Severi Marco, Zerbetto Francesco
Department of Chemistry G. Ciamician, University of Bologna, Via F. Selmi 2, 40126 Bologna, Italy.
J Phys Chem Lett. 2023 Oct 12;14(40):9145-9149. doi: 10.1021/acs.jpclett.3c02081. Epub 2023 Oct 5.
The ground state conformational isomerization in polyenes is a symmetry allowed process. Its low energy barrier is governed by electron density transfer from the formal single bond that is rotated to the nearby formal double bonds. Along the reaction pathway, the transition state is therefore destabilized. The rules of polaritonic chemistry, i.e., chemistry in a nanocavity with reflecting windows, are barely beginning to be laid out. The standing electric field of the nanocavity couples strongly with the molecular wave function and modifies the potential energy curve in unexpected ways. A quantum electrodynamics approach, applied to the torsional degree of freedom of the central bond of butadiene, shows that formation of the polariton mixes the σ-π frameworks thereby stabilizing/destabilizing the planar, reactant-like conformations. The values of the fundamental mode of the cavity field used in the absence of the cavity do not trigger this mechanism.
多烯中的基态构象异构化是一个对称性允许的过程。其低能垒由从旋转的形式单键向附近形式双键的电子密度转移所决定。因此，沿着反应路径，过渡态是不稳定的。极化子化学的规则，即在具有反射窗口的纳米腔中的化学，才刚刚开始被阐述。纳米腔的驻立电场与分子波函数强烈耦合，并以意想不到的方式修改势能曲线。将量子电动力学方法应用于丁二烯中心键的扭转自由度，结果表明极化子的形成混合了σ-π框架，从而稳定/不稳定平面的、类似反应物的构象。在没有腔的情况下使用的腔场基模的值不会触发这种机制。
