Schlegel H Bernhard
Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States.
J Phys Chem A. 2023 Jul 27;127(29):6040-6050. doi: 10.1021/acs.jpca.3c02667. Epub 2023 Jul 17.
Strong field ionization of neutral iodoacetylene (HCCI) can produce a coherent superposition of the X and A cations and results in charge migration between the CC π orbital and the iodine π-type lone pair. This charge migration causes oscillations in the rate of strong field ionization of the cation to the dication that can be monitored using intense few-cycle probe pulses. The dynamics and strong field ionization of the coherent superposition the X and A states of HCCI have been modeled by time-dependent configuration interaction (TDCI) simulations. When the nuclei are allowed to move, the electronic wavefunctions need to be multiplied by vibrational wavefunctions. Nuclear motion has been modeled by vibrational packets moving on quadratic approximations to the potential energy surfaces for the X and A states of the cation. The overlap of the vibrational wavepackets decays in about 10-15 fs. Consequently, the oscillations in the strong field ionization decay on the same time scale. A revival of the vibrational overlap and in the oscillations of the strong field ionization is seen at 60-110 fs. TDCI simulations show that the decay and revival of the charge migration can be monitored by strong field ionization with intense 2- and 4-cycle linearly polarized 800 nm pulses. The revival is also seen with 7-cycle pulses.
中性碘乙炔（HCCI）的强场电离可以产生X阳离子和A阳离子的相干叠加，并导致电荷在CC π轨道和碘π型孤对之间迁移。这种电荷迁移会引起阳离子到双阳离子的强场电离速率的振荡，可使用强的少周期探测脉冲进行监测。HCCI的X态和A态的相干叠加的动力学和强场电离已通过含时组态相互作用（TDCI）模拟进行了建模。当允许原子核移动时，电子波函数需要乘以振动波函数。原子核运动已通过在阳离子X态和A态的势能面的二次近似上移动的振动包进行了建模。振动包的重叠在大约10 - 15飞秒内衰减。因此，强场电离中的振荡在相同的时间尺度上衰减。在60 - 110飞秒时可以看到振动重叠和强场电离振荡的复苏。TDCI模拟表明，电荷迁移的衰减和复苏可以通过用强的2周期和4周期线性偏振800纳米脉冲进行强场电离来监测。在7周期脉冲下也能看到复苏现象。
