Preparation and characterization of 8-hydroxyquinoline-functionalized polysulfone and preliminary study on luminescence property of its complex with Al(III)

Abstract

8-Hydroxyquinoline aluminum complex-attached polysulfone was prepared via a polymer reaction and a coordination reaction, namely 8-hydroxyquinoline aluminum functionalization of polysulfone (PSF) was realized. 5-chloromethyl-8-hydroxyquinoline (CHQ) was first prepared through the chloromethylation reaction between 8-hydroxyquinoline (HQ) and chloromethylation reagent 1,4-bichloromethoxy-butane (BCMB). A polymer reaction, Friedel-Crafts alkylation reaction, was carried out between PSF and CHQ in the presence of Lewis catalyst SnCl4, and HQ was bonded onto the side chains of PSF, obtaining the modified polysulfone HQ-PSF. Then, the coordination reaction between HQ-PSF and 8-hydroxyquinoline aluminum complex AlQ2, which had two HQ ligands, was conducted, and the luminescence material AlQ3-PSF, in whose molecular structure 8-hydroxyquinoline aluminum complex AlQ3 is attached chemically onto the side chains of PSF, was achieved, namely, the AlQ3-containing PSF was successfully prepared. The chemical structures of HQ-PSF and AlQ3-PSF were fully characterized by FTIR, 1H NMR and the UV/vis absorption spectrum, and the luminescence performance of AlQ3-PSF was initially examined. In this work, the 8-hydroxyquinoline functionalization process of PSF was mainly investigated. The effects of the key factors on the Friedel-Crafts alkylation reaction, which occurs on the side chains of PSF macromolecules, were mainly researched, and the reaction mechanism was explored. The experimental results show that the Friedel-Crafts alkylation reaction between PSF and CHQ can proceed smoothly, and the suitable reaction conditions are as follows: a temperature of 70 °C, with N,N-dimethylformamide (DMF) as solvent, and using SnCl4 as a Lewis catalyst. The AlQ3-containing polysulfone, AlQ3-PSF, possesses the fluorescence-emission spectrum of AlQ3, and its luminescence performance is nearly identical with AlQ3 under the same concentration condition of the AlQ3 unit. Open image in new window