A piperazine derivative for fluorescence recognition of pyrene and colorimetric discrimination of Fe2+/Fe3+system

Abstract

A piperazine derivative, namely, (2‑hydroxy-naphthalen-1-ylmethylene)-[3-(4-{3-[(2‑hydroxy-naphthalen-1-ylmethylene)-amino]-propyl}-piperazin-1-yl)-propyl]-amine (L4) has been synthesized, structurally characterized by single crystal X-ray diffraction analysis and employed for selective fluorescence detection of pyrene along with colorimetric discrimination of Fe²⁺ and Fe³⁺. Fluorescence turn on process is attributed to the water assisted aggregation, in combination with π–π stacking of pyrene units. The lowest detection limit for pyrene is 2.5 × 10^–9 M whiles the association constant being 6.4 × 10⁴ M^–1.The colorimetric detection limits for Fe²⁺ and Fe³⁺ are 2.34 and 1.22 μM, respectively. L4 efficiently removes pyrene from real samples by solid phase extraction.