Schiff base as molecular tweezers for salicylaldehyde

We have synthesized a schiff base receptor, N,N′-ethylene-bis(salicylideneaminato) that exhibits the strong binding ability to salicylaldehyde as a guest. The binding characteristics of the interaction between the schiff base and salicylaldehyde have been monitored by 1H NMR spectroscopy. The reversible binding mechanism depending upon the solution pH has been monitored by 1H NMR spectroscopy during the acid titration reaction.