Novel chemically bonded Tb/Zn hybrid sphere particles: Molecular assembly, microstructure and photoluminescence

Abstract

4,5-Dihydroxy-1,3-benzenedisulfonic acid disodium salt (Tiferron, abbreviated as TF) is modified by 3-(triethoxysilyl)-propyl isocyanate (TESPIC) to afford a novel functional bridge intermediate (named as TFSi), which is used to coordinate with terbium or zinc ions and further introduced into silica matrices by Si–O bonds after hydrolysis and polycondensation processes. Subsequently, two luminescent chemically bonded organic–inorganic hybrid materials are assembled. Both of the two hybrids show the novel sphere-like microstructure except the Tb system that presents the smaller submicrometer sphere while Zn one shows the larger micrometer sphere, which may be ascribed to the different coordination behaviors of metal ions (Tb 3+ or Zn 2+). Green emission of Tb 3+ hybrids and violet-blue luminescence of Zn 2+ one have been achieved within the molecular-based hybrid materials. Besides, both Tb and Zn are introduced into the same hybrid systems through covalent Si–O bond, whose sphere particle size can be modified. Especially the photoluminescence can be enhanced, suggesting the intramolecular energy transfer that takes place between inert Zn 2+ and Tb 3+ within the chemically bonded hybrid systems.