Goswami Tapas, Das Dipak K, Goswami Debabrata
Department of Chemistry, Indian Institute of Technology, Kanpur 208016, India.
Chem Phys Lett. 2013 Feb 12;558:1-7. doi: 10.1016/j.cplett.2012.10.054.
Dynamics of the chemical transformation of dicyclopentadiene into cyclopentadiene in a supersonic molecular beam is elucidated using femtosecond time-resolved degenerate pump-probe mass spectrometry. Control of this ultrafast chemical reaction is achieved by using linearly chirped frequency modulated pulses. We show that negatively chirped femtosecond laser pulses enhance the cyclopentadiene photo-product yield by an order of magnitude as compared to that of the unmodulated or the positively chirped pulses. This demonstrates that the phase structure of femtosecond laser pulse plays an important role in determining the outcome of a chemical reaction.
利用飞秒时间分辨简并泵浦-探测质谱法阐明了在超声分子束中二聚环戊二烯向环戊二烯的化学转化动力学。通过使用线性啁啾调频脉冲实现了对这种超快化学反应的控制。我们表明，与未调制或正啁啾脉冲相比，负啁啾飞秒激光脉冲可将环戊二烯光产物产率提高一个数量级。这表明飞秒激光脉冲的相位结构在决定化学反应结果方面起着重要作用。
