Synthesis and characterization of the new cyclosilicate hydrate (hexamethyleneimine)4·[Si8O16(OH)4]·12H2O

✍ Scribed by Pieter L.H. Verlooy; Koen Robeyns; Luc Van Meervelt; Oleg I. Lebedev; Gustaaf Van Tendeloo; Johan A. Martens; Christine E.A. Kirschhock

• Book ID: 104057460
• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 982 KB
• Volume: 130
• Category: Article
• ISSN: 1387-1811
• DOI: 10.1016/j.micromeso.2009.10.006

✦ Synopsis

A new cyclosilicate hydrate with composition (C 6 H 14 N) 4 Á[Si 8 O 16 (OH) 4 ]Á12H 2 O was crystallized and the structure determined by single-crystal X-ray diffraction. The structure, described by the tetragonal space group I4 1 /a, with unit cell dimensions of a = 39.2150(2) Å and c = 14.1553(2) Å, contains columns of hydrogen-bonded cubic octamer silicate anions. The space between silicate columns holds hydrogenbonded water and protonated hexamethyleneimine molecules compensating the negative charge of the silicate. The crystal water can be removed resulting in a rearrangement of the columns into orthorhombic symmetry. Removal of the organic moiety causes amorphisation. Flash evacuation results in a new microporous material with pore volumes typical of a zeolite.