Click Assembly of Dye-Functionalized Octasilsesquioxanes for Highly Efficient and Photostable Photonic Systems

• Published in: Chemistry : a European journal Vol. 17; no. 47; pp. 13258 - 13268
• Main Authors: Pérez-Ojeda, M. Eugenia, Trastoy, Beatriz, López-Arbeloa, Íñigo, Bañuelos, Jorge, Costela, Ángel, García-Moreno, Inmaculada, Chiara, Jose Luis
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 18-11-2011; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Subjects: Alkynes; azides; Azides (inorganic); Azides (organic); Chemical compounds; Chemical synthesis; Chemistry; Chromophores; click chemistry; Cycloaddition; Dyes; dyes/pigments; Fluorescence; Fluorophores; Hybrid systems; hybrids; Laser outputs; Lasers; Liquid phases; Nanoparticles; Optical properties; Optoelectronic devices; Photonics; Polymers; Quantum mechanics; silsesquioxanes
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201100512

New hybrid organic–inorganic dyes based on an azide‐functionalized cubic octasilsesquioxane (POSS) as the inorganic part and a 4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene (BDP) chromophore as the organic component have been synthesized by copper(I)‐catalyzed 1,3‐dipolar cycloaddition of azides to alkynes. We have studied the effects of the linkage group of BDP to the POSS unit and the degree of functionalization of this inorganic core on the ensuing optical properties by comparison with model dyes. The high fluorescence of the BDP dye is preserved in spite of the linked chain at its meso position, even after attaching one BDP moiety to the POSS core. The laser action of the new dyes has been analyzed under transversal pumping at 532 nm in both the liquid phase and when incorporated into solid polymeric matrices. The monosubstituted new hybrid dye exhibits high lasing efficiency of up to 56 % with high photostability, with its laser output remaining at the initial value after 4×105 pump pulses in the same position of the sample at a repetition rate of 30 Hz. However, functionalization of the POSS core with eight fluorophores leads to dye aggregation, as quantum mechanical simulation has revealed, worsening the optical properties and extinguishing the laser action. The new hybrid systems based on dye‐linked POSS nanoparticles open up the possibility of using these new photonic materials as alternative sources for optoelectronic devices, competing with dendronized or grafted polymers.
Hybrid dyes: Fluorescently labeled mono‐ or octa‐substituted octasilsesquioxanes can be efficiently obtained from the corresponding octa‐azido silsesquioxane by click chemistry (see scheme). Attachment to the inorganic core significantly improves the laser performance of the dye in both the liquid phase and solid matrices.