Abstract:
It is well known that symmetry plays a key role in chemical reactivity. Here we explore its role in vibrational strong coupling (VSC) for a charge-transfer (CT) complexation reaction. By studying the trimethylated-benzene-I2 CT complex, we find that VSC induces large changes in the equilibrium constant KDA of the CT complex, reflecting modifications in the ΔG° value of the reaction. Furthermore, by tuning the microfluidic cavity modes to the different IR vibrations of the trimethylated benzene, ΔG° either increases or decreases depending only on the symmetry of the normal mode that is coupled. This result reveals the critical role of symmetry in VSC and, in turn, provides an explanation for why the magnitude of chemical changes induced by VSC are much greater than the Rabi splitting, that is, the energy perturbation caused by VSC. These findings further confirm that VSC is powerful and versatile tool for the molecular sciences.
摘要:
众所周知,对称性在化学反应性中起关键作用。在这里,我们探讨了其在电荷转移(CT)络合反应的振动强耦合(VSC)中的作用。通过研究三甲基化苯-I2CT络合物,我们发现VSC引起CT复合体平衡常数KDA的大变化,反映反应ΔG°值的变化。此外,通过将微流体腔模式调整为三甲基化苯的不同IR振动,ΔG°仅根据耦合的正常模式的对称性而增大或减小。这一结果揭示了对称性在VSC中的关键作用,反过来,解释了为什么VSC引起的化学变化的幅度远大于拉比分裂,也就是说,由VSC引起的能量扰动。这些发现进一步证实了VSC是分子科学的强大而通用的工具。