AI 中文总结
本研究通过扫描隧道显微镜结合光学光谱，以优于100 pm的精度调控单个酞菁附近分子的位置，揭示了分子间距离对其荧光的调控机制，还将该调控扩展至更大组装体，为分子系统光学性质的局域环境调控提供原子尺度见解。
AI 中文摘要
吸收和发射光的分子在显微镜、发光器件和光合作用中发挥核心作用。它们的荧光源于明确定义的辐射跃迁，该跃迁受电子态及其与核运动耦合的调控，而电子态和核运动又受局域环境影响。然而，发射体周围环境中可控的原子尺度变化的效应仍未被探索。在此，我们使用扫描隧道显微镜结合光学光谱，研究单个酞菁（phthalocyanine）在附近分子位置变化时的光学响应，该位置变化的控制精度优于100 pm。当分子间距离减小时，分子发射能量发生红移，其线轮廓也发生演化。在理论计算的支持下，我们解析了荧光变化的电子和核贡献。我们发现，红移源于两个分子的激发之间的相互作用，而线形变化则反映了分子转动自由度和非平衡动力学的改变。我们将这种调控扩展到更大的组装体中，其中一个分子可调控两个生色团的能量，模拟了光合系统中的环境调控。我们的研究为局域环境如何影响分子系统的光学性质提供了原子尺度的见解。
英文摘要
Molecules that absorb and emit light play a central role in microscopy, light-emitting devices and photosynthesis. Their fluorescence arises from well-defined radiative transitions that are governed by the electronic states and their coupling to the nuclear motion that are influenced by the local environment. Yet the effect of controlled atomic-scale variations in the emitter surroundings remains unexplored. Here, we use scanning tunneling microscopy combined with optical spectroscopy to investigate the optical response of a single phthalocyanine to the change in the position of a nearby molecule, controlled with precision better than 100 pm. Upon decreasing the intermolecular distance, the molecular emission energy redshifts and its line profile evolves. Supported by theoretical calculations, we disentangle the electronic and nuclear contributions to the changes in fluorescence. We find that the redshift originates from the interaction between the excitations of the two molecules, while the lineshape changes reflect modifications of the molecular rotational degree of freedom and non-equilibrium dynamics. We extend this control to larger assemblies, where one molecule tunes the energies of two chromophores, mimicking the environmental tuning in photosynthetic systems. Our study provides atomic-scale insight into how the local environment affects the optical properties of molecular systems.
