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

Abstract

New hybrid organicinorganic dyes based on an azidefunctionalized octasilsesquioxane (POSS) as 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 effect of the linkage group of BDP to the POSS unit and the degree of functionalization of this inorganic core on the optical properties by comparison with model dyes. The high fluorescence ability of the BDP dye is preserved in spite of the linked chain at its meso position and even after attaching one BDP to the POSS core. The laser action of the new dyes has been analyzed under transversal pumping at 532 nm in both liquid phase and when incorporated into solid polymeric matrices. The new hybrid dye exhibits high lasing efficiency of up to 56% with high photostability, with its laser output remaining at the initial value after 4×10 5 pump pulses in the same position of the sample at 30 Hz repetition rate. Nonetheless, the functionalization of the POSS core with eight fluorophores leads to dye aggregation, as quantum mechanics simulation reveals, worsening the optical properties and extinguishing the laser action. The new hybrid systems based on dye-linked POSS nanoparticles opens up the possibility of using these new photonic materials as alternative sources for optoelectronic devices, competing with dendronized or grafted polymers.

Controlled Click‐Assembly of Well‐Defined Hetero‐Bifunctional Cubic Silsesquioxanes and Their Application in Targeted Bioimaging

“…[31] Whereas TBTA (Scheme 3), a widely used accelerating copper(I)-ligand, did not have a significant effect on the outcome of diazide reactions, Finn and co-workers have described that some (benz-A C H T U N G T R E N N U N G imidazolylmethyl)amine ligands (e.g., A C H T U N G T R E N N U N G (BimC 4 A) 3 , Scheme 3) gave the monotriazole as the major product in the expected 2:1 mono-/bis-triazole statistical ratio in one example of conformationally rigid 1,3-diazide using a 1:1 diazide/alkyne reaction stoichiometry. [24] Based on the previous statistical calculations, we selected a rather conservative tenfold molar excess of 6 over alkyne 7 a to guarantee a very high statistical selectivity for the monofunctionalized product 7 (Table 1, entry 1). [21] The reaction could be easily followed by TLC by simple naked eye inspection, and affords a POSS derivative 7 (Scheme 1) labeled with a single fluorescent probe and seven additional reactive azide groups ready for further functionalization with any molecule of interest having a terminal alkynyl group.…”

“…[41] Both, MR and DC-SIGN bind to glycan patterns present on the surface of pathogens through multivalent carbohydrateprotein interactions. In addition, the covalent attach- ment of the BODIPY chromophore to the inorganic cage of POSS confers an improved photostability to the multivalent construct as we have described recently, [24,43] which is particularly important for the new imaging techniques developed in optical microscopy that require high-laser-intensity irradiation. In addition, the covalent attach- ment of the BODIPY chromophore to the inorganic cage of POSS confers an improved photostability to the multivalent construct as we have described recently, [24,43] which is particularly important for the new imaging techniques developed in optical microscopy that require high-laser-intensity irradiation.…”

“…Readily available homo-octafunctionalized POSS (1-6) used for the preparation of diverse hybrid materials and bifunctional POSS derivatives (7-16) prepared from 6 in this work. [24] We now disclose in detail the synthetic methodology and optimization studies that led to the hybrid dye 7 and the extension of the new methodology to the preparation of other bifunctional POSS (8-17, Scheme 1). To this end, we have followed a simple two-step strategy (Scheme 2), which involves the highly selective monofunctionalization of 6 by a controlled CuAAC reaction with a terminal functional alkyne followed by the subsequent CuAAC of the remaining seven azide groups with a second functional alkyne.…”

Multifunctional imine-POSS as uncommon 3D nanobuilding blocks for supramolecular hybrid materials: synthesis, structural characterization, and properties

“…Cubic silsesquioxanes constitute a group of organosilicon compounds with the chemical formula (RSiO 3/2 ) 8 (where R is H, alkyl, aryl, etc.). [15][16][17][18] Phthalimide and o-sulfobenzimide-functionalized silsesquioxanes have been found to be promising materials for the further functionalization of other nitrogen-based POSS. Covalently bonded organic arms make reactive functionalities suitable for polymerization or grafting.…”

Highly untangled multiwalled carbon nanotube@polyhedral oligomeric silsesquioxane ionic hybrids: Synthesis, characterization and nonlinear optical properties

“…Optical, light scattering and scanning electron microscopy (SEM) investigations on POSS@TPPS adduct demonstrated that the ''bulky'' POSSNMe 3 + acts as a highly dispersing agent toward the TPPS tetraanion, reducing its well known aggregation tendency, both in solution and in the solid state [17]. Hence, ionic self-assembly promoted by amphiphilic POSS-ILs turned out to be a useful alternative strategy to access, with respect to conventional covalent approaches [19][20][21], to novel POSS-multifunctional materials.…”