Anthony West, Yangyang Roy Zhao, Laurence Roy Middlemiss, Xuan Roy Zhi, Peter Roy Gross
It is widely recognised that oxygen redox makes a significant contribution to the high capacity of some cathode materials in addition to transition metal redox. We attribute this to the presence of underbonded oxide ions, either in bulk structures or at surfaces, which are the initial source of oxygen redox during charging. Underbonded oxide ions experience departures from local electroneutrality; examples include Li4Mn5O12 spinel and Li‐rich layered rock salt structures but not stoichiometric LiCoO2 or Li2MnO3. Underbonded oxide ions ionise more readily than fully‐stabilised lattice oxide ions since, using an ionic bonding description, they are associated with a deficiency of positive charge in the coordination sphere of surrounding cations. Pauling’s electrostatic bond strength criterion gives a simple guide to structures or compositions that show departures from local electroneutrality and provides the starting point for a new way to consider oxygen redox. Li4Mn5O12 behaves as an anode due to Mn redox below 3V and as a cathode due to reversible oxygen redox above ~3.8 V. Underbonded oxygens are also identified in other structures, including high capacity Li‐rich layered rock salt structures.
{"title":"Oxygen redox activity in battery cathodes and the role of underbonded oxygen","authors":"Anthony West, Yangyang Roy Zhao, Laurence Roy Middlemiss, Xuan Roy Zhi, Peter Roy Gross","doi":"10.1002/zaac.202400067","DOIUrl":"https://doi.org/10.1002/zaac.202400067","url":null,"abstract":"It is widely recognised that oxygen redox makes a significant contribution to the high capacity of some cathode materials in addition to transition metal redox. We attribute this to the presence of underbonded oxide ions, either in bulk structures or at surfaces, which are the initial source of oxygen redox during charging. Underbonded oxide ions experience departures from local electroneutrality; examples include Li4Mn5O12 spinel and Li‐rich layered rock salt structures but not stoichiometric LiCoO2 or Li2MnO3. Underbonded oxide ions ionise more readily than fully‐stabilised lattice oxide ions since, using an ionic bonding description, they are associated with a deficiency of positive charge in the coordination sphere of surrounding cations. Pauling’s electrostatic bond strength criterion gives a simple guide to structures or compositions that show departures from local electroneutrality and provides the starting point for a new way to consider oxygen redox. Li4Mn5O12 behaves as an anode due to Mn redox below 3V and as a cathode due to reversible oxygen redox above ~3.8 V. Underbonded oxygens are also identified in other structures, including high capacity Li‐rich layered rock salt structures.","PeriodicalId":23934,"journal":{"name":"Zeitschrift für anorganische und allgemeine Chemie","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142249060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The novel inoborate Ni[B2O2(OH)4] was synthesized under high‐pressure/high‐temperature conditions of 9 GPa and 800 °C. Its structure was determined via single‐crystal X‐ray diffraction analysis. The single‐grain IR‐spectrum of Ni[B2O2(OH)4] supports the existence of O–H bonds. The structural similarities and differences with the mineral vimsite possessing the sum formula Ca[B2O2(OH)4], as well as with the phylloborate HP‐Ni(B2O4) is discussed. The title compound can be described as the structural hydrolysis product of the latter.
新型铌酸镍[B2O2(OH)4]是在 9 GPa 和 800 °C 的高压/高温条件下合成的。通过单晶 X 射线衍射分析确定了其结构。镍[B2O2(OH)4]的单晶红外光谱证明了 O-H 键的存在。本文讨论了该化合物与总式为 Ca[B2O2(OH)4] 的矿物 vimsite 以及栅硼酸盐 HP-Ni(B2O4) 在结构上的异同。标题化合物可以说是后者的结构水解产物。
{"title":"High‐Pressure Synthesis and Crystal Structure of the Inoborate Ni[B2O2(OH)4]","authors":"Leonard Conrad Pasqualini, Hubert Huppertz","doi":"10.1002/zaac.202400137","DOIUrl":"https://doi.org/10.1002/zaac.202400137","url":null,"abstract":"The novel inoborate Ni[B2O2(OH)4] was synthesized under high‐pressure/high‐temperature conditions of 9 GPa and 800 °C. Its structure was determined via single‐crystal X‐ray diffraction analysis. The single‐grain IR‐spectrum of Ni[B2O2(OH)4] supports the existence of O–H bonds. The structural similarities and differences with the mineral vimsite possessing the sum formula Ca[B2O2(OH)4], as well as with the phylloborate HP‐Ni(B2O4) is discussed. The title compound can be described as the structural hydrolysis product of the latter.","PeriodicalId":23934,"journal":{"name":"Zeitschrift für anorganische und allgemeine Chemie","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The extraction of the solid state materials “MSnBix“ (M/x=Cs/1, Na/3) in liquid ammonia in the presence of different chelating agents yielded the novel Zintl anion [Sn5Bi3]3−. The anion could be crystallized and characterized via single crystal X‐ray diffraction in [Cs@[18]crown‐6]3[Sn5Bi3] ⋅ 7NH3, [K@[18]crown‐6]1.5[Cs@[18]crown‐6][Cs@([18]crown‐6)2]0.5[Sn5Bi3] ⋅ 3.98NH3, [Na@DB[18]crown‐6]2[Na(NH3)6][Sn5Bi3] ⋅ 14NH3 and [Cs@[2.2.2]crypt]6[Sn5Bi3]2 ⋅ 9.53NH3. The [Sn5Bi3]3− anion is further investigated by mass spectrometry and DFT calculations to confirm its composition and elucidate its electronic structure.
固态材料 "MSnBix"（M/x=Cs/1，Na/3）在不同螯合剂存在下于液氨中萃取，得到了新型 Zintl 阴离子[Sn5Bi3]3-。该阴离子可以结晶，并通过单晶 X 射线衍射在[Cs@[18]crown-6]3[Sn5Bi3]⋅7NH3、[K@[18]crown-6]1.5[Cs@[18]crown-6][Cs@([18]crown-6)2]0.5[Sn5Bi3]⋅3.98NH3，[Na@DB[18]crown-6]2[Na(NH3)6][Sn5Bi3]⋅14NH3 和 [Cs@[2.2.2]crypt]6[Sn5Bi3]2⋅9.53NH3。质谱法和 DFT 计算进一步研究了[Sn5Bi3]3-阴离子，以确认其组成并阐明其电子结构。
{"title":"Synthesis and Single Crystal X‐ray Characterization of [Sn5Bi3]3−","authors":"Ute Friedrich, Franz Schmidt, Nikolaus Korber","doi":"10.1002/zaac.202400086","DOIUrl":"https://doi.org/10.1002/zaac.202400086","url":null,"abstract":"The extraction of the solid state materials <jats:italic>“M</jats:italic>SnBi<jats:sub><jats:italic>x</jats:italic></jats:sub><jats:italic>“</jats:italic> (<jats:italic>M</jats:italic>/<jats:italic>x</jats:italic>=Cs/1, Na/3) in liquid ammonia in the presence of different chelating agents yielded the novel Zintl anion [Sn<jats:sub>5</jats:sub>Bi<jats:sub>3</jats:sub>]<jats:sup>3−</jats:sup>. The anion could be crystallized and characterized via single crystal X‐ray diffraction in [Cs@[18]crown‐6]<jats:sub>3</jats:sub>[Sn<jats:sub>5</jats:sub>Bi<jats:sub>3</jats:sub>] ⋅ 7NH<jats:sub>3</jats:sub>, [K@[18]crown‐6]<jats:sub>1.5</jats:sub>[Cs@[18]crown‐6][Cs@([18]crown‐6)<jats:sub>2</jats:sub>]<jats:sub>0.5</jats:sub>[Sn<jats:sub>5</jats:sub>Bi<jats:sub>3</jats:sub>] ⋅ 3.98NH<jats:sub>3</jats:sub>, [Na@DB[18]crown‐6]<jats:sub>2</jats:sub>[Na(NH<jats:sub>3</jats:sub>)<jats:sub>6</jats:sub>][Sn<jats:sub>5</jats:sub>Bi<jats:sub>3</jats:sub>] ⋅ 14NH<jats:sub>3</jats:sub> and [Cs@[2.2.2]crypt]<jats:sub>6</jats:sub>[Sn<jats:sub>5</jats:sub>Bi<jats:sub>3</jats:sub>]<jats:sub>2</jats:sub> ⋅ 9.53NH<jats:sub>3</jats:sub>. The [Sn<jats:sub>5</jats:sub>Bi<jats:sub>3</jats:sub>]<jats:sup>3−</jats:sup> anion is further investigated by mass spectrometry and DFT calculations to confirm its composition and elucidate its electronic structure.","PeriodicalId":23934,"journal":{"name":"Zeitschrift für anorganische und allgemeine Chemie","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A pair of enantiomerically chiral dysprosium homodinuclear complexes: [(acac)4Dy2(R,R,R,R‐L)] (R‐Dy) and [(acac)4Dy2(S,S,S,S‐L)] (S‐Dy) (Hacac = acetylacetone) have been synthesized based on macrocyclic chiral ligands (R,R,R,R‐H2L/S,S,S,S‐H2L), derived from the [2+2] template condensation of 4‐tert‐butyl‐2,6‐diformylphenol, dysprosium acetylacetonate and (1R,2R)‐/(1S,2S)‐1,2‐cyclohexanediamine, respectively. Circular dichroism spectra confirms their enantiomeric chirality. Single‐crystal structures show two crystallographic independent dysprosium(III) ions have square antiprismatic coordination with different D4d local symmetry. Furthermore, the selected R‐Dy complex owns the slow magnetic relaxation behaviour with the ferromagnetic Dy3+···Dy3+ coupling.
{"title":"Chiral Homodinuclear Dysprosium Macrocyclic Complexes with Single‐molecule Magnetic Behaviours","authors":"Zi-Hang Cheng, Ru-Chan Liu, Feng Gao","doi":"10.1002/zaac.202400139","DOIUrl":"https://doi.org/10.1002/zaac.202400139","url":null,"abstract":"A pair of enantiomerically chiral dysprosium homodinuclear complexes: [(acac)4Dy2(R,R,R,R‐L)] (R‐Dy) and [(acac)4Dy2(S,S,S,S‐L)] (S‐Dy) (Hacac = acetylacetone) have been synthesized based on macrocyclic chiral ligands (R,R,R,R‐H2L/S,S,S,S‐H2L), derived from the [2+2] template condensation of 4‐tert‐butyl‐2,6‐diformylphenol, dysprosium acetylacetonate and (1R,2R)‐/(1S,2S)‐1,2‐cyclohexanediamine, respectively. Circular dichroism spectra confirms their enantiomeric chirality. Single‐crystal structures show two crystallographic independent dysprosium(III) ions have square antiprismatic coordination with different D4d local symmetry. Furthermore, the selected R‐Dy complex owns the slow magnetic relaxation behaviour with the ferromagnetic Dy3+···Dy3+ coupling.","PeriodicalId":23934,"journal":{"name":"Zeitschrift für anorganische und allgemeine Chemie","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A highly selective approach with high yields of two diastereomeric silicon‐stereogenic menthoxysilanes, (RSi)‐3 and (SSi)‐3, introduced by Sommer et al., could be established as well as investigated in detail using different analytical tools. Single‐crystal X‐ray diffraction analysis was used to examine the different crystallization rates while Hirshfeld surface analysis was applied to extend supramolecular interactions in the solid state which showed stronger hydrogen bridges for the faster crystallizing diastereomer (SSi)‐3. In addition, similar ground‐state energies have been found for both diastereomers by DFT calculations. Subsequent NMR studies showed stable Si‐configurations wherein epimerization only started after more than 4 hours at 110 °C. Access to both diastereomers with opposite configuration at the stereogenic silicon center is achievable in high yields and high stereochemical purity using only naturally occurring (–)‐menthol as a reagent.
通过使用不同的分析工具对 Sommer 等人提出的两种非对映生硅薄荷硅烷--(RSi)-3 和 (SSi)-3 进行详细研究，建立了一种高产率的高选择性方法。单晶 X 射线衍射分析用于研究不同的结晶速度，而 Hirshfeld 表面分析则用于扩展固态超分子相互作用，结果表明结晶速度更快的非对映异构体 (SSi)-3 具有更强的氢桥。此外，通过 DFT 计算还发现两种非对映异构体的基态能量相似。随后的核磁共振研究显示，Si-构型稳定，在 110 °C 下超过 4 小时后才开始发生外延。只需使用天然存在的 (-)- 薄荷醇作为试剂，就能以高产率和高立体化学纯度获得立体硅中心构型相反的两种非对映异构体。
{"title":"Supramolecular Interactions as Key in Racemic Resolution: New Insights into the (SSi)‐ and (RSi)‐Diastereomers of (1R,2S,5R)‐Methyl(1‐naphthyl)‐phenylmenthoxysilane of Sommer","authors":"Jan-Lukas Kirchhoff, Carsten Strohmann","doi":"10.1002/zaac.202400135","DOIUrl":"https://doi.org/10.1002/zaac.202400135","url":null,"abstract":"A highly selective approach with high yields of two diastereomeric silicon‐stereogenic menthoxysilanes, (RSi)‐3 and (SSi)‐3, introduced by Sommer et al., could be established as well as investigated in detail using different analytical tools. Single‐crystal X‐ray diffraction analysis was used to examine the different crystallization rates while Hirshfeld surface analysis was applied to extend supramolecular interactions in the solid state which showed stronger hydrogen bridges for the faster crystallizing diastereomer (SSi)‐3. In addition, similar ground‐state energies have been found for both diastereomers by DFT calculations. Subsequent NMR studies showed stable Si‐configurations wherein epimerization only started after more than 4 hours at 110 °C. Access to both diastereomers with opposite configuration at the stereogenic silicon center is achievable in high yields and high stereochemical purity using only naturally occurring (–)‐menthol as a reagent.","PeriodicalId":23934,"journal":{"name":"Zeitschrift für anorganische und allgemeine Chemie","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hans Reuter, Simona Schröder, Natalie Röwekamp-Krugley, Markus Imwalle
In order to study the formation of complexes independently from stoichiometry we developed a microscale experiment that allows us to monitor the reaction progress by light microscopy In the present study, the complex formation between SnF2 and 1,10‐phenanthroline (phen) with N,N‐dimethylformamide as solvent was investigated over a period of some weeks. By use of this setup, the formation of three different crystals has been observed, whose compositions and structures were determined by single crystal X‐ray diffraction: 3SnF2 · phen, 1, 2SnF2 · SnF4 · phen, 2, SnF4 · phen, 3. While the octahedral fluorine environment of the tin(IV) atoms of 2 and 3 is very regular, the coordinations of the tin(II) atoms in 1 and 2 is irregular. Assuming a non‐bonding 5s electron pair, classical 2c‐2e‐ and symmetrical and asymmetrical, hypervalent 3c‐4e‐bonds ‐ all based on the orthogonal p atomic orbitals of Sn – an approach to analyse and describe these coordinations in a simple comprehensive way is presented.
为了研究络合物的形成而不受化学计量学的影响，我们开发了一种微尺度实验，使我们能够通过光学显微镜监测反应的进展。通过使用这种装置，观察到了三种不同晶体的形成，并通过单晶 X 射线衍射确定了它们的成分和结构：2 和 3 中锡（IV）原子的八面体氟环境非常规则，而 1 和 2 中锡（II）原子的配位则不规则。假定存在非成键的 5s 电子对、经典的 2c-2e-、对称和不对称的高价 3c-4e-键--所有这些都基于锡的正交 p 原子轨道--本文提出了一种以简单全面的方式分析和描述这些配位的方法。
{"title":"From tin(II) to tin(IV): Following solid‐liquid reactions by microscopy","authors":"Hans Reuter, Simona Schröder, Natalie Röwekamp-Krugley, Markus Imwalle","doi":"10.1002/zaac.202400091","DOIUrl":"https://doi.org/10.1002/zaac.202400091","url":null,"abstract":"In order to study the formation of complexes independently from stoichiometry we developed a microscale experiment that allows us to monitor the reaction progress by light microscopy In the present study, the complex formation between SnF2 and 1,10‐phenanthroline (phen) with N,N‐dimethylformamide as solvent was investigated over a period of some weeks. By use of this setup, the formation of three different crystals has been observed, whose compositions and structures were determined by single crystal X‐ray diffraction: 3SnF2 · phen, 1, 2SnF2 · SnF4 · phen, 2, SnF4 · phen, 3. While the octahedral fluorine environment of the tin(IV) atoms of 2 and 3 is very regular, the coordinations of the tin(II) atoms in 1 and 2 is irregular. Assuming a non‐bonding 5s electron pair, classical 2c‐2e‐ and symmetrical and asymmetrical, hypervalent 3c‐4e‐bonds ‐ all based on the orthogonal p atomic orbitals of Sn – an approach to analyse and describe these coordinations in a simple comprehensive way is presented.","PeriodicalId":23934,"journal":{"name":"Zeitschrift für anorganische und allgemeine Chemie","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bin Liu, Liang He, Zi-chen Shi, Wen-hui Huang, Qi Xue, Jian-hui Yang
Sodium salt of 1,3‐bis(5‐tetrazolyl)triazene (NaH2BTT‧4H2O) was obtained through diazo‐couple reaction with 5‐aminotetrazole as starting reactants, and a family of energetic ionic crystals of the 1,3‐bis(5‐tetrazolyl)triazene anions HnBTT(3‐n)‐ with different cations were investigated, including protonated amines (ethanediamine, hydrazinium, aminoguanidine, methylhydrazinium) and Y(H2O)83+. The structures and physicochemical properties of these compounds were characterized by IR, Raman, X‐ray diffraction (XRPD) and TG‐DSC. Ethanediamine salt is the best thermal stable, while hydrazinium salt possess a highest nitrogen rich value of 79.76%. Both of them show a rapid collapse of the BTT main frame, and almost all of the dissociation products are released in the form of gas.
{"title":"Syntheses, structures, properties, and calculation of a family of ionic crystals based on 1,3‐bis(5‐tetrazolyl)triazene","authors":"Bin Liu, Liang He, Zi-chen Shi, Wen-hui Huang, Qi Xue, Jian-hui Yang","doi":"10.1002/zaac.202400049","DOIUrl":"https://doi.org/10.1002/zaac.202400049","url":null,"abstract":"Sodium salt of 1,3‐bis(5‐tetrazolyl)triazene (NaH2BTT‧4H2O) was obtained through diazo‐couple reaction with 5‐aminotetrazole as starting reactants, and a family of energetic ionic crystals of the 1,3‐bis(5‐tetrazolyl)triazene anions HnBTT(3‐n)‐ with different cations were investigated, including protonated amines (ethanediamine, hydrazinium, aminoguanidine, methylhydrazinium) and Y(H2O)83+. The structures and physicochemical properties of these compounds were characterized by IR, Raman, X‐ray diffraction (XRPD) and TG‐DSC. Ethanediamine salt is the best thermal stable, while hydrazinium salt possess a highest nitrogen rich value of 79.76%. Both of them show a rapid collapse of the BTT main frame, and almost all of the dissociation products are released in the form of gas.","PeriodicalId":23934,"journal":{"name":"Zeitschrift für anorganische und allgemeine Chemie","volume":"114 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dejan Zagorac, Jelena Zagorac, Tamara Škundrić, Milan Pejić, Dušica Jovanović, J. Christian Schön
Tantalum carbide (TaC) is an extremely hard, brittle, refractory ceramic material with excellent physical properties, which makes it a desirable material in e.g. aerospace industries. In order to explore the range of feasible modifications of TaC, we have executed a crystal structure prediction study of the TaC chemical system using a multi‐methodological approach, via enthalpy landscape explorations of pristine TaC at different pressures, supplemented by data mining searches in the ICSD database. Local structure relaxations have been accomplished by using Density Functional Theory (DFT). The global minimum is found to correspond to the equilibrium rock salt (NaCl) type modification. Additionally, eight new phases of tantalum carbide are predicted to be feasible: the WC‐type, the NiAs‐type, the 5‐5‐type, the ZnS‐type, the Ring_TaC‐type, the CsCl‐type, the Ortho_TaC‐type, and the Tetra_TaC‐type. Furthermore, the elastic and mechanical properties of the predicted TaC modifications were explored on the DFT level of computation. The promising values of some of the mechanical properties of the proposed tantalum carbide modifications suggest that various scientific, industrial and technological applications of TaC should be possible.
{"title":"Structure prediction and mechanical properties of tantalum carbide (TaC) on ab initio level","authors":"Dejan Zagorac, Jelena Zagorac, Tamara Škundrić, Milan Pejić, Dušica Jovanović, J. Christian Schön","doi":"10.1002/zaac.202400088","DOIUrl":"https://doi.org/10.1002/zaac.202400088","url":null,"abstract":"Tantalum carbide (TaC) is an extremely hard, brittle, refractory ceramic material with excellent physical properties, which makes it a desirable material in e.g. aerospace industries. In order to explore the range of feasible modifications of TaC, we have executed a crystal structure prediction study of the TaC chemical system using a multi‐methodological approach, via enthalpy landscape explorations of pristine TaC at different pressures, supplemented by data mining searches in the ICSD database. Local structure relaxations have been accomplished by using Density Functional Theory (DFT). The global minimum is found to correspond to the equilibrium rock salt (NaCl) type modification. Additionally, eight new phases of tantalum carbide are predicted to be feasible: the WC‐type, the NiAs‐type, the 5‐5‐type, the ZnS‐type, the Ring_TaC‐type, the CsCl‐type, the Ortho_TaC‐type, and the Tetra_TaC‐type. Furthermore, the elastic and mechanical properties of the predicted TaC modifications were explored on the DFT level of computation. The promising values of some of the mechanical properties of the proposed tantalum carbide modifications suggest that various scientific, industrial and technological applications of TaC should be possible.","PeriodicalId":23934,"journal":{"name":"Zeitschrift für anorganische und allgemeine Chemie","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dharma Teja Teppala, Jan Bernauer, Esteve Drouillard, Yaswanth Kumar Geddam, Guoxing Chen, Marc Widenmeyer, Maximilian Trapp, Hans-Joachim Kleebe, Ravi Kumar, Sanjay Mathur, Emanuel Ionescu
In the current work, a simple mechanochemical route has been employed to preparatively access three spinel‐type compositionally complex ceramics, i.e., (Co, Fe, Mn)3O4, (Co, Fe, Mn, Ni)3O4, and (Co, Cr, Fe, Mn, Ni)3O4. Hydrated nitrate salts of the respective transition metal elements were mechanically ground with ammonium hydrogen carbonate. The resulting paste‐like mixture of metal hydroxides, oxyhydroxides, and carbonates was rinsed with water to remove the byproduct (NH4NO3) and converted into the respective single‐phase spinel‐type oxides via calcination. In situ X‐ray diffraction (XRD) revealed the formation of the spinel‐type structure (Fdm) already at temperatures as low as 150 °C. Typically, the calcination of the precursors at temperatures beyond 500 °C led to the formation of well‐crystallized, single‐phase spinel‐type oxides with nearly equimolar composition and highly homogeneous distribution of the transition metals within the structure. The mechanochemical synthesis route in the present study is considered to be an easy, straightforward, and scalable access to compositionally complex oxides.
在目前的研究工作中，采用了一种简单的机械化学方法来制备三种尖晶石型成分复杂的陶瓷，即（Co、Fe、Mn）3O4、（Co、Fe、Mn、Ni）3O4 和（Co、Cr、Fe、Mn、Ni）3O4。各过渡金属元素的水合硝酸盐用碳酸氢铵进行机械研磨。用水冲洗金属氢氧化物、氧氢氧化物和碳酸盐的糊状混合物以除去副产品（NH4NO3），然后通过煅烧将其转化为相应的单相尖晶石型氧化物。原位 X 射线衍射（XRD）显示，尖晶石型结构（Fdm）在低至 150 °C 的温度下就已形成。通常情况下，前驱体的煅烧温度超过 500 °C，就会形成结晶良好的单相尖晶石型氧化物，其成分接近等摩尔，过渡金属在结构中的分布高度均匀。本研究中的机械化学合成路线被认为是获得成分复杂的氧化物的一种简单、直接和可扩展的途径。
{"title":"Facile mechanochemical synthesis of compositionally complex spinel‐type oxides, (Co, Fe, Mn)3O4, (Co, Fe, Mn, Ni)3O4, (Co, Cr, Fe, Mn, Ni)3O4","authors":"Dharma Teja Teppala, Jan Bernauer, Esteve Drouillard, Yaswanth Kumar Geddam, Guoxing Chen, Marc Widenmeyer, Maximilian Trapp, Hans-Joachim Kleebe, Ravi Kumar, Sanjay Mathur, Emanuel Ionescu","doi":"10.1002/zaac.202400134","DOIUrl":"https://doi.org/10.1002/zaac.202400134","url":null,"abstract":"In the current work, a simple mechanochemical route has been employed to preparatively access three spinel‐type compositionally complex ceramics, i.e., (Co, Fe, Mn)3O4, (Co, Fe, Mn, Ni)3O4, and (Co, Cr, Fe, Mn, Ni)3O4. Hydrated nitrate salts of the respective transition metal elements were mechanically ground with ammonium hydrogen carbonate. The resulting paste‐like mixture of metal hydroxides, oxyhydroxides, and carbonates was rinsed with water to remove the byproduct (NH4NO3) and converted into the respective single‐phase spinel‐type oxides via calcination. In situ X‐ray diffraction (XRD) revealed the formation of the spinel‐type structure (Fdm) already at temperatures as low as 150 °C. Typically, the calcination of the precursors at temperatures beyond 500 °C led to the formation of well‐crystallized, single‐phase spinel‐type oxides with nearly equimolar composition and highly homogeneous distribution of the transition metals within the structure. The mechanochemical synthesis route in the present study is considered to be an easy, straightforward, and scalable access to compositionally complex oxides.","PeriodicalId":23934,"journal":{"name":"Zeitschrift für anorganische und allgemeine Chemie","volume":"74 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Johannes Beck, Thomas Bredow, Jörg Daniels, Marcus Zink, Doris Ernsthäuser, Dominik Thönnes
The reactions of a series of organic polynitriles with [Te4][AsF6]2 in liquid SO2 solution lead either to reduction of [Te4]2+ to elemental tellurium or to the formation of coordination polymers. With 1,3‐dicyanobenzene (1,3‐DCB), 1,4‐dicyanobenzene (1,4‐DCB), 1,2,4,5‐tetracyanobenzene (TCB), tetracyanoethylene (TCNE) and tetracyanochinodimethane (TCNQ) the coordination complexes [Te4][AsF6]2 · 2(1,3‐DCB), [Te4][AsF6]2 · 3(1,4‐DCB) · 2SO2, [Te4][AsF6]2 · TCB, [Te4][AsF6]2 · TCNE and [Te4][AsF6]2 · TCNQ · 8SO2 were isolated and characterized by crystal structure analyses and vibrational Raman spectroscopy. The nitriles are coordinated to the square‐planar clusters forming 1D chains, 2D arrangements and 3D networks. Tetrakis(dicyanomethylene)‐cyclobutendiide [C4(C{CN}2)4]2‒ is oxidized by [Te4]2+ to the neutral cyanocarbon C4(C{CN}2)4 structurally representing a 4[radialene]. The ionization potentials and electron affinities of the cyanamide anion, cyanogen, 1,2‐DCB, 1,3‐DCB, 1,4‐DCB, TCB, C4(C{CN}2)4, TCNE and TCNQ and those polynitriles, which cause reduction of [Te4]2+, were calculated at coupled‐cluster level of theory in order to examine possible reasons for the stability of the coordination polymers based on electronic properties of the nitriles.
{"title":"Coordination Networks from [Te4]2+ Clusters and Polynitriles","authors":"Johannes Beck, Thomas Bredow, Jörg Daniels, Marcus Zink, Doris Ernsthäuser, Dominik Thönnes","doi":"10.1002/zaac.202400112","DOIUrl":"https://doi.org/10.1002/zaac.202400112","url":null,"abstract":"The reactions of a series of organic polynitriles with [Te4][AsF6]2 in liquid SO2 solution lead either to reduction of [Te4]2+ to elemental tellurium or to the formation of coordination polymers. With 1,3‐dicyanobenzene (1,3‐DCB), 1,4‐dicyanobenzene (1,4‐DCB), 1,2,4,5‐tetracyanobenzene (TCB), tetracyanoethylene (TCNE) and tetracyanochinodimethane (TCNQ) the coordination complexes [Te4][AsF6]2 · 2(1,3‐DCB), [Te4][AsF6]2 · 3(1,4‐DCB) · 2SO2, [Te4][AsF6]2 · TCB, [Te4][AsF6]2 · TCNE and [Te4][AsF6]2 · TCNQ · 8SO2 were isolated and characterized by crystal structure analyses and vibrational Raman spectroscopy. The nitriles are coordinated to the square‐planar clusters forming 1D chains, 2D arrangements and 3D networks. Tetrakis(dicyanomethylene)‐cyclobutendiide [C4(C{CN}2)4]2‒ is oxidized by [Te4]2+ to the neutral cyanocarbon C4(C{CN}2)4 structurally representing a 4[radialene]. The ionization potentials and electron affinities of the cyanamide anion, cyanogen, 1,2‐DCB, 1,3‐DCB, 1,4‐DCB, TCB, C4(C{CN}2)4, TCNE and TCNQ and those polynitriles, which cause reduction of [Te4]2+, were calculated at coupled‐cluster level of theory in order to examine possible reasons for the stability of the coordination polymers based on electronic properties of the nitriles.","PeriodicalId":23934,"journal":{"name":"Zeitschrift für anorganische und allgemeine Chemie","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：