Organic oxidative reactions mediated by copper

Copper-Doped Nanoscale Covalent Organic Polymer for Augmented Photo/Chemodynamic Synergistic Therapy and Immunotherapy

Due to the specific tumor microenvironment (TME) and immunosuppressive state of cancer cells, conventional antitumor therapies face severe challenges, such as high rates of recurrence and metastasis. Herein, Cu-PPT nanoparticles were synthesized based on copper acetate, p-phenylenediamine, and 5,10,15,20-tetra-(4-aminophenyl)porphyrin via oxidative coupling reaction for the first time, and the resultant product was used for synergistic photothermal therapy (PTT), photodynamic therapy (PDT), and chemodynamic therapy (CDT). The polymer nanoparticles exhibited excellent photodynamic and photothermal effect with a photothermal conversion efficacy of 40.1% under 650 and 808 nm laser irradiation, respectively. Encapsulated Cu(I)/Cu(II) ions permitted Cu-PPT with glutathione (GSH) peroxidase-mimicking, catalase-mimicking, and Fenton-like activity to regulate TME. Depletion of overexpressed GSH would reduce antioxidant capacity, generated O₂ could relieve hypoxia for enhancing PDT, and hyperthermia from PTT could promote the yield of ·OH. This multifunctional nanosystem with cascade reactions could inhibit tumor growth and activate immune responses effectively. By further combining with antiprogrammed death-ligand 1 (anti-PD-L1) checkpoint blockade therapy, distant tumor growth and cancer metastasis were successfully suppressed.

Hexafluorosilicate anion in the formation of a coordination cage: anion competition

The construction of a coordination cage in a system of dual anions including hexafluorosilicate was investigated. Significant catalytic effects on catechol oxidation catalysis performance ranks among the most efficient yet recorded.

Mixed-valence Manganese Oxide Catalysed Oxidation of Benzyl Alcohol and Cyclohexanol in the Liquid Phase

Two types of mixed-valence manganese oxides were synthesised by a mechano-chemical process in the solid phase by chemical reaction of manganese(II) chloride and potassium permanganate at room temperature. The prepared catalysts were characterised by surface area and pore size, particle size, XRD analyses, SEM analyses and oxygen content measurements. These oxides were used as catalysts for oxidation of benzyl alcohol and cyclohexanol in the presence of solvent and also in solvent-free conditions using molecular oxygen as oxidant. The oxidation reactions were heterogeneous in nature where the catalysts were separated from the reaction mixture by simple filtration. Reaction took place in two steps according to the Langmuir–Hinshelwood mechanism. Benzyl alcohol/cyclohexanol and oxygen adsorb at the surface of the catalyst in the first step followed by reaction between adsorbed benzyl alcohol/cyclohexanol in second step. 69.8 kJ mol−1 and 140.8 kJ mol−1 were calculated as the activation energy for benzyl alcohol and cyclohexanol in n-octane as the solvent respectively, with values of 65.1 and 76 kJ mol−1 for benzyl alcohol and cyclohexanol in solvent-free conditions respectively.

Photocatalytic storing of O2 as H2O2 mediated by high surface area CuO. Evidence for a reductive-oxidative interfacial mechanism

CuO powders with a high specific surface area are shown to be able to produce H(2)O(2) in aqueous solution under simulated light irradiation. The highest rate of peroxide production was observed under mild experimental conditions using O(2) and a large surface area photocatalyst CuO irradiated with a solar simulator having light intensities between 60 and 90 mW/cm(2). The CuO employed had a specific surface area (SSA) of 64.8-70.1 m(2)/g and was prepared in a tubular furnace by controlled thermal decomposition of precipitated copper oxalate. The CuO particles produced were 1 mum cubes with primary particles around 15 nm. No peroxide was produced under the same conditions with commercial CuO, with SSA 200 times lower. The CuO synthesized during this work was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), specific surface area [Brunauer-Emmett-Teller (BET)], porosity, and X-ray photoelectron spectroscopy (XPS). From XPS, it was observed that only Cu(II) was present in the unused and used CuO. This indicates that the redox transient species involving other Cu oxidation states disappear very fast during the reaction, regenerating Cu(II) during H(2)O(2) production. Diverse experiments provided some evidence for the possible interfacial reaction mechanism leading to H(2)O(2), following the initial step of O(2)(-)(.) formation on the CuO surface under irradiation with photons, with energies exceeding the band gap of CuO. A photocatalyzed degradation of a concentrated 4-chlorophenol (4-CP) solution was observed under solar-simulated light in the presence of CuO.