Selective and colorimetric fluoride anion chemosensor based on s-tetrazines

s-Tetrazine and their derivatives are found to be a class of selective and colorimetric chemosensors for fluoride anions. The supramolecular interaction (anion-π and charge/electron transfer) between fluoride ion and π-electron deficient tetrazines receptor could facilitate the F(-)-tetrazines electron transfer (ET) event that generates tetrazine˙(-) radical anion. Accordingly, the color of its solution changed from red to green. Furthermore, the recognition of F(-) in DMSO is tolerant to water (DMSO-H(2)O = 9:1, v/v) and shows excellent selectivity towards other anions, especially H(2)PO(4)(-) and OAc(-).