An ionic Cu9Na4-phenylsilsesquioxane/bis(triphenylphosphine)iminium complex: synthesis, unique structure, and catalytic activity

The synthesis of a high nuclear (Cu9Na4) complex 1via the self-assembly of copper(II) phenylsilsesquioxane induced by complexation with bis(triphenylphosphine)iminium chloride (PPNCl) was successfully achieved. This complex, which includes two bis(triphenylphosphine)iminium PPN+ cations, represents the first example of a metallasilsesquioxane/phosphazene compound. The Cu9Na4-silsesquioxane cage demonstrates a nontrivial combination of two pairs of Si6-cyclic/Si4-acyclic silsesquioxane ligands and a fusion of two Si10Cu4Na2 fragments, combined via the central ninth copper ion. The catalytic efficacy of the copper(II) compound (1) was evaluated through the peroxidative oxidation of toluene using tert-butyl hydroperoxide (t-BuOOH) as the oxidant. The primary oxidation products were benzaldehyde (BAL), benzyl alcohol (BOL), and benzoic acid (BAC), with BAC being the predominant product, especially in acetonitrile (NCMe). The formation of cresols, indicating oxidation at the aromatic ring, was observed only in water and under microwave irradiation (MW) in NCMe. Remarkably, the highest total yield of 40.3% was achieved in water with an acidic additive at 80 °C, highlighting the crucial role of the acid additive in enhancing reaction efficiency and selectivity. This study underscores our copper(II) complex as a highly effective catalyst for toluene oxidation, demonstrating its significant potential for fine-tuning reaction parameters to optimize yields and selectivity. The unprecedented structure of the complex and its promising catalytic performance pave the way for further advancements in the fields of metallasilsesquioxane chemistry and catalysis.

Oxygen vacancy-rich CeO2 decorated with Cu3BiS3 nanoparticles: Outstanding visible-light photocatalytic performance towards tetracycline degradation

Recently, the degradation of antibiotics has attracted a lot of attention all over the world, because the accumulation of these recalcitrant compounds in the environment, and their entry into the food chain have severely affected on human health. Herein, oxygen vacancy-rich CeO2 was decorated with Cu3BiS3 nanoparticles to fabricate Z-scheme CeO2-x/Cu3BiS3 photocatalysts with a simple procedure. Intriguingly, photocatalytic ability of CeO2-x/Cu3BiS3 (30%) nanocomposite in the detoxification of tetracycline hydrochloride, cephalexin, azithromycin, and rhodamine B was elevated 31.3, 28.2, 45.2, and 10.1-folds as much as CeO2, and 5.19, 5.97, 32.2, and 4.69-folds compared with the CeO2-x photocatalyst, respectively. The admirable activity of CeO2-x/Cu3BiS3 (30%) nanocomposite was ascribed to the production of many charge carriers, efficacious segregation and transfer of charges, and improved textural features, which were confirmed by UV-vis DRS, EIS, photocurrent density, PL, and BET analyses. In addition, the TC degradation pathway was investigated with LC-MS analysis, and also the biocompatibility of the purified solution was displayed with wheat seed cultivation. Regarding outstanding activity and facile synthesis, the CeO2-x/Cu3BiS3 (30%) photocatalyst could be utilized for wastewater treatment.