報文

粘土鉱物モンモリロナイトへのアゾベンゼンの新規挿入法と分光学的評価

A New Intercalation Method of Azobenzene into Montmorillonite and Its Spectroscopic Evaluation

氏家 賢二・篠崎 良太・工藤 　聡・中戸 晃之・中田 宗隆
Kenji UJIKE, Ryota SHINOZAKI, Satoshi KUDOH, Teruyuki NAKATO, and Munetaka NAKATA

モンモリロナイトの層間を界面活性剤によって有機修飾することなく，アゾベンゼンを直接挿入させる新規合成法を考案した．赤外吸収スペクトル，X線回折パターンの測定から，アゾベンゼンが層間に挿入されたことを確認した．光照射を行った後に測定した紫外可視吸収スペクトル，X線回折パターンから，アゾベンゼンの可逆的な光異性化による約0.03〜0.04 nmの基本面間隔の可逆的な変化を確認した．

We tried to intercalate azobenzene into the interlayer spaces of montmorillonite by mixing fused azobenzene with solid montmorillonite after removing water molecules in the interlayer spaces by heating. The intercalation of azobenzene was confirmed by measuring the IR spectra and X-ray diffraction patterns. This is a new method of intercalation by use of the weak interaction between azobenzene and montmorillonite, which is different from previous methods of intercalation, where either azobenzene is modified by an ionic substituent or montmorillonite is modified by an ionic surfactant. Reversible changes in the basal spacing of about 0.03~0.04 nm by UV or Vis irradiation were confirmed by the corresponding reversible changes in the electronic absorption spectra and the X-ray diffraction patterns. A new model of intercalation is proposed, such that planar trans azobenzene molecules, which exist parallel to one another in the layers, dilate the interlayer by photoisomerization to non-planar cis azobenzene.

Keywords:Montmorillonite, Azobenzene, Intercalation, Photoisomerization, UV-Vis spectra