title: Remarkable enhancement of the photoreactivity of a polyfluoroalkyl azobenzene derivative in an organic-inorganic nano-layered microenvironment.
abstract: Organic-inorganic hybrids composed of polyfluoroalkyl azobenzene surfactant (abbreviated as C3F-Azo-C6H) and inorganic layered compounds are able to undergo reversible three-dimensional morphology changes such as interlayer space changes and nanosheet sliding in a giant scale due to reversible trans-cis isomerization of the azobenzene moiety upon photo-irradiation. In this paper, we have systematically studied the relationship between the layered hybrid microstructures of C3F-Azo-C6H-clay and their photoreactivity for understanding the mechanism of the photo-induced morphology change. The photoreactivity was found to be very much affected by the surrounding microenvironments. As compared with it in solution, the cis-trans photo-isomerization in C3F-Azo-C6H-clay nano-layered film was substantially enhanced with the quantum yield exceeding unity (Φ = 1.9), while the trans-cis isomerization was rather retarded. The corresponding hydrocarbon analogue of the azobenzene surfactant (C3H-Azo-C6H) did not show such an enhancement. The enhancement was discussed in terms of a cooperative effect among adjacent azobenzene moieties along with polyfluoroalkyl chains and the inorganic clay nanosheet to prevent a dissipation of the excess energy being liberated during the photo-isomerization within the nano-layered microenvironment.
authors.affiliation: Department of Applied Chemistry, Tokyo Metropolitan University, 1-1 Minami-osawa, Hachioji, 192-0397, Japan. inoue-haruo@tmu.ac.jp.
authors.forename: Vivek
authors.initials: V
authors.lastname: Ramakrishnan
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yamamoto
authors.forename: Shin
authors.initials: S
authors.lastname: Sasamoto
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Shimada
authors.forename: Yu
authors.initials: Y
authors.lastname: Nabetani
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tachibana
authors.forename: Haruo
authors.initials: H
authors.lastname: Inoue