title: Hierarchically ordered self-assembly of amphiphilic bifullerenes.
abstract: A series of novel functionalised dumbbell-shaped bifullerenes in which two [5.0] pentakis-adducts of C60 are covalently connected by cyclic bismalonates were synthesised. These dimeric compounds, carrying various combinations of hydrophilic and hydrophobic addends, self-assemble in aqueous solution towards supramolecular architectures of different structural complexity as observed by cryogenic transmission electron microscopy (cryo-TEM). The detailed analysis of the image data revealed an unprecedented hierarchical aggregation behaviour. Whereas completely hydrophilic substituted bifullerenes formed profoundly monodisperse populations of small oligomeric elementary micelles consisting of only three or four bifullerene molecules in a supposedly bent conformation, their amphiphilic equivalents underwent a hierarchical two-step assembly process towards larger spherical and even rod-like structures. The data suggest that the hierarchical assembly process is driven by hydrophobic interactions of preformed tetrameric elementary micelles.
authors.affiliation: Department of Chemistry and Pharmacy and Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-Universität Erlangen-Nürnberg, Henkestr. 42, 91054 Erlangen (Germany).
authors.forename: Lennard
authors.initials: L
authors.lastname: Wasserthal
authors.forename: Boris
authors.initials: B
authors.lastname: Schade
authors.forename: Kai
authors.initials: K
authors.lastname: Ludwig
authors.forename: Christoph
authors.initials: C
authors.lastname: Böttcher
authors.forename: Andreas
authors.initials: A
authors.lastname: Hirsch
mesh_terms: D037741:Fullerenes / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008823:Micelles; D046529:Microscopy, Electron, Transmission; D008958:Models, Molecular; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D037741:Fullerenes; D008823:Micelles; D013501:Surface-Active Agents
keywords: aggregation; cryo-transmission electron microscopy; fullerenes; image processing; nanostructures