A novel hybrid organic/inorganic clay prepared by intercalation of a luminescent polyhedral oligomeric silsesquioxane (POSS) in a nanosized synthetic saponite clay was synthesized and characterized by a multidisciplinary approach including XRD, HRTEM, TGA and UV-Vis and photoluminescence spectroscopies. The luminescent POSS was obtained by linking a cyanine (IRIS3COOH) on the POSS cage functionalized with two amino groups (sample named IRIS3-POSS-NH2). One of the amino groups served for the inclusion in the saponite interlayer space. The final hybrid material (IRIS3-POSS-NH3/SAP), characterized by high quantum efficiency and improved thermal and photochemical stability with respect to the pure luminescent POSS and dye, was successfully tested as the luminescent layer in a hybrid light emitting diode (HLED) device.
A Site-isolated Lewis Acidic Aluminum and Brønsted Basic Amine Sites in Dimeric Silsesquioxane Cage as a Reusable Homogeneous Bifunctional Catalyst for One-pot Tandem Deacetalization/Deketalization-Knoevenagel Condensation Reactions
作者:Pushparaj Loganathan、Renjith S. Pillai、Abigail G. Jennifer、E. Varathan、M. Kesavan、Swaminathan Shanmugan
DOI:10.1039/d3nj00276d
日期:——
deacetalization-Knoevenagel condensation reactions and showed high efficiency (>90%) under optimized conditions (DMF, 0.3 mol% catalyst loading and 80 °C) with different reaction times. Furthermore, the bifunctional Al-POSS-NH2 catalyst was separated from the reaction mixture via the precipitation method by adding acetonitrile into the reaction mixture and reusing it for five consecutive cycles without
A novel luminescent polyhedral oligomeric silsesquioxane (POSS) containing in the structure a fluorescein derivative molecule and a carboxylic functionality, suitable to anchor different organic compounds (dyes, markers, drugs, contrast agents,…), was successfully synthesized and characterized in this manuscript by a multidisciplinary approach. An emission enhancement of the dye of ca. four times was found after reaction with POSS, rendering this new hybrid compound a promising contrast agent for optical imaging. In vitro tests on tumoral HeLa cells demonstrated that the luminescent POSS (namely POSS_F), here described, is able to be taken up in the cell cytosol by an efficient and selective process. Its high chemical versatility and peculiar properties could render this novel bifunctional POSS a molecular platform for biomedical applications.
A para-substituted bis(3-aminopropyl)hexaisobutyl-polyhedral oligomeric silsesquioxane (POSS) was successfully synthesized via a selective corner-opening reaction of 3-aminopropylheptaisobutyl-POSS and a subsequent corner-capping reaction. The selectivity of the corner-opening reaction was studied by density functional theory calculations. Polymerization of the POSS monomer with pyromellitic dianhydride resulted in a yellow, self-standing film.