3D Magnetically Ordered Open Supramolecular Architectures Based on Ferrimagnetic Cu/Adenine/Hydroxide Heptameric Wheels
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- 作者：Rubén Pérez-Aguirre ; Garikoitz Beobide ; Oscar Castillo ; Imanol de Pedro ; Antonio Luque ; Sonia Pérez-Yáñez ; Jesús Rodríguez Fernández ; Pascual Román
- 刊名：Inorganic Chemistry
- 出版年：2016
- 出版时间：August 1, 2016
- 年：2016
- 卷：55
- 期：15
- 页码：7755-7763
- 全文大小：717K
- 年卷期：0
- ISSN：1520-510X
文摘
The present work provides two new examples of supramolecular metal–organic frameworks consisting of three-dimensional extended noncovalent assemblies of wheel-shaped heptanuclear [Cu7(μ-H2O)6(μ3-OH)6(μ-adeninato-κN3:κN9)6]2+ entities. The heptanuclear entity consists of a central [Cu(OH)6]4– core connected to six additional copper(II) metal centers in a radial and planar arrangement through the hydroxides. It generates a wheel-shaped entity in which water molecules and μ–κN3:κN9 adeninato ligands bridge the peripheral copper atoms. The magnetic characterization indicates the central copper(II) center is anti-ferromagnetically coupled to external copper(II) centers, which are ferromagnetically coupled among them leading to an S = 5/2 ground state. The packing of these entities is sustained by π–π stacking interactions between the adenine nucleobases and by hydrogen bonds established among the hydroxide ligands, sulfate anions, and adenine nucleobases. The sum of both types of supramolecular interactions creates a rigid synthon that in combination with the rigidity of the heptameric entity generates an open supramolecular structure (40–50% of available space) in which additional sulfate and triethylammonium ions are located altogether with solvent molecules. These compounds represent an interesting example of materials combining both porosity and magnetic relevant features.