Rare earth (Eu3+, Tb3+) centered polymeric hybrids: composite assembly of radical addition polymerization and condensation reaction, physical characterization and photoluminescence

Abstract

A new functional polysilsesquioxanes linkage (abbreviated as VPBA-Si) is achieved through the hydrogen transfer nucleophilic addition reaction between 4-vinylphenylboronic acid and 3-(triethoxysilyl)-propylisocyanate (TEPIC). Three kinds of rare earth (Eu³⁺, Tb³⁺) centred hybrid materials are assembled with VPBA-Si and the copolymers, through the radical addition polymerization reaction between VPBA-Si, trans-styrylacetic acid and N-vinylphthalimid, the hydrolysis and copolycondensation reaction between the VPBA-Si unit and tetraethoxysilane (TEOS) and coordination reaction between ligand and rare-earth ions. In addition, another kind of rare earth (Eu³⁺, Tb³⁺) hybrid is constructed only through the addition polymerization reaction between trans-styrylacetic acid and vinyltrimethoxysilane without VPBA-Si. All these four series of hybrids and the precursors are characterized by NMR, FTIR, ultraviolet absorption, X-ray diffraction (XRD), scanning electron microscopy (SEM). In particular the photoluminescence properties of them are studied deeply, indicating that the hybrids with trans-styrylacetic acid show the most favourable characteristic luminescent properties (i.e. long lifetime and high quantum efficiency).