Porous Magnesium Oxide by Twin Polymerization: From Hybrid Materials to Catalysis

Twin monomers [Mg(2-OCH₂-^cC₆H₄O)][L]_0.8 (2, L=diglyme) and [Mg(2-OCH₂-^cC₆H₄O)][L]_0.66 (3, L=tmeda) form by their thermal polymerization interpenetrating organic-inorganic hybrid materials in a straightforward manner. Carbonization (Ar) followed by calcination gave porous MgO (2: surface area 200 m²g^-1, 3: 400 m²g^-1), which showed in catalytic studies towards Meerwein-Ponndorf-Verley reductions excellent yields and complete conversions for cyclohexanone and benzaldehyde. However, with crotonaldehyde a mixture of C₄–C₈ compounds was obtained. When MgO was exposed to air then primarily crotyl alcohol was formed. The range of applications could be easily extended by twin polymerization of 3 in presence of [Cu-(O₂CCH₂O(CH₂CH₂O)₂Me)₂] (4) or [Ag(O₂CCH₂-^cC₄H₃S)(PPh₃)] (5), resulting in the formation of nanoparticle-decorated porous CuO@MgO or Ag@MgO materials, which showed high catalytic reactivity towards the reduction of methylene blue.