Synthesis and properties of 1,3,5-benzene periodic mesoporous organosilica (PMO): Novel aromatic PMO with three point attachments and unique thermal transformations

Masakatsu Kuroki, Tewodros Asefa, Wesley Whitnal, Michal Kruk, Chiaki Yoshina-Ishii, Mietek Jaroniec, Geoffrey A. Ozin

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A new aromatic periodic mesoporous organosilica material containing benzene functional groups that are symmetrically integrated with three silicon atoms in an organosilica mesoporous framework is reported. The material has a high surface area, well-ordered mesoporous structure and thermally stable framework aromatic groups. The functional aromatic moieties were observed to undergo sequential thermal transformation from a three to two and then to a one point attachment within the framework upon continuous thermolysis under air before eventually being converted to periodic mesoporous silica devoid of aromatic groups at high temperatures and longer pyrolysis times. The mesoporosity of the material was characterized by powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), and nitrogen porosimetry, whereas the presence and transformation of the aromatic groups in the walls of the materials were characterized by solid-state NMR spectroscopy, mass spectrometry, and thermogravimetric analysis. The attachment of a benzene ring symmetrically onto three siloxanes of the framework was used advantageously as a cross-linker to enhance the thermal stability of the organic group. Some of these properties are investigated in comparison with other aromatic PMOs that have only two point attachments and an amorphous phenylsilica gel that has only one point attachment. The successful synthesis of the first aromatic PMO with its organic group attached within the framework through more than two points is an important step toward the synthesis of PMOs having organic groups with more complex and multiple attachments within the framework.

Original languageEnglish
Pages (from-to)13886-13895
Number of pages10
JournalJournal of the American Chemical Society
Issue number46
Publication statusPublished - Nov 20 2002


ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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