Departmental Bulletin Paper シクロデキストリン水溶液中におけるプロポクサーの2 光子イオン化

竹下, 達哉  ,  Takeshita, Tatsuya  ,  北畑, 香純  ,  Kitabata, Kasumi  ,  笠羽, 祐太  ,  Kasaba, Yuuta  ,  原, 道寛  ,  Hara, Michihiro,

Resonance two-photon ionization (TPI) of Propoxur (o-isopropoxyphenyl methylcarbamate : MC), a typical agricultural chemical was demonstrated using 266-nm laser flash photolysis (LFP) technique in the presence of cyclodextrins (CDs) in aqueous solution. The formation of the MC/CDs inclusion complex was studied by MM2 calculations. Ionization of MC within the laser flash (5 ns) produced a water solvated electron. The electron was generated by two-photon excitation by means of simultaneous irradiation from a266-nm laser. The ionization quantum yield (Φion) obtained by LFP in the presence ofα-, β-and γ-CD were 0.35±0.02%, 0.15±0.01%and 0.61±0.01%, respectively, and it depended on the properties of the complexes with CDs. These behaviors suggest that the useful resonance two-photon ionization results from the complexes of MC and α-CD, β-CD and γ-CD, respectively. The Φion of MC in the presence of CDs (1.0×10-2M) is dependent on the stabilization energy of solvation. In addition, Φion of MC in the presence of CDs (1.0×10-3M) was dependent on the τ. This study suggests photolysis of agricultural chemicals in the presence of CDs in aqueous solvent using two-photon ionization of UV light irradiation.

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