Copper(II)-Ethanolamine Triazine Complex on Chitosan-Functionalized Nanomaghemite for Catalytic Aerobic Oxidation of Benzylic Alcohols

Vitamin B5 copper conjugated triazine dendrimer improved the visible-light photocatalytic activity of TiO2 nanoparticles for aerobic homocoupling reactions

In this work, Cu-vitamin B5 (pantothenic acid) bonded to 2,4,6-trichloro-1,3,5-triazine produced a bioconjugated dendrimer giving rise to the visible-light photocatalytic activity of nanocrystalline TiO2. XPS spectra uncovered the coexistence of Cu(II)/Cu(I) oxidation states with a predominant contribution of Cu(I). The new heterogeneous bio-relevant Cu-photocatalyst (Cu(I) Cu(II) [PTAPA G2-B5] @TiO2) revealed a band gap value [Eg = (2.8 eV)] less than those of Cu free components [PTAPA G1-B5]@TiO2 (3.04) and [PTAPA G2-B5]@TiO2 (3.06) and particularly the bare TiO2 (3.15 eV). The reactions showed to be light-dependent with the best performance under room light bulbs. The photocatalytic efficiency of the as-prepared heterojunction photocatalyst was exploited in the aerobic Csp2-Csp2 homocoupling of phenylboronic acid and Csp-Csp homocoupling of phenyl acetylenes under visible-light irradiation to prepare structurally and electronically different biaryls. A radical pathway relying on the photogenerated e- and h+ and involving the Cu(I)-Cu(II) synergistic cooperation was postulated. The reusability and stability of the catalyst were verified by the recycling test, FT-IR spectra, and ICP-OES analysis.

Magnetic triazine-based dendrimer as a versatile nanocarrier for efficient antiviral drugs delivery

Nanoscale engineering is an efficient method for the treatment of multiple infectious diseases. Due to the controllable functionalities, surface properties, and internal cavities, dendrimer-based nanoparticles represent high performance in drug delivery, making their application attractive in pharmaceutical and medicinal chemistry. In this study, a dendritic nanostructure (Fe₃O₄@SiO₂@TAD-G3) was designed and fabricated by grafting a triazine-based dendrimer on a magnetic nanomaterial. The structure of synthesized hybrid nanostructure was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), energy-dispersive X-ray (EDX) spectroscopy, elemental mapping, scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and vibrating sample magnetometry (VSM). The prepared nanostructure (Fe₃O₄@SiO₂@TAD-G3) combines the unique properties of magnetic nanoparticles and a hyperbranched dendrimer for biomedical applications. Its dual nature and highly exposed active sites, could make the transportation of drugs to targeted sites of interest through the magnetic field. A study was conducted on model drugs loading (Favipiravir and Zidovudine) and in vitro release behaviour of Fe₃O₄@SiO₂@TAD-G3, which was monitored by ultraviolet spectroscopy. The dendritic nanostructure exhibited high drug-loading capacity for Favipiravir (63.2%) and Zidovudine (76.5%). About (90.8% and 80.2%) and (95.5% and 83.4%) of loaded Favipiravir and Zidovudine were released from Fe₃O₄@SiO₂@TAD-G3 at pH 1.5 and 6.8 respectively, within 600 min and at 37 °C. The initial fast release attributed to the drug molecules on the surface of nanostructure while the drugs incorporated deeply into the pores of the Fe₃O₄@SiO₂@TAD-G3 released with a delay. We proposed that Fe₃O₄@SiO₂@TAD-G3 could be tested as an effective carrier in the targeted (cellular or tissue) delivery of drugs. We think that the prepared nanostructure will not deposit in the liver and lungs due to the small size of the nanoparticles.