Chemistry methods : new approaches to solving problems in chemistry最新文献_第8页

Scanning Optical Spectroelectrochemistry: Applications in Protein Redox Potential Measurements 扫描光谱电化学：在蛋白质氧化还原电位测量中的应用

Chemistry methods : new approaches to solving problems in chemistry Pub Date : 2022-09-27 DOI: 10.1002/cmtd.202200047

Prof. Paul V. Bernhardt

{"title":"Scanning Optical Spectroelectrochemistry: Applications in Protein Redox Potential Measurements","authors":"Prof. Paul V. Bernhardt","doi":"10.1002/cmtd.202200047","DOIUrl":"10.1002/cmtd.202200047","url":null,"abstract":"The accurate measurement of redox potentials of small molecules is a relatively straightforward task using electrochemical methods such as cyclic voltammetry. However, proteins, in most cases, are not amenable to the same approach due to slow heterogeneous electron transfer and the possibility of denaturing at the electrode surface. This necessitates the use of small molecular weight redox mediators to facilitate electron transfer. This leads to spectroelectrochemical techniques where the applied electrochemical potential is coupled to a spectroscopic signal of the protein. Traditionally this is done at different applied (fixed) potentials akin to an electrochemical titration, but the time required for electrochemical equilibrium to be established, and its consistent application, are major sources of experimental error. Here we have utilised a continuously scanning potential synchronised with time-resolved UV-vis spectroscopy to provide an automated approach that can be used to measure protein redox potentials accurately in an expedient manner. The test cases are the heme proteins cytochrome c and myoglobin. The scope and limitations of the method are discussed.","PeriodicalId":72562,"journal":{"name":"Chemistry methods : new approaches to solving problems in chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cmtd.202200047","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49593982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

An Easy-to-Use Custom-Built Cell for Neutron Powder Diffraction Studies of Rechargeable Batteries 用于可充电电池中子粉末衍射研究的易于使用的定制电池

Chemistry methods : new approaches to solving problems in chemistry Pub Date : 2022-09-15 DOI: 10.1002/cmtd.202200046

Daniel Risskov Sørensen, Andreas Østergaard Drejer, Michael Heere, Anatoliy Senyshyn, Matthias Frontzek, Thomas Hansen, Christophe Didier, Vanessa K. Peterson, Dorthe Bomholdt Ravnsbæk, Mads Ry Vogel Jørgensen

{"title":"An Easy-to-Use Custom-Built Cell for Neutron Powder Diffraction Studies of Rechargeable Batteries","authors":"Daniel Risskov Sørensen, Andreas Østergaard Drejer, Michael Heere, Anatoliy Senyshyn, Matthias Frontzek, Thomas Hansen, Christophe Didier, Vanessa K. Peterson, Dorthe Bomholdt Ravnsbæk, Mads Ry Vogel Jørgensen","doi":"10.1002/cmtd.202200046","DOIUrl":"10.1002/cmtd.202200046","url":null,"abstract":"In operando powder diffraction remains one of the most powerful tools for non-destructive investigation of battery electrode materials. While in operando X-ray, especially synchrotron radiation, powder diffraction is by now a routine experimental technique, in operando neutron powder diffraction is still less established. We present a new electrochemical cell for in operando neutron powder diffraction, which is, first and foremost, easy to use, but can also cycle electrode materials under electrochemical conditions close to those achieved using standard laboratory cells. The cell has been designed in multiple sizes, and high-quality electrochemical and neutron powder diffraction data is presented for sample sizes as low as 48 mg total active material. The cell handles lithium-ion and sodium-ion materials equally well, with no difference in how the cell is prepared and assembled. The cell is intended to be used as sample environment at powder diffractometers at the neutron facilities MLZ, ORNL and ACNS.","PeriodicalId":72562,"journal":{"name":"Chemistry methods : new approaches to solving problems in chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://chemistry-europe.onlinelibrary.wiley.com/doi/epdf/10.1002/cmtd.202200046","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48659979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cover Picture: In Situ Studies of the Formation of Tungsten and Niobium Oxide Nanoparticles: Towards Automated Analysis of Reaction Pathways from PDF Analysis using the Pearson Correlation Coefficient (Chem. Methods 9/2022) 封面图片:钨和氧化铌纳米颗粒形成的原位研究:使用Pearson相关系数对PDF分析的反应途径进行自动分析。方法9/2022)

Chemistry methods : new approaches to solving problems in chemistry Pub Date : 2022-09-05 DOI: 10.1002/cmtd.202200053

Emil T. S. Kjær, Olivia Aalling-Frederiksen, Dr. Long Yang, Nancy K. Thomas, Dr. Mikkel Juelsholt, Prof. Simon J. L. Billinge, Dr. Kirsten M. Ø. Jensen

{"title":"Cover Picture: In Situ Studies of the Formation of Tungsten and Niobium Oxide Nanoparticles: Towards Automated Analysis of Reaction Pathways from PDF Analysis using the Pearson Correlation Coefficient (Chem. Methods 9/2022)","authors":"Emil T. S. Kjær, Olivia Aalling-Frederiksen, Dr. Long Yang, Nancy K. Thomas, Dr. Mikkel Juelsholt, Prof. Simon J. L. Billinge, Dr. Kirsten M. Ø. Jensen","doi":"10.1002/cmtd.202200053","DOIUrl":"10.1002/cmtd.202200053","url":null,"abstract":"The Front Cover shows a sketch of the formation process of metal oxide nanoparticles, where nanocrystalline oxides form from fragments of polyoxometalates. In situ X-ray total scattering studies with Pair Distribution Function analysis can give new insights into the formation process, as it provides structural information on all stages of the reaction – from precursor ions in solution, over amorphous or nanostructured intermediates to the final crystalline material. Here, we show how the analysis of such data can be automated using structure mining and simple computational tools. More information can be found in the Research Article by EmilT. S. Kjær0000et al..\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture>\u0000 </div>\u0000 </figure>\u0000 ","PeriodicalId":72562,"journal":{"name":"Chemistry methods : new approaches to solving problems in chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://chemistry-europe.onlinelibrary.wiley.com/doi/epdf/10.1002/cmtd.202200053","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45155910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

In Situ Studies of the Formation of Tungsten and Niobium Oxide Nanoparticles: Towards Automated Analysis of Reaction Pathways from PDF Analysis using the Pearson Correlation Coefficient 钨和氧化铌纳米颗粒形成的原位研究:利用Pearson相关系数对PDF分析的反应途径进行自动化分析

Chemistry methods : new approaches to solving problems in chemistry Pub Date : 2022-09-05 DOI: 10.1002/cmtd.202200052

Emil T. S. Kjær, Olivia Aalling-Frederiksen, Dr. Long Yang, Nancy K. Thomas, Dr. Mikkel Juelsholt, Prof. Simon J. L. Billinge, Dr. Kirsten M. Ø. Jensen

{"title":"In Situ Studies of the Formation of Tungsten and Niobium Oxide Nanoparticles: Towards Automated Analysis of Reaction Pathways from PDF Analysis using the Pearson Correlation Coefficient","authors":"Emil T. S. Kjær, Olivia Aalling-Frederiksen, Dr. Long Yang, Nancy K. Thomas, Dr. Mikkel Juelsholt, Prof. Simon J. L. Billinge, Dr. Kirsten M. Ø. Jensen","doi":"10.1002/cmtd.202200052","DOIUrl":"https://doi.org/10.1002/cmtd.202200052","url":null,"abstract":"Invited for this month's cover are the groups of Kirsten M. Ø. Jensen at the University of Copenhagen (Denmark) and Simon J. L. Billinge at Columbia University (US). The cover picture shows a sketch of the formation process of metal oxide nanoparticles, where nanocrystalline oxides form from fragments of e.g., polyoxometalates. In situ X-ray total scattering studies with Pair Distribution Function analysis can give new insights into the formation process, as it provides structural information on all stages of the reaction – from precursor ions in solution, over amorphous or nanostructured intermediates to the final crystalline material. Here, it is show how the analysis of such data can be automated using structure mining and simple computational tools. Read the full text of their Research Article at 10.1002/cmtd.202200034.","PeriodicalId":72562,"journal":{"name":"Chemistry methods : new approaches to solving problems in chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://chemistry-europe.onlinelibrary.wiley.com/doi/epdf/10.1002/cmtd.202200052","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91804347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Web Tool for Calculating Substituent Descriptors Compatible with Hammett Sigma Constants** 一个计算取代基描述符与哈米特σ常数兼容的网络工具**

Chemistry methods : new approaches to solving problems in chemistry Pub Date : 2022-08-30 DOI: 10.1002/cmtd.202200041

Dr. Peter Ertl

引用次数: 0

Quantification of the Strength of π-Noncovalent Interactions in Molecular Balances using Density Functional Methods 使用密度泛函方法量化分子平衡中π-非共价相互作用的强度

Chemistry methods : new approaches to solving problems in chemistry Pub Date : 2022-08-12 DOI: 10.1002/cmtd.202200044

Luka Nunar, Dr. Abil E. Aliev

{"title":"Quantification of the Strength of π-Noncovalent Interactions in Molecular Balances using Density Functional Methods","authors":"Luka Nunar, Dr. Abil E. Aliev","doi":"10.1002/cmtd.202200044","DOIUrl":"10.1002/cmtd.202200044","url":null,"abstract":"Different molecular balances were designed previously to compare noncovalent interactions. However, some balances are difficult to synthesise and there is a need for developing a computational approach. In this work, we probe noncovalent interactions of π systems using DFT methods to assess their reliability in reproducing experimentally measured conformer populations. Based on our results, the PW6B95D3 functional performed best, followed by M11L and ωB97XD. Additionally, the simulation of the rotation of the hydroxyl group revealed stabilising OH⋯Alkyne and OH⋯Nitrile interactions that are difficult to identify experimentally. These methods were then applied to compare the strengths of sulfur⋯π interactions in molecules which have not been explored experimentally. Compared to the hydroxyl counterpart, the simulation of the thiol group rotation showed that the geometry of the conformer with the two sulfur lone pairs oriented towards the aromatic ring or the double bond is stabilised, suggesting that S(LP)⋯π interactions can be attractive in nature. The ability of sulfur to rearrange its electronic surrounding to form an attractive interaction with π systems, including those with either electron-donating or withdrawing groups, was also confirmed. Overall, the results show a promising future for both qualitative and quantitative assessments of the strengths of noncovalent interactions using selected DFT techniques.","PeriodicalId":72562,"journal":{"name":"Chemistry methods : new approaches to solving problems in chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cmtd.202200044","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47125749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

In situ X-ray Scattering of the Crystallisation of Basic Magnesium Chlorides using a Laboratory Instrument 使用实验室仪器对碱性氯化镁结晶的原位X射线散射

Chemistry methods : new approaches to solving problems in chemistry Pub Date : 2022-08-09 DOI: 10.1002/cmtd.202200033

Katie S. Pickering, Dr. Steven Huband, Dr. Kirill L. Shafran, Prof. Richard I. Walton

{"title":"In situ X-ray Scattering of the Crystallisation of Basic Magnesium Chlorides using a Laboratory Instrument","authors":"Katie S. Pickering, Dr. Steven Huband, Dr. Kirill L. Shafran, Prof. Richard I. Walton","doi":"10.1002/cmtd.202200033","DOIUrl":"10.1002/cmtd.202200033","url":null,"abstract":"We demonstrate a method for in situ monitoring of the crystallisation of basic magnesium chlorides using a laboratory-based SAXS (small angle X-ray scattering)/ WAXS (wide angle X-ray scattering) instrument. By simultaneous acquisition of SAXS/WAXS, time-resolved particle size and phase evolution information was obtained from room temperature to 120 °C. The WAXS data were analysed using two-phase Rietveld refinements, to produce crystallisation curves. From Avrami-type kinetic analysis two competing mechanistic processes were proposed for the formation of Mg3Cl(OH)5 ⋅ 4 H2O with a nucleation-type mechanism extending further into the reaction with increased temperature. When comparing SAXS and WAXS, an offset between the consumption of MgO and the reduction of the sphere contribution to the SAXS scattering is observed. This is rationalised by the formation of an amorphous Mg(OH)2 layer on the MgO particle surface. Although laboratory-based SAXS/WAXS instruments have limitations compared to synchrotron-based sources, we have demonstrated how they can provide new insights into the formation of materials.","PeriodicalId":72562,"journal":{"name":"Chemistry methods : new approaches to solving problems in chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://chemistry-europe.onlinelibrary.wiley.com/doi/epdf/10.1002/cmtd.202200033","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42018283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Following Cu Microstructure Evolution in CuZnO/Al2O3(−Cs) Catalysts During Activation in H2 using in situ XRD and XRD-CT 用原位XRD和XRD‐CT研究CuZnO/ al2o3(−Cs)催化剂在h2活化过程中Cu的微观结构演变

Chemistry methods : new approaches to solving problems in chemistry Pub Date : 2022-08-03 DOI: 10.1002/cmtd.202200015

Dr. Daniela M. Farmer, Dr. Simon D. M. Jacques, Dr. David Waller, Dr. Sara Boullosa Eiras, Dr. Kanak Roy, Dr. Georg Held, Prof. Gopinathan Sankar, Prof. Andrew M. Beale

{"title":"Following Cu Microstructure Evolution in CuZnO/Al2O3(−Cs) Catalysts During Activation in H2 using in situ XRD and XRD-CT","authors":"Dr. Daniela M. Farmer, Dr. Simon D. M. Jacques, Dr. David Waller, Dr. Sara Boullosa Eiras, Dr. Kanak Roy, Dr. Georg Held, Prof. Gopinathan Sankar, Prof. Andrew M. Beale","doi":"10.1002/cmtd.202200015","DOIUrl":"10.1002/cmtd.202200015","url":null,"abstract":"Understanding how the microstructure of the active Cu0 component in the commercially applicable Cu/ZnO/Al2O3(−Cs2O) low-temperature water-gas shift catalyst evolves under various H2 partial pressures in the presence/absence of a Cs promoter during thermal activation has been investigated. Time-resolved XRD and spatially-resolved XRD-CT data were measured as a function of H2 concentration along a packed bed reactor to elucidate the importance of the zincite support and the effect of the promoter on Cu sintering mechanisms, dislocation character and stacking fault probability. The rate of Cu reduction showed a dependency on [Cs], [H2] and bed height; lower [Cs] and higher [H2] led to a greater rate of metallic copper nanoparticle formation. A deeper analysis of the XRD line profiles allowed for determining a greater edge character to the dislocations and subsequent stacking fault probability was also observed to depend on higher [H2], smaller Cu0 (and ZnO) crystallite sizes, increased [ZnO] (30 wt.%, sCZA) and lower temperature. The intrinsic activity of Cu/ZnO/Al2O3 methanol synthesis catalysts has been intimately linked to the anisotropic behaviour of copper, and thus the presence of lattice defects; to the best knowledge of the authors, this study is the first instance in which this type of analysis has been applied to LT-WGS catalysts.","PeriodicalId":72562,"journal":{"name":"Chemistry methods : new approaches to solving problems in chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cmtd.202200015","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43677571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

In Situ Studies of the Formation of Tungsten and Niobium Oxide Nanoparticles: Towards Automated Analysis of Reaction Pathways from PDF Analysis using the Pearson Correlation Coefficient 在里面钨和氧化铌纳米颗粒形成的原位研究：利用Pearson相关系数从PDF分析中自动分析反应途径

Chemistry methods : new approaches to solving problems in chemistry Pub Date : 2022-08-03 DOI: 10.1002/cmtd.202200034

Emil T. S. Kjær, Olivia Aalling-Frederiksen, Dr. Long Yang, Nancy K. Thomas, Dr. Mikkel Juelsholt, Prof. Simon J. L. Billinge, Dr. Kirsten M. Ø. Jensen

{"title":"In Situ Studies of the Formation of Tungsten and Niobium Oxide Nanoparticles: Towards Automated Analysis of Reaction Pathways from PDF Analysis using the Pearson Correlation Coefficient","authors":"Emil T. S. Kjær, Olivia Aalling-Frederiksen, Dr. Long Yang, Nancy K. Thomas, Dr. Mikkel Juelsholt, Prof. Simon J. L. Billinge, Dr. Kirsten M. Ø. Jensen","doi":"10.1002/cmtd.202200034","DOIUrl":"10.1002/cmtd.202200034","url":null,"abstract":"Using Pair Distribution Function (PDF) analysis of in situ total scattering data, we investigate the formation of tungsten and niobium oxides in a simple solvothermal synthesis. We use Pearson Correlation Coefficient (PCC) analysis of the time resolved PDFs to both map the structural changes taking place throughout the synthesis and identify structural models for precursor and product through PCC-based structure mining. Our analysis first shows that ultra-small tungsten and niobium oxide nanoparticles form instantaneously upon heating, with sizes between 1.5 and 2 nm. We show that the main structural motifs in the nanoparticles can be described with structures containing pentagonal columns, which is characteristic for many bulk tungsten and niobium oxides. We furthermore elucidate the structure of the precursor complex as clusters of octahedra with O- and Cl-ligands. The PCC based methodology automates the structure characterization and proves useful for analysis of large datasets of for example, time resolved X-ray scattering studies. The PCC is implemented in ‘PDF in the cloud’, a web platform for PDF analysis.","PeriodicalId":72562,"journal":{"name":"Chemistry methods : new approaches to solving problems in chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://chemistry-europe.onlinelibrary.wiley.com/doi/epdf/10.1002/cmtd.202200034","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49251621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Cover Picture: Flow Synthesis of Single and Mixed Metal Oxides (Chem. Methods 8/2022) 封面图片:单一和混合金属氧化物的流动合成(化学)。方法8/2022)

Chemistry methods : new approaches to solving problems in chemistry Pub Date : 2022-07-25 DOI: 10.1002/cmtd.202200048

Dr. Zachary S. Campbell, Steven Baro, Dr. Yunfei Gao, Prof. Fanxing Li, Prof. Milad Abolhasani

引用次数: 0