Nitrogen-containing porous carbon materials by twin polymerization

Abstract

The preparation of Si(OCH2 c C4H3NR)4 (5, R = Me; 6, R = H) by the reaction of 2-HOCH2- c C4H3NR (3, R = Me; 4, R = H) with SiCl4 in the ratio of 4:1 in the presence of NEt3 is described. The thermal behavior of twin monomers 5 and 6 was investigated by thermogravimetry and differential scanning calorimetry. Compound 6 shows with 93 °C the lowest polymerization temperature for twin monomers reported so far. In addition to the thermal-induced twin polymerization of 5 and 6, the acidic initiation and copolymerization with 2,2′-spiro-bi[4H-1,3,2-benzodioxasiline] was investigated. The resulting hybrid materials were characterized by 1H, 13C{1H}, and 29Si{1H} solid-state NMR spectroscopy confirming the transformation of the SiOCH2 moieties into CH2 groups enabling the formation of the respective polymers. These results are supported by HAADF-STEM studies, showing the typical microstructuring of a twin polymer. Furthermore, nitrogen-containing porous carbon materials with a surface area between 200 and 800 m2 g−1 and a nitrogen content of up to 9.1% were obtained. The chemical nature of the incorporated nitrogen was investigated by XPS spectroscopy, revealing that mostly pyrrolic nitrogen is observed, but also pyridinic species are present.