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Novel silica nanoparticles exhibiting near-infrared (NIR) and dual NIR-visible emission were synthesized according to reverse microemulsion procedure through the encapsulation of Yb(III) complex with p-sulfonatothiacalix[4]arene (Yb) and [Ru(dipy)3]Cl2 (Ru) as NIR- and visible-emitting luminophores into silica matrix. The synthesis was carried out at various Yb:Ru molar ratio. The numbers of Ru and Yb complexes per one nanoparticle were calculated from both fluorimetric and inductively coupled plasma atomic emission spectroscopy data. The dynamic light scattering measurements of aqueous dispersions of Yb, Ru, and Ru−Yb nanoparticles elucidate the relationship between the complexes inserted into nanoparticles and their aqueous dispersity. The transmission electron microscopy images were used to measure the size of the nanoparticles. The atomic force microscopy images reveal the different aggregation morphology of Yb- and Ru-doped nanoparticles.

High‐valent cobaltIV‐bpy complex stabilized in silica matrix was detected as catalytically active form and intermediate in cobalt‐mediated oxidative C−H/NH cross‐coupling reaction. These CoIV species prepared by electrooxidation of CoIII(bpy)3‐doped silica nanoparticles (SNs) at relatively low anodic potentials have demonstrated high catalytic activity. Both size and architecture of the SNs are highlighted as the factors beyond the complex structure affecting its oxidation potential and catalytic efficiency. The factors have been optimized for the catalyst with high efficiency, easy separation and reusability for 7 times at least. The optimal nanocatalyst (1 mol%) provides 100 % conversion of reactants in a single step of ligand‐directed coupling of H2NTs with arenes under electrochemical regeneration conditions. The results emphasize both synthetic route for efficient embedding of CoIII(bpy)3 into silica support and the electrochemical generation of CoIV complexes as a facile route for developing the efficient nanocatalyst of oxidative functionalization. The observed reactivity has the potential in development of Co‐catalyzed coupling reactions.

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