Molecular assembly and photoluminescence of novel rare earth/inorganic/polymeric hybrid materials with functional covalent linkages

In the context, organic polymeric precursor, polyethylene glycol (PEG) was firstly modified by inorganic component of 3-(triethoxysilyl)-propyl isocyanate (TEPIC) to form the inorganic/organic polymeric functional bridge precursor. Subsequently, the corresponding organic/inorganic molecular-based hybrids were assembled to behave the structural polymeric ligands with the two components equipped with covalent bonds. The coupling reagent part is a functional ureasils -NHC(=O)-O-group which is applied to coordinate to RE3+ and further formed Si-O backbones after hydrolysis and polycondensation processes. Furthermore, aromatic carboxylic acids (picolinic acid (HPIC), 2-chlorobenzoic acid (HCBA) and salicylic acid (HSAL)) were used as functional sensitized ligands to coordinate with RE3+(Eu3+, Tb3+ and Dy3+) and resulting in the quaternary rare earth/inorganic/organic polymeric hybrid materials with chemical bond (covalent bonds of -CO-NH- and Si-O, coordination bond of RE-O-C). Luminescence spectra were utilized to characterize the photophysical properties of the obtained hybrid material and the intramolecular energy transfer process took place within these molecular-based hybrids and characteristic emissions of RE3+ have been achieved. (c) 2006 Elsevier B.V. All rights reserved.