Cinnamate‐Functionalized Cage Silsesquioxanes as Photoreactive Nanobuilding Blocks

Yang

2015

Chemistry A European J

Self Cite

Mono- and octa-azobenzene-functionalized cage silsesquioxanes were easily synthesized by the reaction of 4-bromoazobenzene with monovinyl-substituted octasilsesquioxane and cubic octavinylsilsesquioxane through the Heck coupling reaction. Excited-state energies obtained from time-dependent density functional theory (TDDFT) and the CAM-B3LYP functional correlate very well with experimental trans-cis photoisomerization results from UV/Vis spectroscopy. These azobenzene-functionalized cages exhibit good thermal stability and are fluorescent with maximum emission at approximately 400 nm, making them potential materials for blue-light emission.

Section: Resultsmentioning

confidence: 99%

Azobenzene‐Functionalized Cage Silsesquioxanes as Inorganic–Organic Hybrid, Photoresponsive, Nanoscale, Building Blocks

Yang

2015

Chemistry A European J

Self Cite

“…On/off fluorescent switching and photostabilization via reversible cis‐trans isomerization have been also reported . Photo‐induced polymerization as well as cis‐trans photoisomerization studies in the presence of silsesquioxane nano‐cages have been reported as well.…”

Section: Introductionmentioning

confidence: 99%

Tuneable Emission of Polyhedral Oligomeric Silsesquioxane Based Nanostructures that Self‐Assemble in the Presence of Europium(III) Ions: Reversible trans‐to‐cis Isomerization

et al. 2019

Hybrid nanostructures with switchable and reversible “blue‐red‐green” emission were efficiently synthesized. These nanostructures comprise polyhedral oligomeric silsesquioxanes (POSS) that behave as a nanocage that can be functionalized with terpyridine‐based organic ligands, which can be easily complexed with europium (III) ions. The complexes were characterized by UV‐Vis and fluorescence spectroscopy and their stoichiometry was also confirmed by 1H NMR spectroscopy. In the presence of the Eu(III) ions, the octafunctionalized nanocages self‐assemble to form 3D architectures that display an intense red‐emission, especially in the solid state. The presence of an alkenyl group bridging the inorganic core to the organic moiety was employed to tune the emission properties by trans‐cis isomerization of the double bond. In the case of the octafunctionalized nanocages (O‐POSS), this isomerization was monitored in the presence of Eu(III) cations and was accompanied by an evident colour change from blue (trans‐O‐POSS) to red (Eu@trans‐O‐POSS) and finally to green (cis‐O‐POSS) as consequence of the release of the metal cations. This behaviour, together with the easy dispersion of the dry powder and the possibility of coating as a film in presence of small amounts of solvent, makes the emissive solid promising for applications in materials science.

“…A wide variety of functional groups, such as olefins, acrylates, phenols, fluoroalkyls, halides, amines, sulfhydryls, azides, nitriles, phosphines, carbazoles, imidazolium salts, azobenzenes, cinnamates, etc., can be used for this purpose [4,7]. Some examples of current applications of these functionalized POSS are: phenyl functionalized POSS are promising as gas separation membranes or as surface coatings for electronic or optical devices owing to their excellent thermal stability and electrical insulation [16,17]; vinyl-functionalized POSS can be grafted to or copolymerized with polymers because of the unsaturated groups on the surface [18]; amino-functionalized POSS hybrid composites show high reactivity and oxidation resistance [19,20]; and mercaptofunctionalized POSS can adsorb proteins or metal ions [21,22]. The functionalization of POSS is of great significance for the subsequent design and synthesis of intermediates and materials.…”

Section: Engineering Possmentioning

confidence: 99%

Use of Polyhedral Oligomeric Silsesquioxane (POSS) in Drug Delivery, Photodynamic Therapy and Bioimaging

2021

Polyhedral oligomeric silsesquioxanes (POSS) have attracted considerable attention in the design of novel organic-inorganic hybrid materials with high performance capabilities. Features such as their well-defined nanoscale structure, chemical tunability, and biocompatibility make POSS an ideal building block to fabricate hybrid materials for biomedical applications. This review highlights recent advances in the application of POSS-based hybrid materials, with particular emphasis on drug delivery, photodynamic therapy and bioimaging. The design and synthesis of POSS-based materials is described, along with the current methods for controlling their chemical functionalization for biomedical applications. We summarize the advantages of using POSS for several drug delivery applications. We also describe the current progress on using POSS-based materials to improve photodynamic therapies. The use of POSS for delivery of contrast agents or as a passivating agent for nanoprobes is also summarized. We envision that POSS-based hybrid materials have great potential for a variety of biomedical applications including drug delivery, photodynamic therapy and bioimaging.