Dihydroacridine-functionalized pillar[5]arene with optical response towards alanine derivative

Aiming at the construction of novel macrocycle-based fluorescence probes, herein we have designed and synthesized a new functionalized pillar[5]arene (P[5]A-Ac) with the pillar[5]arene as the macrocyclic host and the dihydroacridine moiety as the fluorescence indicator. The stable host–guest complexing between P[5]A-Ac and alanine derivative (Ala-OEt) was confirmed by Job's plot, Uv–vis and ¹H NMR titration experiments. More importantly, remarkable fluorescence color change from blue towards light yellow was observed upon adding Ala-OEt to the solution of P[5]A-Ac, implying the dihydroacridine-functionalized pillar[5]arene could serve as a new fluorescence probe for the detection of alanine derivative.