2D Crown Ether Cation Selectivity Simulator

Crown ethers are the textbook example of supramolecular molecular recognition: a ring of ether-oxygen donor atoms wraps around a metal cation whose size closely matches the ring's cavity, held together purely by non-covalent ion-dipole interactions. This 2D top-down simulator lets you choose a macrocycle from 12-crown-4 up to 21-crown-7 and a guest cation from Li⁺ to Cs⁺, then combines cavity-to-ion size complementarity, the cation's intrinsic electrostatic pull and a solvent-competition penalty into a binding free energy and an association constant, updated live as you change the solvent polarity or temperature slider — the same size-match, complementarity and solvent-effect principles the surrounding article on supramolecular chemistry describes. Drag the canvas to pan and scroll to zoom the ring view.