SU-21,a layered silicogermanate with organic amines covalently-bonded to germanium

摘要

A novel silicogermanate,[(Ge5.17Si1.83)O12(OH)2F2(NH2CH2CHNH2CH3)2] centre dot H2O (denoted as SU-21),was synthesized in the presence of 1,2-diaminopropane under hydro-/solvo-thermal conditions.SU-21 was characterised by scanning electron microscopy (SEM),wave-dispersive spectroscopy (WDS),CHN analysis,FTIR and in situ X-ray powder diffraction (XRPD).The crystal structure of SU-21 was determined by single crystal X-ray diffraction.SU-21 is built up from chains formed by the zeolite secondary building unit 4-1.The chains are further connected by pairs of GeO3FN2 octahedra to form a layer.The organic molecules 1,2-diaminopropane are present in the structure and the two nitrogen atoms from each 1,2-diaminopropane are covalently-bonded to the germanium atoms in GeO3FN2 octahedra.The layers are held together via hydrogen bonding.SU-21 is thermally stable up to 210 °C.