Hydrothemal synthesis of zeolite-like zirconogermanates by the use of organic amines

A new class of microporous zirconogermanates, including FDZG-1 ((C ₄N₂H₁₂)[ZrGe₄O₁₀F ₂]), FDZG-2 ((NH₄)₂ZrGe₃O ₉), FDZG-3 ((C₂H₁₀N₂)·H ₂O·[ZrGe₃O₉]) and a known one, ASU-15 ((C₄N₂H₁₄)[ZrGe₂O₆F ₂]), have been synthesized by using cheap inorganic salt ZrO(NO ₃)₂·₂H₂O as a zircoium source and organic amines as the structure direct agents in hydrothermal condition. Their structures are all based on the principle whereby germanate units such as cyclic trigermanate, germanate chain and germanate layer, are bridged by ZrO₆ (or ZrO₄F₂) octahedrons to form frameworks. Non-framework species such as protonated organic amine cations, ammonium or water molecules fill the intra-crystalline pore space. FDZG-1 has a new three-dimensional (3D) open framework built up 1D 10-member ring (MR) channels. FDZG-2 has a new hexagonal structure (space group P63/m) with 3D framework composed of (4,6)-connected cage-like net FDZG-3 is also a novel zirconogermanate with a framework composed by odd rings, 3- and 7-MR. FDZG-1 and FDZG-3 have a relatively low framework density (FD) with a value of 13.5 and 13.4 T/1000 Å respectively.