Photoactive binary and ternary lanthanide (Eu3+, Tb3+, Nd3+) hybrids with p-tert-butylcalix[4]arene derived Si–O linkages and polymers

Abstract

Through the reaction between the hydroxyl groups of p-tert-butylcalix[4]arene derivatives (Calix-Br, Calix-AC) and the isocyanate group of 3-(triethoxysilyl)-propyl isocyanate (TEPIC), two novel kinds of functional polysilsesquioxanes linkage precursors Calix-Br-Si and Calix-AC-Si have been synthesized. Then the binary and ternary hybrid materials are assembled with chemical bonds, which are composed of lanthanide ion centres (Eu(3+), Tb(3+), Nd(3+)), precursors Calix-Br-Si or Calix-AC-Si and the organic polymers [poly(4-vinylpyridine) (PVPD) or poly(methyl methacrylate) (PMMA)]. The composition and physical properties of these hybrids are characterized, especially comparing the photoluminescent characters. It is found that the hybrids with modified p-tert-butylcalix[4]arene derivative units show better photoluminescent properties than pure original p-tert-butylcalix[4]arene units or lanthanide complexes. Besides, introduction of polymer chain is favorable for the thermal stability, regular microstructure and luminescence of hybrid systems. Among the europium hybrids, the hybrids containing the polymer PMMA possesses the longest lifetime and highest quantum efficiency.