Recognition-Control and Host–Guest Interactions in High-Symmetry Cocrystals of Fullerenes with Cubane and Mesitylene

Abstract

The limited success in the prediction of structure is one of the most serious problems in the engineering of molecular crystals. Here we show that the packing of high-symmetry molecules such as ball-shaped rotating fullerenes, cube-shaped cubane, and octahedral-shaped mesitylene dimers give rise to the formation of cubic cocrystals with easily predictable lattice parameters. We present the synthesis and structure determination of Sc 3 N@C 80 -I h cocrystals with cubane (C 8 H 8 ) and mesitylene (C 9 H 12 ) and compare the new materials with related C 60 -and C 70 -based structures. In this family of materials, most atom-to-atom interactions are averaged out by the symmetry, and the crystal structures can be described in terms of classical molecule-to-molecule interactions. Size-dependent homoand heteromolecular contacts control the stability of the ball-cube and ball-octahedron systems creating several host−guest and recognition-controlled regions. The analysis of the global phase diagrams explains not only the stability of the observed materials, but also the instability of a missing derivative.

Mechanical Properties of Cubene Crystals

“…At higher temperatures, there is a transition to an orientationally disordered fcc lattice [ 46 ]. As can be seen, many studies have been carried out to predict and analyze the structure of fullerites C and C , but we have not been able to find any information about the structure for fullerite C except for the study [ 47 ] where cubic cubane C H was described. In the present study, we set ourselves the task of finding the equilibrium phases of a cubene crystal and their mechanical properties.…”