Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA.
J Phys Chem A. 2011 Mar 10;115(9):1508-15. doi: 10.1021/jp1095322. Epub 2011 Feb 10.
The ultrafast dynamics of highly excited cis-stilbene (CS) in a molecular beam is explored using femtosecond time-resolved mass spectrometry and structure-sensitive photoelectron spectroscopy. cis-Stilbene is initially pumped by a 6 eV photon to the 7(1)B state and the reaction is followed by ionization with a time-delayed 3 eV probe pulse. Upon excitation, cis-stilbene rapidly decays to the 3(1)B state, where it undergoes a ring-closing reaction to form 4a,4b-dihydrophenanthrene (DHP). Whereas 14% of the ionized CS molecules dissociate one hydrogen atom to form hydrophenanthrene, the ionized DHP molecules completely dehydrogenate in the ion state to produce hydrophenanthrene and phenanthrene with a 1:1 ratio. We determined the lifetimes of the 7(1)B state and the 3(1)B state of CS to be 167 and 395 fs, respectively.
使用飞秒时间分辨质谱和结构敏感光电离谱研究了分子束中高激发顺式二苯乙烯（CS）的超快动力学。顺式二苯乙烯最初通过 6 eV 光子被泵浦到 7（1）B 态，并用延迟 3 eV 的探测脉冲进行电离来跟踪反应。激发后，顺式二苯乙烯迅速衰减到 3（1）B 态，在该态下它经历环闭合反应形成 4a,4b-二氢菲（DHP）。虽然 14%的离化 CS 分子解离一个氢原子形成氢化菲，但离化 DHP 分子在离子态下完全脱氢生成氢化菲和菲，比例为 1:1。我们确定 CS 的 7（1）B 态和 3（1）B 态的寿命分别为 167 和 395 fs。
