Single-Crystal X-ray Diffraction Studies of Solvated Crystals of C60 Reveal the Intermolecular Interactions between the Component Molecules

Abstract

The solid-state structures of seven solvates of C60 (C60·4tetrachloroethylene, C60·2tetrachloroethylene, C60·3benzene, C60· n-pentane, C60·diethyl ether, C60·chlorobenzene, and C60·benzene·dichloromethane) were determined by single-crystal X-ray diffraction at low temperature. At 90 K, the fullerene and solvate components are generally well-ordered and do not show the orientational disorder that plagues similar structures determined at room temperature. Interactions between the solvate molecules and the fullerene and between adjacent C60 molecules were examined and analyzed. Van der Waals and weak charge-transfer interactions are important to help to organize the individual components in these structures. The weak Lewis acid behavior of C60, such as when it cocrystallizes with diethyl ether or chlorinated solvents, is apparent. In addition, π-stacking interactions are prevalent. The solvates of C60 reported here were frequently obtained from attempts to cocrystallize C60 with another chemical compound. Although the desired cocrystals were never formed, the unincorporated molecules influenced solvate formation.