Ciborowski Bartosz, Vacher Morgane
Nantes Université, CNRS, CEISAM UMR 6230, Nantes, France.
J Comput Chem. 2025 Jan 15;46(2):e70021. doi: 10.1002/jcc.70021.
Carbonyl complexes of metals with an α-diimine ligand exhibit both emission and ligand-selective photodissociation from MLCT states. Studying this photodissociative mechanism is challenging for experimental approaches due to an ultrafast femtosecond timescale and spectral overlap of multiple photoproducts. The photochemistry of a prototypical system is investigated with non-adiabatic dynamic simulations. Obtained 86 fs lifetime of the bright state and 13% quantum yield are in good agreement with experimental data. The present simulations suggest a ballistic mechanism of photodissociation, which is irrespective of the occupied electronic state. This is in contrast to the previously established mechanism of competitive intersystem crossing and dissociation. Selectivity of axial photodissociation is shown to be caused by the absence of an avoided crossing in the equatorial direction.
具有α-二亚胺配体的金属羰基配合物表现出从MLCT态的发射和配体选择性光解离。由于超快的飞秒时间尺度和多种光产物的光谱重叠，研究这种光解离机制对实验方法来说具有挑战性。利用非绝热动力学模拟研究了一个典型体系的光化学。得到的明亮态86飞秒的寿命和13%的量子产率与实验数据吻合良好。目前的模拟表明了一种与占据电子态无关的光解离弹道机制。这与先前确立的竞争性系间窜越和解离机制形成对比。轴向光解离的选择性被证明是由赤道方向不存在避免交叉所导致的。
