Supramolecular assembly: Nanofibre whirlpools

The vortex in a stirring solution of a supramolecular fibres induces chirality in an originally a chiral system that can be switched by changing the direction of stirring. It has been shown that in a stirring solution of these a chiral fibres, a vortex, which is intrinsically chiral causes them to aggregate in a macroscopic chiral arrangement leads to the appearance of a circular dichorism (CD) signal. The molecular system is made up of a poryphyrin core with two bulky branched units and two carboxylic acid functional groups that are attached together. When the solution is stirred a CD signal is observed even after subtraction of the linear dichorism contribution. A similar effect is noticeable in a chemically unrelated system in a different solvent, proving the generality of the phenomenon, which provides a direct local measurement of how chirality can be expressed at a given point of time.