title: Rotor-stator molecular crystals of fullerenes with cubane.
abstract: Cubane (C8H8) and fullerene (C60) are famous cage molecules with shapes of platonic or archimedean solids. Their remarkable chemical and solid-state properties have induced great scientific interest. Both materials form polymorphic crystals of molecules with variable orientational ordering. The idea of intercalating fullerene with cubane was raised several years ago but no attempts at preparation have been reported. Here we show that C60 and similarly C70 form high-symmetry molecular crystals with cubane owing to topological molecular recognition between the convex surface of fullerenes and the concave cubane. Static cubane occupies the octahedral voids of the face-centred-cubic structures and acts as a bearing between the rotating fullerene molecules. The smooth contact of the rotor and stator molecules decreases significantly the temperature of orientational ordering. These materials have great topochemical importance: at elevated temperatures they transform to high-stability covalent derivatives although preserving their crystalline appearance. The size-dependent molecular recognition promises selective formation of related structures with higher fullerenes and/or substituted cubanes.
authors.affiliation: Research Institute for Solid State Physics and Optics, Hung. Acad. Sci., H-1525 Budapest, PO Box 49, Hungary. pekker@szfki.hu
authors.forename: Sándor
authors.initials: S
authors.lastname: Pekker
authors.forename: Eva
authors.initials: E
authors.lastname: Kováts
authors.forename: Gábor
authors.initials: G
authors.lastname: Oszlányi
authors.forename: Gyula
authors.initials: G
authors.lastname: Bényei
authors.forename: Gyöngyi
authors.initials: G
authors.lastname: Klupp
authors.forename: Gábor
authors.initials: G
authors.lastname: Bortel
authors.forename: István
authors.initials: I
authors.lastname: Jalsovszky
authors.forename: Emma
authors.initials: E
authors.lastname: Jakab
authors.forename: Ferenc
authors.initials: F
authors.lastname: Borondics
authors.forename: Katalin
authors.initials: K
authors.lastname: Kamarás
authors.forename: Mónika
authors.initials: M
authors.lastname: Bokor
authors.forename: György
authors.initials: G
authors.lastname: Kriza
authors.forename: Kálmán
authors.initials: K
authors.lastname: Tompa
authors.forename: Gyula
authors.initials: G
authors.lastname: Faigel
mesh_terms: D017554:Carbon Compounds, Inorganic / Q000032:analysis / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D037741:Fullerenes / Q000032:analysis / Q000737:chemistry*; D006358:Hot Temperature; D008422:Materials Testing; D008968:Molecular Conformation; D020409:Molecular Motor Proteins / Q000737:chemistry*; D049329:Nanostructures / Q000032:analysis / Q000737:chemistry* / Q000648:ultrastructure*; D044367:Phase Transition
chemical_list: D017554:Carbon Compounds, Inorganic; D037741:Fullerenes; D020409:Molecular Motor Proteins