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arXiv · 1705.00658

Geometrical optimization approach to isomerization: Models and limitations

Bo Y. Chang·Seokmin Shin·Volker Engel·Ignacio R. Sola
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Abstract

We study laser-driven isomerization reactions through an excited electronic state using the recently developed Geometrical Optimization procedure [J. Phys. Chem. Lett. 6, 1724 (2015)]. The goal is to analyze whether an initial wave packet in the ground state, with optimized amplitudes and phases, can be used to enhance the yield of the reaction at faster rates, exploring how the geometrical restrictions induced by the symmetry of the system impose limitations in the optimization procedure. As an example we model the isomerization in an oriented 2,2'-dimethyl biphenyl molecule with a simple quartic potential. Using long (picosecond) pulses we find that the isomerization can be achieved driven by a single pulse. The phase of the initial superposition state does not affect the yield. However, using short (femtosecond) pulses, one always needs a pair of pulses to force the reaction. High yields can only be obtained by optimizing both the initial state, and the wave packet prepared in the excited state, implying the well known pump-dump mechanism.

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Bo Y. Chang, Seokmin Shin, Volker Engel, Ignacio R. Sola. 2017-05-01. Geometrical optimization approach to isomerization: Models and limitations. https://doi.org/10.1021/acs.jpca.7b08767

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