Helicene is a functional material with chirality caused by its characteristic helical geometry. The inversion of its helicity by external stimuli is a challenging task in the advanced control of the molecular chirality. This study fabricated a novel helical molecule, specifically a pentahelicene-analogue twisted aromatic hydrocarbon fused with a graphene nanoribbon, via on-surface synthesis using multiple precursors. Noncontact atomic force microscopy imaging with high spatial resolution confirmed the helicity of the reaction products. The helicity was geometrically converted by pushing a CO-terminated tip into the twisted framework, which is the first demonstration of helicity switching at the single-molecule scale.

中文翻译：

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石墨烯-纳米带稠合螺旋在 Au(111) 上的机械诱导单分子螺旋转换

Helicene 是一种功能材料，由于其特征性的螺旋几何形状而具有手性。在分子手性的高级控制中，通过外部刺激反转其螺旋度是一项具有挑战性的任务。这项研究通过使用多种前体的表面合成制造了一种新型螺旋分子，特别是与石墨烯纳米带融合的五螺旋烯类似物扭曲芳烃。具有高空间分辨率的非接触式原子力显微镜成像证实了反应产物的螺旋性。通过将一个 CO 末端的尖端推入扭曲的框架，螺旋度被几何转换，这是在单分子尺度上螺旋度转换的首次证明。