A series of lanthanide germanate cluster organic frameworks.
Six new lanthanide (Ln) germanate cluster organic frameworks (LnGeCOFs) derived from {Ln8Ge12} cage cluster units {[Nd(pza)2(H2O)] [Nd8Ge12(μ3-O)24E12(pza)(H2O)12]}·3H2O (1), {[Dy(CH3COO)(CO3)(H2O)]2[Dy8Ge12(μ3-O)24E12(H2O)12]}·11H2O (2), {[TbGeE(HO)2O(pza) (H2O)]2[Tb8Ge12(μ3-O)24E12(H2O)6]}·18H2O (3), {[DyGeE(HO)2O(C3H5NO2)(H2O)]2[Dy8Ge12(μ3-O)24E12(H2O)8]}·8H2O (4), {[Tb(pca)2 (H2O)]3[Tb8Ge12(μ3-O)24E12(H2O)4]}·(OH)3·10H2O (5) and {[Dy(pza)2(H2O)][Dy(pza)2(H2O)2][Dy(pza)3(H2O)][Dy8Ge12(μ3-O)24E12(pza)(HCOO) (H2O)6]}·5H2O (6) have been hydrothermally synthesized and structurally characterized. Increasing the amount of the second ligands can induce not only the assembly from 1 to 5, 6 based on Ln oxides as the starting sources, but also the assembly from 2 to 3, 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 of 1-6. 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 and 6 are the first dysprosium incorporated organogermanates based on bis(carboxyethylgermanium)sesquioxide. 4 and 5 display very open framework structures with a solvent-accessible volume of 34.6% for 4 and 35.0% for 5. Moreover, the solid-state photoluminescence properties of 1, 3 and 5 have been investigated at room temperature and they exhibit the characteristic emission bands derived from Ln cations.
MOE Key Laboratory of Cluster Science, School of Chemistry, Beijing Institute of Technology, Beijing 100081, China. ygy@bit.edu.cn.
Lei-Lei
LL
Li
MOE Key Laboratory of Cluster Science, School of Chemistry, Beijing Institute of Technology, Beijing 100081, China. ygy@bit.edu.cn.
Rui
R
Pan
Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, China. zhaojunwei@henu.edu.cn.
Jun-Wei
JW
Zhao
MOE Key Laboratory of Cluster Science, School of Chemistry, Beijing Institute of Technology, Beijing 100081, China. ygy@bit.edu.cn.
Bai-Feng
BF
Yang
MOE Key Laboratory of Cluster Science, School of Chemistry, Beijing Institute of Technology, Beijing 100081, China. ygy@bit.edu.cn and Department of Chemistry, Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province, Shantou University, Shantou, Guangdong 515063, China.
Guo-Yu
GY
Yang