Morphological transition of a conductive molecular organization with non-covalent from nanonetwork to nanofiber.
The formation of nanofiber morphology at a mesoscopic scale, and molecular level stacking of a tetrathiafulvalene (TTF) derivative with a chiral group were investigated by the one-dimensional growth method in interfacial molecular films. Monomolecular films of a TTF derivative with a chiral borneol group display a two-dimensional phase transition at the air/water interface. At high surface pressures, nanonetwork domains are formed, where the TTF molecular planes are densely packed with an interlayer distance of 4.1 Å. The formation of this network is attributed to the organized aggregation of the TTF derivatives, which is a result of strong intermolecular interactions. Subsequently, the growth of morphology is encouraged by the application of the one-dimensional growth method at low surface pressure conditions, varying compression speeds, and subphase temperatures. At low surface pressure and a subphase temperature of 15 °C, the TTF derivatives aggregated as nanofibers with close packing of molecules. Upon raising the subphase temperature, the thickness of the nanofibers was found to increase and hence, spontaneous morphogenesis at the air/water interface was achieved.
Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan. Electronic address: fujimori@fms.saitama-u.ac.jp.
Atsuhiro
A
Fujimori
Department of Functional Materials Science, Faculty of Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan.
Rie
R
Yamato
Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan.
Takahiro
T
Kikkawa
Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakamachi, Koganei, Tokyo 184-8588, Japan. Electronic address: ytatewa@cc.tuat.ac.jp.
Yoko
Y
Tatewaki
Chiral group; Conductive molecular films; Morphological transition from nanonetwork to nanofiber; One-dimensional growth; TTF derivative