Designing a family of luminescent hybrid materials by 3-(triethoxysilyl)-propyl isocyanate grafted 2-hydroxynicotinic acid bridge molecules

The study concentrates on the syntheses of modified 2-hydroxynicotinic acid by 3-(triethoxysilyl)-propyl isocyanate (TESPIC) and the preparation of their corresponding organic-inorganic molecular-based hybrid material with the two components equipped with covalent bonds. The bridging unit is a derivative of 2-hydroxynicotinic acid which is utilized to coordinate to Tb3+, Eu3+ or Zn2+ and further occurred hydrolysis and polycondensation processes by functional triethoxysilyl groups. Ultraviolet absorption, phosphorescence spectra, and luminescence spectra were applied to characterize the photophysical properties of the obtained hybrid material and the above spectroscopic data present that the triplet energy of modified 2-hydroxynicotinic acid efficiently initiates the antenna effect and matches with the emissive energy level of metal ions. As a result, the intramolecular energy transfer process completed within these molecular-based hybrids and strong green or red emissions of Ln3+ have been obtained.

A new modification path was used to graft 2-hydroxynicotinic acid by 3-(triethoxysilyl)-propyl isocyanate to afford a bridge molecule through the hydrogen transfer addition reaction between them, subsequently a novel family of luminescent molecular based hybrid materials with chemical bond were constructed.Figure optionsDownload as PowerPoint slide