A porphyrin with two appended benzo-crown ethers in the form of a porphyrin-based molecular tweezer was synthesized and shown to bind the bipyridinium guests paraquat, diquat and Pt(bpy)(NH3)2 dications in several solvents. The conformations of the host molecule were shown to be solvent dependent. Lack of binding by a non-crown ether containing analogue demonstrated the necessity of the crown ether chains for the binding of guest molecules.
- crown ether
- molecular receptor