イリタニ コウヘイ
  入谷 康平
   所属   工学部 応用化学科
   職種   助教
言語種別 英語
発行・発表の年月 2019/10
形態種別 学術論文
査読 査読あり
標題 Electrostatically Driven Guest Binding in Self-Assembled Molecular Network of Hexagonal Pyridine Macrocycle at the Liquid/Solid Interface: Symmetry Breaking Induced by Coadsorbed Solvent Molecules
執筆形態 共著
掲載誌名 Langmuir
掲載区分国外
出版社・発行元 American Chemical Society
巻・号・頁 35(47),pp.15051-15062
著者・共著者 Kohei Iritani, Hiroshi Takeda, Michael Kather, Masahiko Yokoi, Magali Moeglen, Motoki Ikeda, Yusuke Otsubo, Yu Ozawa, Kazukuni Tahara, Keiji Hirose, Steven De Feyter, Yoshito Tobe
概要 We present here the construction of a self-assembled two-dimensional (2D) porous monolayer bearing a highly polar 2D space to study guest co-adsorption through electrostatic interactions at the liquid/solid interface. For this purpose, a dehydrobenzo[12]annulene (DBA) derivative, DBA-TeEG, having tetraethylene glycol (TeEG) groups at the end of the three alternating alkoxy chains connected by p-phenylene linkers was synthesized. As a reference host molecule, DBA-C10, having nonpolar C10 alkyl chains at three alternating terminals, was employed. As guest molecules, hexagonal phenylene–ethynylene macrocycles (PEMs) attached by triethylene glycol (TEG) ester and hexyl ester groups, PEM-TEG and PEM-C6, respectively, at each vertex of the macrocyclic periphery were used. Scanning tunneling microscopy observations at the 1,2,4-trichlorobenzene/highly oriented pyrolytic graphite interface revealed that PEM-TEG was immobilized in the pores formed by DBA-TeEG at higher probability because of electrostatic interactions such as dipole–dipole and hydrogen bonding interactions between oligoether units of the host and guest, in comparison to PEM-C6 with nonpolar groups. These observations are discussed based on molecular mechanics simulations to investigate the role of the polar functional groups. When a nonpolar host matrix formed by DBA-C10 was used, however, only phase separation and preferential adsorption were observed; virtually no host–guest complexation was discernible. This is ascribed to the strong affinity between the guest molecules which form by themselves densely packed van der Waals networks on the surface.