Rotor-stator molecular crystals of fullerenes with cubane.
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.
Pekker
Sándor
S
Research Institute for Solid State Physics and Optics, Hung. Acad. Sci., H-1525 Budapest, PO Box 49, Hungary. pekker@szfki.hu
Kováts
Eva
E
Oszlányi
Gábor
G
Bényei
Gyula
G
Klupp
Gyöngyi
G
Bortel
Gábor
G
Jalsovszky
István
I
Jakab
Emma
E
Borondics
Ferenc
F
Kamarás
Katalin
K
Bokor
Mónika
M
Kriza
György
G
Tompa
Kálmán
K
Faigel
Gyula
G
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
D017554:Carbon Compounds, Inorganic; D037741:Fullerenes; D020409:Molecular Motor Proteins