title: Supramolecular Scaffold for Tailoring the Two-Dimensional Assembly of Functional Molecular Units into Organic Thin Films.
abstract: Tailoring structurally anisotropic molecular assemblies while controlling their orientation on solid substrates is an important subject for advanced technologies that use organic thin films. Here we report a supramolecular scaffold based on tripodal triptycene assemblies, which enables functional molecular units to assemble into a highly oriented, multilayered two-dimensional (2D) structure on solid substrates. The triptycene building block carries an ethynyl group and three flexible side chains at the 10- and 1,8,13-positions, respectively. These bridgehead-substituted tripodal triptycenes self-assembled on solid substrates to form a well-defined "2D hexagonal + 1D lamellar" structure, which developed parallel to the surface of the substrates. Remarkably, the assembling properties of the triptycene building blocks, particularly for a derivative with tri(oxyethylene)-containing side chains, were not impaired when the alkyne terminal was functionalized with a large molecular unit such as C60, which is comparable in diameter to the triptycene framework. Consequently, thin films with a multilayered 2D assembly of the C60 unit were obtained. Flash-photolysis time-resolved microwave conductivity (FP-TRMC) measurements revealed that the C60 film exhibits highly anisotropic charge-transport properties. Bridgehead-substituted tripodal triptycenes may provide a versatile supramolecular scaffold for tailoring the 2D assembly of molecular units into a highly oriented thin film, and in turn for exploiting the full potential of anisotropic molecular functions.
authors.affiliation: Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology , 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.|RIKEN Center for Sustainable Resource Science , Wako, Saitama 351-0198, Japan.|RIKEN SPring-8 Center , 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan.
authors.forename: Franco King-Chi
authors.initials: FK
authors.lastname: Leung
authors.affiliation: Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology , 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.|RIKEN SPring-8 Center , 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan.
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Ishiwari
authors.affiliation: Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology , 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.|RIKEN SPring-8 Center , 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kajitani
authors.affiliation: Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology , 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.|RIKEN SPring-8 Center , 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Shoji
authors.affiliation: RIKEN SPring-8 Center , 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Hikima
authors.affiliation: RIKEN SPring-8 Center , 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan.|Institute of Multidisciplinary Research for Advanced Materials, Tohoku University , Sendai 980-8577, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Takata
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka University , 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Saeki
authors.affiliation: Department of Molecular Engineering, Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Shu
authors.initials: S
authors.lastname: Seki
authors.affiliation: RIKEN Center for Sustainable Resource Science , Wako, Saitama 351-0198, Japan.
authors.forename: Yoichi M A
authors.initials: YM
authors.lastname: Yamada
authors.affiliation: Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology , 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Fukushima