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

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• 作者：Pieter L.H. Verlooy ; Koen Robeyns ; Luc Van Meervelt ; Oleg I. Lebedev ; Gustaaf Van Tendeloo ; Johan A. Martens ; Christine E.A. Kirschhock
• 关键词：Cyclosilicate hydrate ; Hydrogen bonds ; Cubic silicate octamer ; Hexamethyleneimine ; Microporous material
• 刊名：Microporous and Mesoporous Materials
• 出版年：2010
• 出版时间：May 2010
• 年：2010
• 卷：130
• 期：1-3
• 页码：14-20
• 全文大小：981 K

文摘

A new cyclosilicate hydrate with composition (C₆H₁₄N)₄·[Si₈O₁₆(OH)₄]·12H₂O was crystallized and the structure determined by single-crystal X-ray diffraction. The structure, described by the tetragonal space group I4₁/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 hydrogen-bonded 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.