TY - JOUR
T1 - Supramolecular Scaffold for Tailoring the Two-Dimensional Assembly of Functional Molecular Units into Organic Thin Films
AU - Leung, Franco King Chi
AU - Ishiwari, Fumitaka
AU - Kajitani, Takashi
AU - Shoji, Yoshiaki
AU - Hikima, Takaaki
AU - Takata, Masaki
AU - Saeki, Akinori
AU - Seki, Shu
AU - Yamada, Yoichi M.A.
AU - Fukushima, Takanori
N1 - Publisher Copyright:
© 2016 American Chemical Society.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2016/9/14
Y1 - 2016/9/14
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=84987819731&partnerID=8YFLogxK
U2 - 10.1021/jacs.6b05513
DO - 10.1021/jacs.6b05513
M3 - Journal article
AN - SCOPUS:84987819731
SN - 0002-7863
VL - 138
SP - 11727
EP - 11733
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 36
ER -