Synthesis and anion sensing property of poly(phenylacetylene) bearing urea derivative of L-leucine as pendant

POLY 455

Ryohei Kakuchi, rk_ryohei@poly-bm.eng.hokudai.ac.jp, Sachiko Nagata, nagata@poly-bm.eng.hokudai.ac.jp, Ryosuke Sakai, sakai@poly-mc.eng.hokudai.ac.jp, Takafumi Yonekawa, yonekawa@poly-bm.eng.hokudai.ac.jp, Issei Otsuka, otsuka@poly-bm.eng.hokudai.ac.jp, Toshifumi Satoh, satoh@poly-mc.eng.hokudai.ac.jp, and Toyoji Kakuchi, kakuchi@poly-mc.eng.hokudai.ac.jp. Graduate School of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Japan
We successfully polymerized the phenylacetylene with the urea derivative of L-leucinethe (1) to afford cis-poly(phenylacetylene) bearing the urea derivative of L-leucine as pendant (2). Polymer 2 showed a distinct Cotton effect in the range from 280 nm to 520 nm due to the absorption of the polymer backbone, demonstrating that 2 possessed a one-handed helical screw sense. The CD and absorption spectra of 2 in the presence of the tetra-n-butylammonium nitrate (TBAN), hydrosulfate (TBAHS), fluoride (TBAF), and acetate (TBAA) showed a characteristic spectral pattern, so that 2 was applicable for the selective detection of anionic species. Especially for TBAA, the helical pitch of 2 was drastically changed through the strong host-guest complexation of urea with the acetate anion, which realized the selective and visible sensing of carboxylate anion. This is the first demonstration of an anion sensor utilizing a combination of poly(phenylacetylene) and host-guest chemistry.