Institute of Physical and Theoretical Chemistry, University of Wurzburg, Am Hubland, D-97074 Wurzburg, Germany.
J Chem Phys. 2010 Aug 21;133(7):074304. doi: 10.1063/1.3469787.
The structure and dynamics of the C (2)A(2) electronically excited state of the benzyl radical, C(7)H(7), were investigated by nanosecond and femtosecond pump-probe photoionization. A free jet of benzyl radicals was generated by flash pyrolysis from the precursors 2-phenylethyl nitrite and toluene. Nanosecond multiphoton ionization spectra show a number of vibronic bands that are excited in the wavelength range of 290-310 nm. At excitation wavelengths of 305, 301, and 298 nm, rapid biexponential decay of the excited states was observed. Lifetimes at the C-state origin (305 nm excitation) are 400 fs and 4.5 ps. The lifetimes decrease with increasing excitation energy. The dynamics can be understood within a two-step internal conversion to the electronic ground state.
通过纳秒和飞秒泵浦探测光解，研究了苄基自由基 C(7)H(7) 的 C(2)A(2)电子激发态的结构和动力学。苄基自由基的自由射流通过前体 2-苯乙基亚硝酸盐和甲苯的闪光热解产生。纳秒多光子电离光谱显示了在 290-310nm 波长范围内激发的许多振子带。在 305、301 和 298nm 的激发波长下，观察到激发态的快速双指数衰减。在 C 态起源处（305nm 激发）的寿命为 400fs 和 4.5ps。寿命随激发能的增加而减小。动力学可以用两个步骤的内转换到电子基态来理解。
