Transferring structural information from the nanoscale to the macroscale is a promising strategy for developing adaptive and dynamic materials. Here we demonstrate that the knotting and unknotting of a molecular strand can be used to control, and even invert, the handedness of a helical organization within a liquid crystal. An oligodentate tris(2,6-pyridinedicarboxamide) strand with six point-chiral centres folds into an overhand knot of single handedness upon coordination to lanthanide ions, both in isotropic solutions and in liquid crystals. In achiral liquid crystals, dopant knotted and unknotted strands induce supramolecular helical organizations of opposite handedness, with dynamic switching achievable through in situ knotting and unknotting events. Tying the molecular knot transmits information regarding asymmetry across length scales, from Euclidean point chirality (constitutional chirality) via molecular entanglement (conformation) to liquid-crystal (centimetre-scale) chirality. The magnitude of the effect induced by the tying of the molecular knots is similar to that famously used to rotate a glass rod on the surface of a liquid crystal by synthetic molecular motors.

将结构信息从纳米尺度转移到宏观尺度是开发自适应和动态材料的有前途的策略。在这里，我们证明了分子链的打结和未打结可用于控制，甚至反转液晶中螺旋结构的螺旋性。在各向同性溶液和液晶中，具有六个点手性中心的低齿三（2,6-吡啶二甲酰胺）链在与镧系元素离子配位时折叠成单手性的过手结。在非手性液晶中，掺杂的打结和未打结的链条会诱导出反手性的超分子螺旋结构，并通过原位打结和未打结的事件实现动态切换。捆扎分子结会在长度范围内传递有关不对称的信息，从欧几里得点手性（组成手性）到分子缠结（构象）再到液晶（厘米级）手性。通过打结分子所引起的效应的大小类似于众所周知的通过合成分子电动机旋转玻璃棒在液晶表面上的效应。