HYDROTHEMAL SYNTHESIS OF ZEOLITE-LIKE ZIRCONOGERMANATES BY THE USE OF ORGANIC AMINES

摘要

A new class of microporous zirconogermanates, including FDZG-1 ((C_4N_2H_(12))[ZrGe_4O_(10)F_2]), FDZG-2 ((NH_4)_2ZrGe_3O_9), FDZG-3 ((C_2H_(10)N_2)·H_2O·[ZrGe_3O_9]) and a known one, ASU-15 ((C_4N_2H_(14))[ZrGe_2O_6F_2]), have been synthesized by using cheap inorganic salt ZrO(NO_3)_2·2H_2O 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 ZrO_6 (or ZrO_4F_2) 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 A~3 respectively.