Insights into the Topology and the Formation of a Genuine ppσ Bond: Experimental and Computed Electron Densities in Monoanionic Trichlorine [Cl<sub>3</sub>]<sup>−</sup>
Helena Keil, Karsten Sonnenberg, Carsten Müller, Regine Herbst‐Irmer, Helmut Beckers, Sebastian Riedel, Dietmar Stalke
Abstract
Abstract So far, several publications have discussed the bonding concepts in polyhalides on a theoretical basis. In particular, the trichlorine monoanion is of great interest because its structure should be symmetrical and show two equidistant Cl−Cl bonds. However, apart from matrix‐isolation studies, only asymmetric trichlorine anions have been reported so far. Herein, the trichlorine monoanions in 2‐chloroethyltrimethylammonium trichloride [NMe 3 EtCl][Cl 3 ], 1 , tetramethylammonium trichloride [NMe 4 ][Cl 3 ], 2 , and tetrapropylammonium trichloride [NnPr 4 ][Cl 3 ], 3 , are analysed. High‐resolution X‐ray structures and experimental charge density analyses supported by periodic quantum‐chemical calculations provide insight into the influence of the crystalline environment on the structure of these [Cl 3 ] − anions as well as into the progress of the bond formation between a dichlorine molecule and a Cl − anion.