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Z. Naturforsch. 2013,
68b, 797 – 803
doi:10.5560/ZNB.2013-2337
Loop-containing One-dimensional Metal-Organic Frameworks from Flexible Betaine Linkers and Zinc Salts by Controlled Synthesis
1 Laboratory of Advanced Materials, Fudan University, 2205 Songhu Road, Shanghai 200438, P. R. China
2 Department of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433, P. R. China
Reprint requests to Dr. Lijuan Zhang and Dr. Qiaowei Li. Tel: +86 21 51630231. E-mail:
zhanglijuan@fudan.edu.cn (L. Zhang), E-mail:
qwli@fudan.edu.cn (Q. Li)
Received February 1, 2013 / published online July 19, 2013
Three new metal-organic frameworks based on Zn2+ and 1,4-diazoniabicyclo[2.2.2]octane-1,4-diacetate (L) were synthesized and fully characterized by single-crystal X-ray diffraction and other methods. The linker L provides both positively charged quaternary ammonium centers and a flexible methylene chain, which brings conformational diversity to the system. The same reactants, and the same preparation procedures were used for the syntheses of ZnLCl2 (1), ZnL2(NO3)(OH)·(DMF)·(H2O) (2) and ZnL3(NO3)2(H2O) (3), to study the role of solvents and anions during the synthesis. All three MOFs show one-dimensional networks with different topologies. Closed loops with
different ring sizes could be found in 2 and 3 along the chain. Rings with 22 atoms were found in 2, while the smallest loop in 3 contains 44 atoms, including four linkers and four zinc atoms. Clearly, the solvent, stoichiometries of the reactants, and the anions had an impact on the formation of the three distinct network structures.
Key words: Metal-Organic Frameworks, Loop Motif, Solvothermal Synthesis, Double Betaine, Solvent Effects