H+, Na+ and K+ modulated lanthanide luminescent switching of Tb(III) based cyclen aromatic diaza-crown ether conjugates in water

the cyclen based aromatic diaza-15-crown-5 and 18-crown-6 ether conjugates 1Tb–4Tb were designed as luminescent switches for sodium and potassium where the delayed Tb(III) Remission, occurring as line-like emission bands between 490–622 nm, was switched on upon recognition of these ions in pH 7.4 buffered water solution.