Design of High-Affinity gp100 Antigenic Mimotopes for Targeting Melanoma.","authors":"Rui Ye, Yuxuan Yang, Kevin C Chan, Dong Zhang, Ruhong Zhou","doi":"10.1021/acs.jpcb.5c01507","DOIUrl":"10.1021/acs.jpcb.5c01507","url":null,"abstract":"<p><p>Human CD8+ cytotoxic T lymphocytes (CTLs) induce melanoma regression by utilizing T-cell receptors (TCRs) to recognize tumor-specific epitopes. One such epitope, gp100<sub>280-288(288 V)</sub> (YLEPGPVTV), is presented by human leukocyte antigen (HLA)-A*02:01 molecules. Computational approaches, particularly the predictions on peptide-HLA (pHLA) and TCR-pHLA binding affinities, are complementary to experimental approaches in guiding further optimization and design of the gp100<sub>280-288(288 V)</sub> peptide (mimotopes) for enhanced antitumor responses. Here, with all-atom molecular dynamics (MD) simulations and free energy perturbation (FEP) methods, we designed a series of potential mimotopes through <i>in silico</i> mutagenesis studies of gp100<sub>280-288(288 V)</sub> utilizing the latest affinity-matured TCR structure. Our results showed that E3I and E3L mutants increased HLA binding without affecting TCR binding, indicating their potential as epitope candidates. Conversely, the E3A and E3V mutations improved peptide-HLA binding but weakened the TCR-pHLA binding affinity. In-depth structural analysis revealed that insufficient occupancy of the HLA pocket by residue 3 in the E3A and E3V mutants would induce a twisted peptide conformation at positions 4 to 6, disrupting the interaction between TCR and pHLA. Therefore, it is crucial to consider the impact of single-residue mutations that alter peptide conformation on TCR binding when designing effective antigenic mimotopes. Furthermore, the E3I+V7L and E3L+V7L double mutants are also found to produce favorable binding affinity changes similar to those of the E3I and E3L mutants, suggesting their potential as advantageous mimotope candidates. Our work provides structural insights for the rational design of favorable gp100 mimotopes and may contribute to developing gp100 epitope-based vaccines.</p>","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":" ","pages":"7708-7718"},"PeriodicalIF":2.9,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144681683","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":"Autobiography of Charles L. Brooks III.","authors":"Charles L Brooks","doi":"10.1021/acs.jpcb.5c04353","DOIUrl":"https://doi.org/10.1021/acs.jpcb.5c04353","url":null,"abstract":"","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":"129 30","pages":"7701-7707"},"PeriodicalIF":2.9,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144751888","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}