Silica-based MCM-41-like mesoporous materials with high cobalt content (∞ g Si/Co g 23) have been synthesized through a one-pot surfactant-assisted procedure from aqueous solution using a cationic surfactant (CTMABr ) cetyltrimethylammonium bromide) as structural directing agent, and starting from molecular atrane complexes of Co and Si as inorganic hydrolytic precursors. This preparative technique allows optimizing the dispersion of the Co guest species in the silica walls. The mesoporous nature of the final materials is confirmed by XRD, TEM, and N 2 adsorption-desorption isotherms. They display unimodal and relatively narrow pore size distributions, whereas their pore array evolves from ordered hexagonal (H 0 ) to wormhole-like (W) as the Co content increases. A careful spectroscopic (UV-visible and NMR) and magnetic study of these materials shows that, regardless of the Si/Co ratio, Co atoms are organized in well-dispersed, uniform CoO nanodomains (ca. 3 nm) partially embedded within the silica walls. These materials, which show superparamagnetic behavior, can be referred to as mesoporous CoO-MCM-41 nanocomposites.

A diversity of zirconium-containing porous silicas of the MCM-41 type (Zr−MCM-41, ∞ ≥ Si/Zr ≥ 0.33) has been synthesized from aqueous solution using a cationic surfactant (CTABr = cetyltrimethylammonium bromide) as the structural directing agent, and starting from molecular atrane complexes of Zr and Si as precursors. Atrane inertness toward hydrolysis allows harmonization of the reactivity of the Zr and Si species, which in turn avoids subsequent phase segregation and results in chemically very homogeneous materials. Materials characterization by XRD, TEM, and N2 adsorption−desorption isotherms shows that all the prepared Zr−MCM-41 solids have high surface area and unimodal narrow pore size distribution, whereas their pore packing motives range from ordered hexagonal to wormhole-like arrays depending on the Zr content. The study of the local environment of the Zr atoms in these solids has been approached by means of spectroscopic techniques (IR, UV−vis, and NMR).