Synthesis and Twin Polymerization of Si(OCH2py)4 for Nitrogen‐containing Carbon Materials

Abstract

AbstractThe synthesis and twin polymerization (TP) of Si(OCH2py)4 (3 a, py=2‐cC5H4N; 3 b, py=3‐cC5H4N; 3 c, py=4‐cC5H4N) is discussed. The solid state structures of 3 b, c were confirmed by single‐crystal X‐ray crystallography showing non‐conventional H‐bonding, forming 2D chains (3 b) or 3D networks (3 c). Thermally induced TP of 3 a–c and their simultaneous polymerization with 2,2‘‐spiro‐bi[4H‐1,3,2‐benzodioxasiline] (4) is described. The resulting hybrid materials were characterized by 1H, 13C{1H}, and 29Si{1H} CP MAS NMR spectroscopy confirming the transformation of the SiOCH2 moieties into CH2 groups enabling the formation of the respective polymers. These results were supported by HAADF‐STEM studies, displaying micro‐structuring. Nitrogen‐containing porous carbon materials C_1–C_3 show surface areas of 1300 and 1700 m2 g−1, large pore volumes between 0.6–1.2 cm3 g−1, and nitrogen contents of up to 3.1 at‐%. X‐ray photoemission spectroscopy reveal that pyrrolic, pyridine, and pyridone nitrogen atoms are present. If equimolar amounts of 3 a–c and 4 are simultaneously polymerized in the presence of [Pd(OAc)2] (5), then the Pd nanoparticle‐decorated material Pd@C_3 (900 m2 g−1) was obtained, which showed k values of −0.083 and −0.066 min−1 in the reduction of methylene blue and methyl orange, proving the accessibility of the Pd NPs.