Search results for " Cluster chemistry"

showing 2 items of 2 documents

Real-Time Observation of “Soft” Magic-Size Clusters during Hydrolysis of the Model Metallodrug Bismuth Disalicylate

2021

International audience; Colloidal bismuth therapeutics have been used for hundreds of years, yet remain mysterious. Here we report an X-ray pair distribution function (PDF) study of the solvolysis of bismuth disalicylate, a model for the metallodrug bismuth subsalicylate (Pepto-Bismol). This reveals catalysis by traces of water, followed by multistep cluster growth. The ratio of the two major species, {Bi9O7} and {Bi38O44}, depends on exposure to air, time, and the solvent. The solution-phase cluster structures are of significantly higher symmetry in comparison to solid-state analogues, with reduced off-center Bi3+ displacements. This explains why such “magic-size” clusters can be both stab…

Cluster chemistrychemistry.chemical_element[CHIM.THER]Chemical Sciences/Medicinal Chemistry010402 general chemistry01 natural sciencesBiochemistryCatalysisBismuth subsalicylateBismuthlaw.inventionColloidColloid and Surface ChemistrylawCluster (physics)medicineOrganometallic Compounds[CHIM.COOR]Chemical Sciences/Coordination chemistryCrystallization010405 organic chemistryPair distribution functionGeneral ChemistrySalicylates0104 chemical sciences[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistryCrystallographychemistrySolvolysisCrystallization ; Group theory ; Bismuth ; Cluster chemistry ; Metal clustersBismuthmedicine.drug
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Improved Photocatalytic Activity of Polysiloxane TiO2 Composites by Thermally Induced Nanoparticle Bulk Clustering and Dye Adsorption

2021

Fine control of nanoparticle clustering within polymeric matrices can be tuned to enhance the physicochemical properties of the resulting composites, which are governed by the interplay of nanoparticle surface segregation and bulk clustering. To this aim, out-of-equilibrium strategies can be leveraged to program the multiscale organization of such systems. Here, we present experimental results indicating that bulk assembly of highly photoactive clusters of titanium dioxide nanoparticles within an in situ synthesized polysiloxane matrix can be thermally tuned. Remarkably, the controlled nanoparticle clustering results in improved degradation photocatalytic performances of the material under …

In situMaterials scienceNanoparticleSurfaces and InterfacesThermal treatmentCondensed Matter PhysicsMatrix (chemical analysis)chemistry.chemical_compoundchemistryCoating materials Oxides Composites Nanoparticles Cluster chemistryElectrochemistryPhotocatalysisDegradation (geology)Settore CHIM/01 - Chimica AnaliticaGeneral Materials ScienceComposite materialCluster analysisSpectroscopyMethylene blueSettore CHIM/02 - Chimica FisicaLangmuir
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