Alkali chalkogenido metalates(II/III)

碱金属硫族金属酸盐(II/III)

• 批准号: 313431712
• 负责人: Professorin Dr.-Ing. Caroline Röhr
• 金额: --
• 依托单位: Lehrstuhl für Festkörperchemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/313431712?language=en
• 关键词: Alkali; chalkogenido; metalates; II; III

Alkali metal (A) salts of mixed-valent chalcogenido(Q) ferrate(II/III) anions (A=Na, K, Rb Cs; Q=S, Se, Te) are a structurally variable class of compounds, which are furthermore models for much complexer systems like e.g. redox enzymes or iron-based superconductors.Their crystal chemistry, which has been recentyl extended by many mixed-valent Fe-rich salts (mainly via using reductive synthetic strategies) is based on edge-sharing [FeQ4] tetrahedra. Particularly diverse are the tetrahedra connections and the anions/crystal structures along the section A[FeQ2]-A2[FeQ2]: At one hand, chains of edge-sharing tetrahedra in several conformations, which depend on the Fe(II):Fe(III) ratio and the A cations, are found. On the other hand [exclusively in mixed-valent ferrates] 4Fe4S analog tetrahedra clusters [Fe4Q8] occur as characteristic building blocks. Commonly, the ferrates(II/III) are mixed-valent compounds of Robin&Day class III, with magnetic properties determined by a strong antiferromagnetic coupling of the HS-Fe(2/3)+- ions. However, the magnetic moments [similar to those in pure ferrates(II) and (III)] are considerably decreased with respect to the expected 'spin-only' values, especially in the condensed polyanions. Additionally, the dimer in the new sodium salt Na7[Fe2S6] is one of the very rare examples, for which charge fluctuations result in a ferromagnetic coupling between the two Fe ions.Based on these structurally and magnectically diverse mixed-valent ferrate(II/III) salts, the aim of this project is to synthesize new alkali chalcogenido metallates(II/III) with two different cations M2+ (Mn, Co, Zn) and M3+ (Al, In), to determine their crystal structures and to measure their magnetic properties. For the newly obtained (and related) compounds, the chemical bonding is calculated using spin-polarized FP-LAPW DFT band structure methods.The investigation of these salts containing heterobimetallic polyanions, for which the ratio M(II):M(III) can be ajusted much easier than for the ferrates, does not only allow to mimic the ferrates(II/III): First results on mixed manganates/indates of this structure family show, that the crystal chemistry along the section A[MQ2]-A2[MQ2] is considerably extended by acombined edge/corner and a pure edges-sharing of [MQ4] tetrahedra. This structure diversity as well as the variation of the metal cations themselves (e.g. number of d electrons, magnetic dilution, ionic radii, M-Q bond character) results in a wide range of the chemical bonding and the physical properties. The investigation of these basic alkali salts with low(er)-dimensional metallate(II/III) anions and the comparison with the ferrates and the pure metallates(II) and (III), allows to improve the general understanding of the bonding and the magnetism also in much complexer mixed-valent systems, e.g. like those mentioned above.

混合价值硫酸基因生成（Q）铁酸酯（II/III）阴离子（A = Na，K，RB CS; Q = S，SE，TE）的碱金属（a）盐是结构上可变的化合物类别，它们是类似更为复杂系统的模型。氧化还原酶或铁基超导体。它们的晶体化学是由许多混合价值富含铁的盐（主要是通过还原性合成策略）延伸的晶体化学。沿A [FEQ2] -A2 [FEQ2]部分的四面体连接和阴离子/晶体结构特别多样化：一方面，发现了几种构象的边缘共享四面体的链，取决于Fe（II）：Fe（II）：Fe（III）和A阳离子。另一方面，[仅在混合价值的渡轮中] 4FE4S模拟四面体群集[Fe4q8]作为特征构建块出现。通常，Ferrates（II/III）是Robin＆Day III的混合价化合物，其磁性特性是由HS-FE（2/3）+离子的强抗抗铁磁耦合确定的。但是，相对于预期的“仅自旋”值，尤其是在凝聚的聚会中，相对于预期的“仅自旋”值，磁矩[与纯铁矿（II）和（iii）中的磁矩相似。 Additionally, the dimer in the new sodium salt Na7[Fe2S6] is one of the very rare examples, for which charge fluctuations result in a ferromagnetic coupling between the two Fe ions.Based on these structurally and magnectically diverse mixed-valent ferrate(II/III) salts, the aim of this project is to synthesize new alkali chalcogenido metallates(II/III)使用两个不同的阳离子M2+（Mn，Co，Zn）和M3+（Al，in），以确定它们的晶体结构并测量其磁性。 For the newly obtained (and related) compounds, the chemical bonding is calculated using spin-polarized FP-LAPW DFT band structure methods.The investigation of these salts containing heterobimetallic polyanions, for which the ratio M(II):M(III) can be ajusted much easier than for the ferrates, does not only allow to mimic the ferrates(II/III): First results on mixed manganates/indates of this结构家族表明，沿A [MQ2] -A2 [MQ2]沿线的晶体化学通过骨化边缘/角和[MQ4] Tetrahedra的纯边缘共享大大扩展。这种结构多样性以及金属阳离子本身的变化（例如D电子的数量，磁性，离子半径，M-Q键字符）会导致广泛的化学键合和物理性能。对这些具有低（ER）金属含量（II/III）阴离子（II/III）阴离子的基本碱盐的研究，以及与Ferrates和Pure Metalals（II）和（III）的比较，可以提高对键合的一般理解，并且在更加复杂的混合含量系统中，也可以提高磁性的理解。就像上面提到的那些。