Pyrene-based simple new hetero bis amide pyridinium salt for selective sensing of benzoate and hydrogen sulphate

A new pyrene-based hetero bis amide pyridinium salt 1 has been designed and synthesised. The hetero bis amide salt 1 selectively recognises benzoate over a range of aliphatic monocarboxylates in CHCl3 containing 2% CH3CN by showing concomitant increase in emission of pyrene. The flexible cleft of 1 also showed selective sensing of tetrahedral-shaped ion over ion. The recognition property of 1 was evaluated by 1H NMR, UV–vis and fluorescence studies.