Selective binding of lactate analogues over mandelate by a calix[4]arene-based zinc(II) salen receptor.

Two chiral zinc(II)-salen receptors based on calix[4]arene and phenyl frameworks were designed for carboxylate recognition. The calix[4]arene receptor binds lactate 3.2-3.8 times more strongly than the phenyl analogue and shows a preference for (R)-lactate. Its confined cavity enables selective binding of lactate analogues while discriminating against bulkier mandelate guests.