A series of lanthanide germanate cluster organic frameworks. Issue 30 (8th June 2016) - Li, Lei-Lei
Abstract : A series of lanthanide germanate cluster organic frameworks derived from {Ln8 Ge} cage cluster units were hydrothermally synthesized and structurally characterized. Abstract : Six new lanthanide (Ln) germanate cluster organic frameworks (LnGeCOFs) derived from {Ln8 Ge12 } cage cluster units {[Nd(pza)2 (H2 O)] [Nd8 Ge12 (μ3 -O)24 E12 (pza)(H2 O)12 ]}·3H2 O (1 ), {[Dy(CH3 COO)(CO3 )(H2 O)]2 [Dy8 Ge12 (μ3 -O)24 E12 (H2 O)12 ]}·11H2 O (2 ), {[TbGeE(HO)2 O(pza) (H2 O)]2 [Tb8 Ge12 (μ3 -O)24 E12 (H2 O)6 ]}·18H2 O (3 ), {[DyGeE(HO)2 O(C3 H5 NO2 )(H2 O)]2 [Dy8 Ge12 (μ3 -O)24 E12 (H2 O)8 ]}·8H2 O (4 ), {[Tb(pca)2 (H2 O)]3 [Tb8 Ge12 (μ3 -O)24 E12 (H2 O)4 ]}·(OH)3 ·10H2 O (5 ) and {[Dy(pza)2 (H2 O)][Dy(pza)2 (H2 O)2 ][Dy(pza)3 (H2 O)][Dy8 Ge12 (μ3 -O)24 E12 (pza)(HCOO) (H2 O)6 ]}·5H2 O (6 ) have been hydrothermally synthesized and structurally characterized. Increasing the amount of the second ligands can induce not only the assembly from1 to5, 6 based on Ln oxides as the starting sources, but also the assembly from2 to3, 4 based on Ln salts as the starting sources. The successful preparation of these LnGeCOFs suggests the importance of the second ligands in the structural construction of1–6 . To our knowledge, 1 is the first example that includes right- and left-handed helical chains among LnGeCOFs based on bis(carboxyethylgermanium)sesquioxide.2, 4 and6 are the first dysprosium incorporated organogermanates based on bis(carboxyethylgermanium)sesquioxide.4 and5 display very open framework structures with a solvent-accessible volume of 34.6% for4 and 35.0% for5 . Moreover, the solid-state photoluminescence properties of1, 3 and5 have been investigated at room temperature and they exhibit the characteristic emission bands derived from Ln cations.