ChemphyschemPub Date : 2025-01-27DOI: 10.1002/cphc.202401098
Marek Freindorf, Kevin Fleming, Elfi Kraka
{"title":"Iron-Histidine Coordination in Cytochrome b5: A Local Vibrational Mode Study.","authors":"Marek Freindorf, Kevin Fleming, Elfi Kraka","doi":"10.1002/cphc.202401098","DOIUrl":"10.1002/cphc.202401098","url":null,"abstract":"<p><p>For a series of cytochrome b5 proteins isolated from various species, including bacteria, animals, and humans, we analyzed the intrinsic strength of their distal/proximal FeN bonds and the intrinsic stiffness of their axial NFeN bond angles. To assess intrinsic bond strength and bond angle stiffness, we employed local vibrational stretching force constants k<sup>a</sup>(FeN) and bending force constants k<sup>a</sup>(NFeN) derived from the local mode theory developed by our group; the ferric and ferrous oxidation states of the heme Fe were considered. All calculations were conducted with the QM/MM methodology. We found that the reduction of the heme Fe from the ferric to the ferrous state makes the FeN axial bonds weaker, longer, less covalent, and less polar. Additionally, the axial NFeN bond angle becomes stiffer and less flexible. Local mode force constants turned out to be far more sensitive to the protein environment than geometries; evaluating force constant trends across diverse protein groups and monitoring changes in the axial heme-framework revealed redox-induced changes to the primary coordination sphere of the protein. These results indicate that local mode force constants can serve as useful feature data for training machine learning models that predict cytochrome b5 redox potentials, which currently rely more on geometric data and qualitative descriptors of the protein environment. The insights gained through our investigation also offer valuable guidance for strategically fine-tuning artificial cytochrome b5 proteins and designing new, versatile variants.</p>","PeriodicalId":9819,"journal":{"name":"Chemphyschem","volume":" ","pages":"e202401098"},"PeriodicalIF":2.3,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143051760","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":"Exploring Surface State and Exciplex Dominated Aggregation Induced Electrochemiluminescence of Graphene Quantum Dots Prepared via Electrochemical Exfoliation.","authors":"Congyang Zhang, Zhenzhong Cai, Kenneth Chu, Wai-Tung Shiu, Ping Hu, Lijia Liu, Qiao Zhang, Zhifeng Ding","doi":"10.1002/cphc.202401074","DOIUrl":"10.1002/cphc.202401074","url":null,"abstract":"<p><p>Graphene quantum dots (GQDs) have emerged as promising materials for electrochemiluminescence (ECL) applications due to their unique optical and electronic properties. In this study, GQDs were synthesized via electrochemical exfoliation of graphite in a constant current density mode, enabling scalable production with controlled size and surface functionalization. GQDs-4 and GQDs-20, synthesized at applied current densities of 4 mA/cm<sup>2</sup> and 20 mA/cm<sup>2</sup> to the graphite electrode, respectively, were investigated on roles of surface states and exciplex dominated aggregation-induced emission (AIE) in their ECL performance. GQDs-4 obtained an absolute ECL quantum efficiency of 0.0012 %±0.0002 %. GQDs-20, with a smaller particle size, achieved an absolute ECL quantum efficiency of 0.028±0.002 %, demonstrating high efficiency in converting electrons into photons. While GQDs-4 exhibited minor intensity in PL and ECL, they displayed a similar emission spectrum to GQDs-20 in the ECL process. This finding highlights the significant role of surface states and AIE in influencing the emission properties of GQDs, independent from core-state transitions. These results provide critical insights into the mechanisms governing GQD-based ECL and offer pathways for optimizing these materials for use in biosensing, optoelectronics, and imaging applications. Keywords: Electrochemiluminescence, Graphene Quantum Dots, Exciplex, Surface States, Multi-color Emission.</p>","PeriodicalId":9819,"journal":{"name":"Chemphyschem","volume":" ","pages":"e202401074"},"PeriodicalIF":2.3,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143045643","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 Effects of Edge Planes in Porous Carbon: Quantum Capacitance and Electrolyte Behavior in Supercapacitor.","authors":"Guipei Xu, Zonglin Yi, Hao Liu, Jiewen Lai, Huifang Di, Yifeng Lu, Hui Huang, Zhenbing Wang","doi":"10.1002/cphc.202401006","DOIUrl":"10.1002/cphc.202401006","url":null,"abstract":"<p><p>Electric double layer capacitors (EDLC) require large specific surface area to provide high power density. The generation of pores increases the electrochemical capacitance with more graphitic edge planes exposed to the electrolyte. Conventional theory believes this increasing in capacitance is owed to the increased specific surface area, but our work uncovers another mechanism. DFT calculations discover the commonly seen defect-free zigzag and armchair edges can increase the quantum capacitance (C<sub>Q</sub>) due to their high chemical activity. Meanwhile, high chemical activity makes defect-free edges interact with electrolyte molecules more easily, leading to the potential reduce of electrolyte stabilization and the change on the origin mechanism of double layer capacitance (C<sub>D</sub>). Additionally, edges with non-hexagonal defects show a better balance between high C<sub>Q</sub> and electrolyte stability. Therefore, our discovery proves the preservation of non-hexagonal defects in edge planes through possible temperature controlling in heat treatment is important in reaching high electrochemical properties for EDLC.</p>","PeriodicalId":9819,"journal":{"name":"Chemphyschem","volume":" ","pages":"e202401006"},"PeriodicalIF":2.3,"publicationDate":"2025-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143045647","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}
ChemphyschemPub Date : 2025-01-25DOI: 10.1002/cphc.202400955
Qianyu He, Mengke Li, Shi-Jian Su
{"title":"Spectral Narrowing Strategies in Multiple Resonance Thermally Activated Delayed Fluorescence Materials.","authors":"Qianyu He, Mengke Li, Shi-Jian Su","doi":"10.1002/cphc.202400955","DOIUrl":"10.1002/cphc.202400955","url":null,"abstract":"<p><p>Multi-resonance thermally activated delayed fluorescence (MR-TADF) materials possess unique advantages of high-efficiency and narrowband emission, which have rapidly occupied an important position in the field of organic light-emitting diodes (OLEDs). In recent years, significant advancements have been made in the development of MR-TADF materials, particularly in achieving spectral narrowing for high-color-purity OLED applications. Based on diverse MR-TADF molecular skeletons, this review summarizes the primary molecular strategies to narrow spectrum by suppressing structural relaxation and intermolecular interactions. Key strategies include π-conjugation extension, increased molecular rigidity, and the introduction of bulky substituents and intramolecular hydrogen bonds. Additionally, effects of these strategies on photophysical properties are discussed. These molecular design strategies are expected to offer valuable insights for the future design of high-efficiency, narrowband OLED emitters.</p>","PeriodicalId":9819,"journal":{"name":"Chemphyschem","volume":" ","pages":"e202400955"},"PeriodicalIF":2.3,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143045645","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}
ChemphyschemPub Date : 2025-01-24DOI: 10.1002/cphc.202400882
Rui Sun, Bo Jin, Jinzhong Zhao, Xin Wu, Caixia Yuan
{"title":"Planar Pentacoordinate Bromine in Global Minimum Br6Li5.","authors":"Rui Sun, Bo Jin, Jinzhong Zhao, Xin Wu, Caixia Yuan","doi":"10.1002/cphc.202400882","DOIUrl":"https://doi.org/10.1002/cphc.202400882","url":null,"abstract":"<p><p>Delocalized multicenter bonds play a crucial role in clusters with a planar hypercoordinate center(s), making it difficult for highly electronegative elements, especially halogen atoms, to achieve the planar hypercoordinate arrangement. Herein, we introduce a star-like cluster Br6Li5-, whose global minimum contains a planar pentacoordinate bromine (ppBr). In this cluster, the central ppBr atom coordinates with five alkali metal Li atoms, which in turn bridge an equal number of electronegative Br atoms in the periphery, leading to the formation of the binary cluster Br6Li5-. Remarkably, bonding analyses indicate that the planar pentacoordinate configuration of Br6Li5- is dominated by the electrostatic interactions between the central ppBr atom and the Li5Br5 framework rather than covalent interactions. Despite the absence of delocalized bonds, Br6Li5- is still a highly stable cluster with a wider HOMO-LUMO gap of 7.73 eV and a higher VDE of 7.55 eV. Therefore, Br6Li5- should be a promising candidate for future gas-phase generation and spectroscopic characterization.</p>","PeriodicalId":9819,"journal":{"name":"Chemphyschem","volume":" ","pages":"e202400882"},"PeriodicalIF":2.3,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143037257","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":"α/β Conflicting Aromaticity Under the Microscope: Study of Pro-Aromatic Radicals.","authors":"Raúl Lago-Saavedra, Ignacio Pérez-Juste, Marcos Mandado","doi":"10.1002/cphc.202400529","DOIUrl":"10.1002/cphc.202400529","url":null,"abstract":"<p><p>The aromaticity of a representative sample of pro-aromatic radicals and its nitro, amino, hydroxyl and imine substituted derivatives has been analysed by means of multicenter delocalization indices (MCI) and nuclear-independent chemical shifts (NICS). Because of their radical character, these compounds may exhibit conflicting α/β aromaticity, so that the contribution of α and β electrons to the MCI and NICS has been analysed separately and their values qualitatively interpreted in terms of the 2n+1/2n rule. All the monocyclic radicals investigated show conflicting α/β aromaticity. Thus, significant MCI values have been found for one of the spin components, whereas negligible values, even slightly negative, have been obtained for the other spin component. NICS indices confirm the aromatic character reflected by the MCIs and clearly show the antiaromatic or non-aromatic character of the other spin components. The same has been found for the donor rings of the bicyclic pro-aromatic radicals investigated, whereas all the fused benzene rings of these radicals show a clear aromatic character in both spin components. Substitutions at the donor carbon position by strong deactivating groups provoke a small increase of the aromatic character in the aromatic spin components and a significant decrease of the antiaromatic character in the antiaromatic spin components whereas activating groups have little effect.</p>","PeriodicalId":9819,"journal":{"name":"Chemphyschem","volume":" ","pages":"e202400529"},"PeriodicalIF":2.3,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143032385","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}
ChemphyschemPub Date : 2025-01-22DOI: 10.1002/cphc.202401037
David Hernandez-Solarte, Leif Schröder
{"title":"RF Heating Effects in CEST NMR with Hyperpolarized <sup>129</sup>Xe Considering Different Spin Exchange Kinetics and Saturation Schemes.","authors":"David Hernandez-Solarte, Leif Schröder","doi":"10.1002/cphc.202401037","DOIUrl":"10.1002/cphc.202401037","url":null,"abstract":"<p><p>Chemical exchange saturation transfer (CEST) improves the sensitivity of NMR but depending on the spin exchange kinetics, it can require substantial RF energy deposition to label magnetization. Potential side effects like RF-induced heating may occur and must be monitored. Here, we explore the parameter space considering not only undesired heating but also efficient CEST build-up (depolarization rate), spectral resolution (line width), and subsequent effects like changes in chemical shifts of CEST responses. We present a systematic study to compare conventional block pulse with shaped-pulse saturation and quantify how the effective average saturation power impacts these parameters. Pulse shape and nominal excitation bandwidth, however, turned out to have little impact on acquired z-spectra and temperature changes. This study illustrates how different exchange kinetics define different regimes of suitable RF power within the dynamic range of fully saturable magnetization from hyperpolarized <sup>129</sup>Xe. Temperature-related changes in the resonance frequency of bound spins were also quantified for the two Xe hosts CB6 and CrA-ma and put into context for typically used CEST acquisition parameters, including the stability of the magnetic field.</p>","PeriodicalId":9819,"journal":{"name":"Chemphyschem","volume":" ","pages":"e202401037"},"PeriodicalIF":2.3,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143000967","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":"Dynamics of Pyrene Excimer in a Cholesteryl-Based Supramolecular Host Matrix.","authors":"Shubham Verma, Gargee Roy, Nikumoni Doley, Deepak Asthana, Sachin Dev Verma","doi":"10.1002/cphc.202400969","DOIUrl":"10.1002/cphc.202400969","url":null,"abstract":"<p><p>Aggregation-caused quenching (ACQ) reduces luminescence and compromises brightness in solid-state displays, necessitating strategies to mitigate its effects for enhanced performance. This study presents cost-effective method to mitigate ACQ of pyrene by co-assembling polycyclic aromatic hydrocarbons within low molecular weight gelator. Synthesized from readily available materials - cholesteryl chloroformate and pentaerythritol - in one-step reaction, gelator incorporates four cholesteryl units, reported to promote robust supramolecular gels in various solvents. Encapsulation of pyrene in a supramolecular host has effectively addressed the challenge of ACQ in the solid-state. Utilizing steady-state and time-resolved spectroscopic techniques, we probed the excimer formation dynamics across solution, powder, and xerogel phases. Through time-resolved emission spectra (TRES) and time-resolved area-normalized emission spectra (TRANES), we observed the monomer-to-excimer transition under various conditions. In solution, this transition occurs in a single step, characterized by a single isoemissive point (~443 nm) observed in TRANES. In powder, two isoemissive points (~445 nm and ~485 nm) were observed, indicating more complex process with an additional relaxed or trap state. The xerogel phase revealed an intricate excimer formation pathway, involving three isoemissive points (~418 nm, ~442 nm, and ~423 nm). These observations suggest multiple intermediate states in monomer-excimer transition and distinct dynamics in the solid matrix.</p>","PeriodicalId":9819,"journal":{"name":"Chemphyschem","volume":" ","pages":"e202400969"},"PeriodicalIF":2.3,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143000932","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}
ChemphyschemPub Date : 2025-01-20DOI: 10.1002/cphc.202580103
Taylor M. Currie, Jesse Davalos Barrios, Moc Lan Nguyen, Prof. Laurene Tetard, Prof. Titel Jurca
{"title":"Cover Feature: Foams-To-Films: A Facile Approach Towards Space-Confined CVD Growth of MoS2 (ChemPhysChem 1/2025)","authors":"Taylor M. Currie, Jesse Davalos Barrios, Moc Lan Nguyen, Prof. Laurene Tetard, Prof. Titel Jurca","doi":"10.1002/cphc.202580103","DOIUrl":"https://doi.org/10.1002/cphc.202580103","url":null,"abstract":"<p><b>The Cover Feature</b> shows the space-confined CVD growth of high-quality MoS<sub>2</sub> monolayers. The Research Article by T. Jurca and co-workers (DOI: 10.1002/cphc.202400854) describes the use of a nickel foam monolith preloaded with microstructured MoO<sub><i>x</i></sub> as the Mo source for the CVD process. By incorporation of a porous barrier and an inherently low loading of Mo source directly aligned with the substrate, this method ensures a dampened rate of delivery of both Mo and S to the substrate, leading to coverage of large, high-quality, mono-to-few layer triangular domains.\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure>\u0000 </p>","PeriodicalId":9819,"journal":{"name":"Chemphyschem","volume":"26 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cphc.202580103","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143117437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ChemphyschemPub Date : 2025-01-20DOI: 10.1002/cphc.202580101
Marta Porcaro, Miguel Sanz-Abad, Laura Michetti, Alessandro Conti, Caterina De Vito, María Teresa Doménech-Carbó, Antonio Doménech-Carbó
{"title":"Front Cover: Correlation Between Voltammetry of Immobilized Particles and Mott-Schottky Analysis of Metal Corrosion Patinas (ChemPhysChem 1/2025)","authors":"Marta Porcaro, Miguel Sanz-Abad, Laura Michetti, Alessandro Conti, Caterina De Vito, María Teresa Doménech-Carbó, Antonio Doménech-Carbó","doi":"10.1002/cphc.202580101","DOIUrl":"https://doi.org/10.1002/cphc.202580101","url":null,"abstract":"<p><b>The Front Cover</b> shows archaeological nails, which are used as substrates for combining Mott–Schottky and the voltammetry of immobilized particles in a study of metal corrosion. More information can be found in the Research Article by A. Doménech-Carbó and co-workers (DOI: 10.1002/cphc.202400805).\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure>\u0000 </p>","PeriodicalId":9819,"journal":{"name":"Chemphyschem","volume":"26 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cphc.202580101","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143117446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}