Spontaneous molecular assembly in solution usually proceeds under thermodynamic control and thus provides a reliable approach to creating materials with high positional and/or orientational order of the constituent molecules.  If supramolecular building blocks could be purposely designed, one may control the alignment of functional molecular units so that the resulting assembly can take full advantage of the inherent properties of the functional units.  This presentation will focus on the controlled assembly of C₆₀ using several supramolecular building blocks.  When C₆₀ is attached to a particular type of hexabenzocoronene capable of forming a nanotubular assembly, a coaxial nanotube results, where the wall consists of hole-transporting hexabenzocoronene arrays, while inner and outer surfaces are covered by an electron-transporting monolayer of C₆₀ [1].  We have also shown that an amphiphilic design of an oligothiophene-C₆₀ dyad provides a rational strategy for tailoring bicontinuous electron donor and acceptor arrays [2].  We recently found that a tripodal triptycene self-assembles into a 2D hexagonal structure by nested packing. The interpenetration of the triptycene part may suppress structural fluctuation, thus enabling the formation of organic films with a remarkably long-range structural order [3].  Using this tripodal triptycene as a supramolecular building block, a C₆₀ unit can be assembled into a two-dimensional sheet-like structure.  The synthesis and properties of these materials with controlled C₆₀assemblies will be discussed.

References: [1] Y. Yamamoto, G. Zhang, W. Jin, T. Fukushima, N. Ishii, A. Saeki, S. Seki, S. Tagawa, T. Minari, K. Tsukagoshi, T. Aida, Proc. Natl. Acad. Sci. U.S.A. 2009, 106, 21051–21056.  [2] W.-S. Li, Y. Yamamoto, T. Fukushima, A. Saeki, S. Seki, S. Tagawa, H. Masunaga, S. Sasaki, M. Takata, T. Aida, J. Am. Chem. Soc. 2008, 130, 8886­–8887.  [3] N. Seiki, Y. Shoji, T. Kajitani, F. Ishiwari, A. Kosaka, T. Hikima, M. Takata, T. Someya, T. Fukushima, Science 2015, 348, 1122–1126.