Calix[4]arene with Lower‐Rim β‐Amino α,β‐Unsaturated Ketones Containing Bis‐Chelating Sites as a Highly Selective Fluorescence Turn‐On Chemosensor for Two Copper(II) Ions

摘要: We report herein the synthesis of a fluorescence turn-on chemosensor, 25,27-bis{N-[1-(4-{[4-amino-4-(1-naphthyl)-2-oxo-3-butenyl]oxy}phenyl)aminocarbonyl]methoxy}-26,28-dihydroxycalix[4]arene (3b), which is highly selective toward Cu 2+ . The intensity 3b was enhanced upon adding [Cu(ClO 4 ) 2 ], reached maximum with approximately equiv. but then started to decrease in at higher concentrations. Job plot experiments revealed 1:2 binding stoichiometry Based on 1 H NMR titration results, we infer that there are two possible sites for 3b: one lower-rim phenolic-OH and amide groups, second β-amino α,β-unsaturated ketone groups. It important note during complexation ions were reduced + by both phenolic OH amines ketones. Furthermore, control compounds 6 9b synthesized clarify 3b. By comparing constants 3b, 6, , found exhibited positive allosteric behavior coordination ions.