Titov Evgenii
University of Potsdam, Institute of Chemistry, Theoretical Chemistry, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany.
J Phys Chem Lett. 2024 Jul 25;15(29):7482-7488. doi: 10.1021/acs.jpclett.4c01608. Epub 2024 Jul 16.
Molecular exciton dynamics underlie energy and charge transfer processes in organic multichromophoric systems. A particularly interesting class of the latter is multiphotochromic systems made of molecules capable of photochemical transformations. Exciton dynamics in assemblies of photoswitches have been recently investigated using either the molecular exciton model or supermolecular configuration interaction (CI) singles, both approaches being based on a semiempirical Hamiltonian and combined with surface hopping molecular dynamics. Here, we study how inclusion of double excitations in nonadiabatic dynamics simulations affects exciton dynamics of multiazobenzenes, using trisazobenzenophane as an example. We find that both CI singles and CI singles and doubles yield virtually the same time scale of dynamical exciton localization, ∼50 fs for the studied multiazobenzene. However, inclusion of double excitations considerably affects the excited state lifetimes and isomerization quantum yields.
分子激子动力学是有机多发色团体系中能量和电荷转移过程的基础。后者中一类特别有趣的是由能够进行光化学转化的分子构成的多光致变色体系。最近，利用分子激子模型或超分子组态相互作用（CI）单激发态方法研究了光开关组件中的激子动力学，这两种方法均基于半经验哈密顿量，并与表面跳跃分子动力学相结合。在此，我们以三偶氮苯并环辛烷为例，研究在非绝热动力学模拟中包含双激发态如何影响多偶氮苯的激子动力学。我们发现，CI单激发态以及CI单激发态和双激发态给出的动态激子局域化时间尺度几乎相同，对于所研究的多偶氮苯约为50飞秒。然而，包含双激发态会显著影响激发态寿命和异构化量子产率。
