Das Rituparna, Pandey Deepak K, Nimma Vinitha, P Madhusudhan, Bhardwaj Pranav, Chandravanshi Pooja, Shameem K M Muhammed, Singh Dheeraj K, Kushawaha Rajesh K
Physical Research Laboratory, Ahmedabad, India.
Department of Physics, Institute of Infrastructure Technology Research and Management, Ahmedabad, 380026, India.
Faraday Discuss. 2021 May 27;228(0):432-450. doi: 10.1039/d0fd00129e.
Strong-field ionization induces various complex phenomena like bond breaking, intramolecular hydrogen migration, and bond association in polyatomic molecules. The H-atom migration and bond formation in CH3OH induced by intense femtosecond laser pulses are investigated using a Velocity Map Imaging (VMI) spectrometer. Various laser parameters like intensity (1.5 × 1013 W cm-2-12.5 × 1013 W cm-2), pulse duration (29 fs and 195 fs), wavelength (800 nm and 1300 nm), and polarization (linear and circular) can serve as a quantum control for hydrogen migration and the yield of Hn+ (n = 1-3) ions which have been observed in this study. Further, in order to understand the ejection mechanism of the hydrogen molecular ions H2+ and H3+ from singly-ionized CH3OH, quantum chemical calculations were employed. The dissociation processes of CH3OH+ occurring by four dissociative channels to form CHO+ + H3, H3+ + CHO, CH2+ + H2O, and H2O+ + CH2 are studied. Using the combined approach of experiments and theory, we have successfully explained the mechanism of intramolecular hydrogen migration and predicted the dissociative channels of singly-ionized CH3OH.
强场电离会在多原子分子中引发各种复杂现象，如键断裂、分子内氢迁移和键缔合。利用速度成像（VMI）光谱仪研究了强飞秒激光脉冲诱导的CH3OH中的氢原子迁移和键形成。各种激光参数，如强度（1.5×1013 W cm-2 - 12.5×1013 W cm-2）、脉冲持续时间（29 fs和195 fs）、波长（800 nm和1300 nm）以及偏振（线性和圆偏振），可作为本研究中氢迁移和Hn+（n = 1 - 3）离子产率的量子控制手段。此外，为了理解单电离CH3OH中氢分子离子H2+和H3+的 ejection 机制，采用了量子化学计算。研究了CH3OH+通过四个解离通道发生解离形成CHO+ + H3、H3+ + CHO、CH2+ + H2O和H2O+ + CH2的过程。通过实验和理论相结合的方法，我们成功地解释了分子内氢迁移的机制，并预测了单电离CH3OH的解离通道。 （注：原文中“ejection”未翻译，可能是有拼写错误，推测可能是“emission”发射之意，若有误请根据实际情况调整）
