Experimental characterization of the chemical bonds in boron allotropes and boron-rich compounds

硼同素异形体和富硼化合物中化学键的实验表征

• 批准号: 244734497
• 负责人: Professor Dr. Sander van Smaalen
• 金额: --
• 依托单位: Laboratorium für Kristallographie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/244734497?language=en
• 关键词: Experimental; characterization; chemical; bonds; boron

Chemical bonding involving boron atoms is not understood, despite intensive research over many years. For example, it is not known, which allotrope of boron is the stable form at ambient conditions. This project aims at an experimental characterization by single-crystal X-ray diffraction of allotropes of boron, like beta-B106 und alpha-tetragonal boron, and boron-rich solids, like B13C2 and B50C2. Structure refinements of the multipole (MP) model and data analysis according to the Maximum Entropy Method (MEM) will produce electron-density maps that reflect the spatial distribution of the valence electrons in full detail. A quantitative topological analysis of electron densities according to Bader's Atoms-in-Molecules (AIM) theory will classify the different kinds of chemical interactions through bond critical points (BCP), ring critical points (RCP) and bond paths. Next to normal two-electron-two-center (2e2c) bonds between pairs of atoms, we expect that the electron deficient nature of the boron atom will lead to polycenter bonds, two-electron-three-center (2e3c) bonds and one-electron-two-center (1e2c) bonds of various types. Goal is to develop a generalized description of chemical bonds involving boron atoms across the different allotropes and compounds.

尽管多年来进行了大量的研究，但涉及硼原子的化学键尚不清楚。例如，还不知道在环境条件下，哪种硼的同素异形体是稳定的形式。本项目旨在通过单晶X射线衍射法对硼的同素异形体，如β-B106和α-四方形硼，以及富硼固体，如B13C2和B50C2进行实验表征。多极(MP)模型的结构改进和根据最大熵方法(MEM)进行的数据分析将产生全面反映价电子空间分布的电子密度图。根据Bader原子分子(AIM)理论对电子密度的定量拓扑分析将通过键临界点(BCP)、环临界点(RCP)和键路径对不同类型的化学相互作用进行分类。除了正常的原子对之间的双电子双中心(2e2c)键，我们预计硼原子的缺电子性质将导致各种类型的多中心键、双电子三中心(2e3c)键和单电子双中心(1e2c)键。目标是开发一个涉及不同同素异形体和化合物中的硼原子的化学键的通用描述。

项目成果

Electrostatic potential in crystals of α-boron, γ-boron and boron carbide

α-硼、γ-硼和碳化硼晶体中的静电势

• DOI: 10.1515/zkri-2018-2080
• 发表时间: 2018
• 期刊: Zeitschrift für Kristallographie - Crystalline Materials
• 作者: C. B. Hübschle ;S. van Smaalen
• 通讯作者: S. van Smaalen