Hydrogenation as an instrument for modifying structures and properties of certain classes ofintermetallics and inorganic metal-rich compounds

该项目的基本目标是进一步发展氢化作为修饰金属间化合物和无机富金属化合物的结构和性质的工具，研究氢插入的基本原理，并建立这些金属氢化物的结构-性质关系及其操纵的化学方法。在项目范围内，我们的目标是基于金属间化合物的某些结构类别合成新的金属氢化物，以及上述类别的新的金属间化合物，表征它们的晶体结构，建立所讨论的化合物的结构-性质关系，表征复杂和金属间氢化物的键和氢的电子状态，开发一种有效的预测金属间化合物对氢的反应性的方法。研究有利于金属间化合物加氢的因素（热力学计算）及其与结构和键合的可能联系，并为复杂金属间化合物基体系在储氢、脆化和催化方面的潜在应用制定指导方针。我们对基于d和f金属的键系统特别感兴趣，因为它们为不同种类的元素组合和键模式的变化提供了很多可能性，并且通常不太了解。我们将研究插入氢对结构和性能的影响，重点研究基于特定结构类型和元素比例的几类化合物。这类化合物包括MNi3、MPd3、MPt3和MLn3类型的二元金属间化合物（M =主族金属，Ln =镧系元素），MNi2和MPd2类型的二元金属间化合物（M = s、p、d或f金属），以及MTX-（“111”）和ZrSiCuAs-（“1111”）类型的某些化合物（M =碱土或镧系元素；T =过渡金属或Mg； X = Si、Ge、Sn）。化合物的表征将基于x射线单晶研究、x射线和中子粉末衍射（包括原位研究）、电子显微镜、微探针分析、热分析和电磁测量。电子结构将基于DFT计算进行研究，键合分析将在直接空间和轨道空间进行。莫斯科罗蒙诺索夫州立大学和莱比锡大学小组的联合研究将利用双方在专门知识和基础设施方面的互补性，并将提供定期交换研究人员的机会，以便在两个小组之间传播具体的知识和专门知识。因此，我们期望获得关于金属间化合物加氢、控制氢化物结构稳定性的原理、复杂无机氢化物的结构-性质关系以及调节这些性质的化学方法的新的系统知识；我们还旨在就这些化合物的潜在用途提出建议，作为新功能材料的基础。

The project has the fundamental aim of further developing hydrogenation as an instrument for modifying structures and properties of intermetallics and inorganic metal-rich compounds, to investigate the fundamental principles of hydrogen insertion, and to establish structure-property relationships for such metal hydrides and chemical ways of their manipulation. Within the scope of the project we aim to synthesize new metal hydrides based on certain structural classes of intermetallics, as well as new intermetallics of said classes, to characterize their crystal structures, to establish structure-property relationships for the compounds in question, to characterize bonding in complex and intermetallic hydrides and the electronic state of hydrogen, to develop a working predictive approach to the reactivity of intermetallics towards hydrogen, to investigate the factors that favor hydrogenation of intermetallics (calculation of thermodynamics) and their possible connection to structure and bonding, and to formulate guidelines for potential applications of complex intermetallic-based systems for hydrogen storage, embrittlement, and catalysis. We are particularly interested in the bond systems based on d- and f-metals, since these offer a lot of possibilities for different kinds of element combinations and variations in bonding patterns, and are generally less well understood. We will study the influence of hydrogen insertion on structures and properties, focusing on several classes of compounds based on specific structure types and element ratios. These classes include binary intermetallics of the MNi3, MPd3, MPt3 and MLn3 types (M = main-group metal, Ln = lanthanide), of the MNi2 and MPd2 types (M = s, p, d, or f metal), and certain compounds of the MTX- (“111”) and ZrSiCuAs- (“1111”) types (M = alkaline earth or lanthanide; T = transition metal or Mg; X = Si, Ge, Sn). Characterization of the compounds will be based on X-ray single-crystal investigations, X-ray and neutron powder diffraction (including in situ studies), electron microscopy, microprobe analysis, thermal analysis, and galvanomagnetic measurements. Electronic structures will be studied based on DFT calculations and bonding analysis will be performed both in direct and orbital space. Joint research of the groups from Lomonosov Moscow State and Leipzig Univ. will make use of the complementarity of both sides regarding expertise and infrastructure, and will also offer an opportunity of regular researcher exchange in order to disseminate specific knowledge and expertise between both groups. As a result, we expect to gain new systematic knowledge about hydrogenation of intermetallics, the principles governing stability of the structures of hydrides, the structure-property relationships in complex inorganic hydrides and chemical ways of tuning said properties; we also aim to develop recommendations on the potential use of the compounds in question as the basis for new functional materials.