Aryl-Aryl Interactions in (Aryl-Perhalogenated) 1,2-Diaryldisilanes

Autor: Marvin Linnemannstöns, Hans-Georg Stammler, Beate Neumann, Norbert W. Mitzel, Raphael J. F. Berger, Jan Schwabedissen
Rok vydání: 2019
Předmět:
Zdroj: Chemistry (Weinheim an Der Bergstrasse, Germany)
ISSN: 1521-3765
Popis: Three 1,2‐diaryltetramethyldisilanes X5C6‐(SiMe2)2‐C6X5 with two C6H5, C6F5, or C6Cl5 groups were studied concerning the importance of London dispersion driven interactions between their aryl groups. They were prepared from 1,2‐dichlorotetramethyldisilane by salt elimination. Their structures were determined in the solid state by X‐ray diffraction and for free molecules by gas electron‐diffraction. The solid‐state structures of the fluorinated and chlorinated derivatives are dominated by aryl–aryl interactions. Unexpectedly, Cl5C6‐(SiMe2)2‐C6Cl5 exists exclusively as an eclipsed syn‐conformer in the gas phase with strongly distorted Si‐C6Cl5 units due to strong intramolecular interactions. In contrast, F5C6‐(SiMe2)2‐C6F5 reveals weaker interactions. The contributions to the total interaction energy were analyzed by SAPT calculations.
An eclipsed syn‐conformation is exclusively observed for Cl5C6‐(SiMe2)2‐C6Cl5 in the solid and gaseous phase with strongly distorted Si‐C6Cl5 units; it demonstrates the strikingly different ability of phenyl, pentafluorophenyl and pentachlorophenyl substituents to exert aryl–aryl stacking interactions (see figure).
Databáze: OpenAIRE