Homotropic and heterotropic allosteric regulation of supramolecular chirality†
Allosteric regulation, a key biological phenomenon, has been demonstrated for controlling the supramolecular handedness of an artificial self-assembled system. Supramolecular assembly of perylene bisimide (PBI) functionalized with dipicolylethylenediamine (DPA) binding sites demonstrates a bistable chiral on–off state by the non-covalent interaction of adenosine phosphate guests. Both homotropic and heterotropic allosteric control of the supramolecular chirality in this otherwise helically dormant assembly could be achieved by the binding of chiral and achiral phosphate guests, respectively, hitherto unknown in a biomimetic system. Through detailed spectroscopic and morphological investigations the role of supramolecular reorganization in such an effect has been clearly established.