Bende David, Wagner Frank R, Grin Yuri
Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Straße 40, 01187 Dresden, Germany.
Inorg Chem. 2015 Apr 20;54(8):3970-8. doi: 10.1021/acs.inorgchem.5b00135. Epub 2015 Apr 3.
The chemical bonding of main-group MgAgAs-type compounds is analyzed with quantum chemical direct-space techniques. A new bonding concept is developed that unites the former ionic bonding and polyanionic network models. Polar and nonpolar contributions to the bonding are extracted by the combined analysis of electron density and electron localizability. A direct-space representation of the 8 - N rule is introduced. In this approach, the anions' heteropolar bonds are treated as a superposition of covalent (nonpolar) and lone-pair closed-shell (polar) contributions. The relation between covalent (nonpolar) and lone-pair (polar) character is obtained with the ELI-D/QTAIM basin intersection technique. This ratio depends on the constituting elements. On basis of this approach, MgAgAs-type compounds are compared with Zintl phases, where covalent bonds and lone pairs are spatially separated.
采用量子化学直接空间技术分析了主族MgAgAs型化合物的化学键合。提出了一种新的键合概念，将以前的离子键合和聚阴离子网络模型统一起来。通过对电子密度和电子定域性的综合分析，提取了键合中的极性和非极性贡献。引入了8 - N规则的直接空间表示。在这种方法中，阴离子的异极键被视为共价（非极性）和孤对闭壳层（极性）贡献的叠加。利用ELI-D/QTAIM盆地相交技术得到了共价（非极性）和孤对（极性）特征之间的关系。该比例取决于组成元素。基于这种方法，将MgAgAs型化合物与共价键和孤对在空间上分离的津特耳相进行了比较。
