水性ニトラートの主要な光力学:ペロキシニトリートの形成

Dorte Madsen¹, Jane Larsen, Svend Knak Jensen

¹Department of Chemistry, University of Aarhus, Langelandsgade 140, DK-8000, Aarhus, Denmark.

Journal of the American Chemical Society

|December 11, 2003

まとめ

200 nmの水性窒素イオン (NO3-) の光化学反応は,主にシス-ペロキシニトリットを産生する. いくつかの興奮した窒素イオンが基本状態に戻り,少数のイオンがNOとO2に解離する.

科学分野:

フォトケミストリーフォトケミストリー
化学動力学化学動力学
スペクトロスコーピーは,スペクトロスコーピーを用います.

背景:

水性窒素イオン (NO3-) は,様々な環境および生物学的システムにおいて重要な成分である.
その光化学的振る舞いを理解することは,その運命と影響を評価するために不可欠です.

研究の目的:

200 nmの紫外線照射による水性窒素イオンの主要な光化学反応を調査する.
窒素光分解に含まれる過渡種と反応経路を特徴付けるために.

主な方法:

フェムトセカンド一時吸収スペクトロスコピーを用いて,194~388 nmの範囲の反応を検出した.
高時間解像度の測定により,短命の光製品が特徴付けられました.

主要な成果:

主要な光産物はペロキシニート (48%) のシス同位体である.
興奮した窒素イオンの有意な部分 (44%) は2ps以内に基本状態にリラックスします.
軽微な経路 (8%) は,NOとO2または関連種に解離することを含む.

結論:

200 nmの水性窒素の一次光分解は,シス-ペロキシニート形成によって支配されています.
NO2とNO2の不在は,以前の研究でその形成が二次的,より長い時間スケールの反応によって起こることを示唆しています.

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