Fachbereich Chemie und Wissenschaftliches Zentrum für Materialwissenschaften, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35043, Marburg, Germany.
Karlsruhe Institute of Technology (KIT), Institute of Physical Chemistry, Kaiserstraße 12, 76131, Karlsruhe, Germany.
Chemistry. 2018 Aug 14;24(46):12022-12030. doi: 10.1002/chem.201802382. Epub 2018 Jul 23.
Investigations of solid mixtures of the elemental combinations A/Tl/Pb (A=Na, K) and K/Tl/Bi indicate the presence of multiple binary and ternary Zintl phases, among them new ones containing Tl and Pb or Bi, respectively. Extractions with en/crypt-222 afford single crystals of several novel binary anions, including [Tl@Tl Pb ] and (Tl Bi ) . [Tl@Tl Pb ] adopts a closo-type cage structure despite possessing one additional electron; it is therefore isostructural, yet not isoelectronic, with homoatomic [Tl@Tl ] obtained by solid state reactions. (Tl Bi ) is a rare case of a pentagonal bipyramidal Zintl anion, yet the first binary one, and (unlike Tl ) the first one with a proper closo-type electron count. Assignment of the numbers and positions of the Tl/Pb or Tl/Bi atoms within the anionic clusters, indistinguishable in classical X-ray diffraction experiments, was achieved by means of quantum chemistry. The studies shed light on the complex situation in solid heavy element mixtures and their substantial differences from the composition of the Zintl anions obtained from them by extraction.
对元素组合 A/Tl/Pb（A=Na，K）和 K/Tl/Bi 的固态混合物的研究表明，存在多种二元和三元 Zintl 相，其中分别包含 Tl 和 Pb 或 Bi 的新相。用 en/crypt-222 萃取可以得到几种新型二元阴离子的单晶，包括[TlPb@Tl]和（TlBi）。[TlPb@Tl]尽管多了一个电子，但仍采用笼状结构，因此与通过固态反应获得的同原子[TlPb@Tl]具有相同的结构，但不是等电子的。（TlBi）是五配位双锥 Zintl 阴离子的罕见实例，但它是第一个二元阴离子，而且（与 Tl 不同）是第一个具有适当笼状电子计数的阴离子。通过量子化学，可以确定在阴离子簇内难以用经典 X 射线衍射实验区分的 Tl/Pb 或 Tl/Bi 原子的数量和位置。这些研究揭示了固体重元素混合物中的复杂情况，以及它们与通过萃取获得的 Zintl 阴离子组成之间的实质性差异。
