分子ビームでトロウエンのフォトアイソメリゼーションと光解離
Chih-Kai Lin1, Cheng-Liang Huang, Jyh-Chiang Jiang
1Institute of Atomic and Molecular Science, Academia Sinica, P.O. Box 23-166, Taipei, Taiwan.
Journal of the American Chemical Society
|April 11, 2002
まとめ
イソトープで標識されたトロウエンの光解離は,分解する前に,サイクロヘプタトリエンの25%のイソメリゼーションを明らかにします. この経路は,アルキル基と芳香環の間の原子交換を伴うので,直接の結合割れと競合する.
科学分野:
- 化学物理 化学物理
- フォトケミストリー フォトケミストリー
- 分子ダイナミクス 分子ダイナミクス
背景:
- トロウエンの光解離は,炭化水素化学の理解に不可欠です.
- 同位体ラベリングは,反応機構と原子乱雑に関する洞察を提供します.
研究 の 目的:
- 6.4 eVの同位体ラベル付トルーエンの光解離経路を調査する.
- 競合する解離と異体化チャネルを特定し,定量化する.
- 193 nmのトルーエンの解離率を測定する.
主な方法:
- イソトープラベル付トルーエン (C ((6) H ((5) CD ((3)),C ((6) H ((5) 13) CH ((3)) を使った衝突のない光解離実験.
- フォトフラグメントを分析するためのマルチマスイオンイメージング技術.
- 断片種とその起源を特定するための光譜分析.
主要な成果:
- サイクロヘプタトリエンへのイソメリゼーションを示す予期せぬ写真断片が観察されました (25%の興奮したトロウエンは).
- イソメリゼーション中のアルキル群と芳香環の間の原子交換が実証された.
- 193 nm でトロウエンの解離率を (1.17 ± 0.1) x 10^6 s^-1.0 として測定しました.
結論:
- トロウエンの光解離には,直接の結合割れと競合する重要な異体化経路が含まれます.
- イソメリゼーションにより,アルキルとアロマティック部分の間で広範な原子乱れが生じます.
- 測定された解離速度は,トルーエンの光化学の重要な運動パラメータを提供します.
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