Photoluminescence of Bridged Polysilsesquioxanes Containing Urea Groups: Doping with Safranine-O to Generate Red-Light Emission.

M. L. GOMEZ, D. P. FASCE, R. J. J. WILLIAMS, H. A. MONTEJANO, C. M. PREVITALI

JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS

Wiley

Año: 2008 vol. 46 p. 289 - 296

0887-6266

Bridged polysilsesquioxanes containing urea groups (ureasils) exhibit a broad photoluminescent emission in the visible spectrum. For a particular bridged polysilsesquioxane synthesized by the hydrolytic condensation of a precursor prepared by reaction of 4,40-[1,3 phenylenebis-(1-methylethylidene)]bis(aniline) (BSA) with 3-(isocyanatepropyl)triethoxysilane (IPTES), we show that the broad photoluminescent band could be transformed into a relatively narrow emission band located in the red region of the spectra, by doping with Safranine-O. The spectral overlap between the host emission and the dye absorption generated an efficient energy transfer process (antenna effect). Absorption, emission, and triplet–triplet absorption spectra revealed an efficient dispersion of the dye in the ureasil as well as the presence of strong host-guest specific interactions.