P. Brough, D. Bonifazi, M. Prato,
Tetrahedron 2006, 62, 2110-2114
The aggregation of four charged C60 derivatives has been investigated by TEM, SEM, and AFM microscopies. In all molecules a short aliphatic chain connects an ammonium cation to the fullerene sphere and the variation comes in the counter anions. In water, remarkably well-ordered structures that resemble nanorod-like aggregates are formed. They have a cross-sectional diameter and a length in the range of 30–60 and 100–900 nm, respectively. Fine topographical details were elucidated by atomic force microscopy, in which the height was found up to a maximum of 60 nm. Scanning electron microscopy shows that both the shape and morphology of the aggregates is consistent throughout the material. Nanorods of uniform shape were obtained with all molecules containing inorganic counter anions, BF4−, Br−, and Cl−.