Nanostructured aniline formaldehyde resin/polysilazane hybrid materials are produced by twin polymerization of 2,2′‐spirobi[3,4‐dihydro‐1H‐1,3,2‐benzodiazasiline] (1). An alternative synthetic concept for similar hybrid materials, the apparent twin polymerization, is employed by using the combination of the deficient twin monomer tetrakis(phenylamino)silane (2) with hexamethylenetetramine (HMTA). Both processes for the synthesis of polysilazane hybrid materials occur under volatilization of byproducts such as ammonia or aromatic nitrogen compounds. The thermal properties of the twin monomer 1 and the combination of 2/HMTA, respectively, are investigated by differential scanning calorimetry and thermogravimetric analysis. Aniline‐formaldehyde resin/polysilazane hybrid materials are characterized by solid state 13C‐ and 29Si‐NMR spectroscopy and transmission electron microscopy. The inorganic network remains hydrolyzable and can be functionalized after polymerization at temperatures below 500 °C due to residuary reactive Si−N bonds. Thermal treatment at 1100 °C leads to the formation of amorphous Si/C/N hybrid materials.

Front Cover: Nanostructured aniline formaldehyde resin/polysilazane hybrid materials are produced by twin polymerization of 2,2′‐spirobi[3,4‐dihydro‐1H‐1,3,2‐benzodiazasiline]. This is the first step to the formation of amorphous Si/C/N hybrid materials at higher temperatures. Further details can be found in the article by Lysann Kaβner, Anja Knoblauch, Andreas Seifert, Rolf‐Egbert Grützner, Gerhard Cox, Arno Lange, Szilard Csihony, Frank Simon, Susann Anders, Lothar Kroll, Mahfujur Rahaman, Dietrich Zahn, Lutz Mertens, Marcus Weber, Michael Mehring, and Stefan Spange* on page 2462.