Synthesis and characterization of two new silica socialites containing ethanolamine or ethylenediamine as guest species: [C 2H 7NO] 2[Si 6O 12] 2 and [C 2H 8N 2] 2[Si 6O 12] 2

Abstract

Two new clathrasils with sodalite structure were obtained using ethanolamine (EA) and ethylenediamine (ED), respectively, as structure-directing agents that also serve as solvents during the synthesis. Crystallization in the systems SiO 2 -Na 2 O-EA and SiO 2 -Na 2 O-ED, respectively, yields silica sodalites with each sodalite cage occupied by the corresponding organic molecule. The EA and ED molecules are the first amines that were found to direct the formation of silica sodalites. The two new silica sodalites were characterized by temperature-dependent powder X-ray diffraction, infrared and n.m.r. spectroscopy ( 1 H, 29 Si, 13 C), thermal analysis, and differential scanning calorimetry. Their properties are discussed and compared with ethylene glycol silica sodalite.