Molecular design and photophysical properties of acylamido side functionalized polysiloxanes with lanthanide ions as luminescent centers

Two series of acylamido side functionalized polysiloxanes were designed and synthesized from the modifications of amino silane with different acylating agents. They were complexed with lanthanide ions (Tb3+, Eu3+, Dy3+ and Sm3+) to obtain functionalized polysiloxane–lanthanide ions composite materials and exhibit the molecular assembly behaviors. The structures of products were characterized by Fourier transform infrared (FT-IR), 1H-NMR spectra and diffuse reflectance ultraviolet–visible spectra (DRUVS). Thermal stability was investigated by thermogravimetric analysis (TGA). Narrow-width red and green emissions of the functionalized polysiloxane–lanthanide ions complexes were recorded under the exposure to ultraviolet light. The results show that four kinds of lanthanide ions were all cooperated successfully with the functionalized polysiloxanes and an intra-molecular energy transfer process took place in these systems. Further investigations into the luminescence properties of the functionalized polysiloxane–lanthanide ions composite materials show that the triplet state energy of the benzoylamido side functionalized polysiloxane is more suitable for the emissive energy level of lanthanide ions than that of acetamido side functionalized polysiloxane. According to the rules between photophysical properties and diverse chromophoric conjugate groups, we could design and control the properties of the polysiloxane–lanthanide ion assembly complexes.