Rudjer Bošković Institute, Bijenička 54, 10000, Zagreb, Croatia.
Department of Chemistry and Institute of Soft Matter, Georgetown University, 424 Regents Hall, Washington, DC, 20057-1227, USA.
Chemistry. 2018 Jun 12;24(33):8292-8297. doi: 10.1002/chem.201800672. Epub 2018 May 15.
The crystal structure of [4-damp]) [Cl Q] (4-damp=4-dimethylamino-N-methylpyridinium, Cl Q=tetrachloroquinone) salt is built up from slipped columnar stacks of quinoid rings composed of closely bound trimers with the intra-trimer separation distance of 2.84 Å and total charge of -2 whereas the inter-trimer distance is 3.59 Å. The individual rings exhibit partial negative charges that are distributed unevenly among the three Cl Qs in the trimer. The strong interactions within a trimer (Cl Q) have a partially covalent character with two-electron/multicentered bonding, that is extended over three rings, plausibly termed as "pancake bonding". The electron pairing within this multicentre bond leads to the fact that the crystals are diamagnetic and act as insulators. The studies of the structure and nature of bonding are based on X-ray charge density analysis and density functional theory.
[4-二甲基氨基-N-甲基吡啶鎓]四氯对醌盐的晶体结构
[4-二甲基氨基-N-甲基吡啶鎓]四氯对醌盐的晶体结构由紧密结合的三聚体组成的准柱状堆积构成，三聚体中每个环呈现部分负电荷，且不均匀地分布在三个四氯对醌上，三聚体的内部分离距离为 2.84 Å，总电荷为-2，而三聚体之间的距离为 3.59 Å。该晶体结构的研究基于 X 射线电荷密度分析和密度泛函理论。晶体结构中，部分电子配对导致晶体呈现抗磁性，表现为绝缘体。这种堆积由扭曲的柱状层组成，其中准一维的醌环彼此平行排列。
