Visualization of bond rearrangements in acetylene using near single-cycle laser pulses

被引：29

作者：

Burger, Christian ^{[1
,2
]}

Kling, Nora G. ^{[1
]}

Siemering, Robert ^{[3
]}

Alnaser, Ali S. ^{[2
,4
]}

Bergues, Boris ^{[2
]}

Azzeer, Abdallah M. ^{[5
]}

Moshammer, Robert ^{[6
]}

de Vivie-Riedle, Regina ^{[3
]}

Kuebel, Matthias ^{[1
]}

Kling, Matthias F. ^{[1
,2
]}

机构：

[1] Ludwig Maximilians Univ Munchen, Dept Phys, D-85748 Garching, Germany

[2] Max Planck Inst Quantum Opt, D-85748 Garching, Germany

[3] Ludwig Maximilians Univ Munchen, Dept Chem & Biochem, D-81377 Munich, Germany

[4] Amer Univ Sharjah, Phys Dept, POB2666, Sharjah, U Arab Emirates

[5] King Saud Univ, Dept Phys & Astron, Riyadh 11451, Saudi Arabia

[6] Max Planck Inst Nucl Phys, D-69117 Heidelberg, Germany

来源：

FARADAY DISCUSSIONS | 2016年 / 194卷

关键词：

COULOMB EXPLOSION; VINYLIDENE; DICATION; STATES;

D O I：

10.1039/c6fd00082g

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The migration of hydrogen atoms resulting in the isomerization of hydrocarbons is an important process which can occur on ultrafast timescales. Here, we visualize the light-induced hydrogen migration of acetylene to vinylidene in an ionic state using two synchronized 4 fs intense laser pulses. The first pulse induces hydrogen migration, and the second is used for monitoring transient structural changes via Coulomb explosion imaging. Varying the time delay between the pulses reveals the migration dynamics with a time constant of 54 +/- 4 fs as observed in the H+ + H+ + CC+ channel. Due to the high temporal resolution, vibrational wave-packet motions along the CC-and CH-bonds are observed. Even though a maximum in isomerization yield for kinetic energy releases above 16 eV is measured, we find no indication for a backwards isomerization - in contrast to previous measurements. Here, we propose an alternative explanation for the maximum in isomerization yield, namely the surpassing of the transition state to the vinylidene configuration within the excited dication state.

引用

页码：495 / 508

页数：14