Reversible Anion Exchanges between the Layered Organic-Inorganic Hybridized Architectures: Syntheses and Structures of Manganese(II) and Copper(II) Complexes Containing Novel Tripodal Ligands

• Published in: Chemistry : a European journal 2003-08, Vol.9 (16), p.3965-3973
• Main Authors: Fan, Jian, Gan, Lu, Kawaguchi, Hiroyuki, Sun, Wei-Yin, Yu, Kai-Bei, Tang, Wen-Xia
• Format: Article
• Language: English
• Subjects: anion exchange; organic-inorganic hybrid composites; self-assembly; supramolecular chemistry; tripodal ligands
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.200204298

Six noninterpenetrating organic–inorganic hybridized coordination complexes, [Mn(3)2(H2O)2](ClO4)2⋅2 H2O (5), [Mn(3)2(H2O)2](NO3)2 (6), [Mn(3)2(N3)2]⋅2 H2O (7), [Cu(3)2(H2O)2](ClO4)2 (8), [Mn(4)2(H2O)(SO4)]⋅CH3OH⋅5 H2O (9) and [Mn(4)2](ClO4)2 (10) were obtained through self‐assembly of novel tripodal ligands, 1,3,5‐tris(1‐imidazolyl)benzene (3) and 1,3‐bis(1‐imidazolyl)‐5‐(imidazol‐1‐ylmethyl)benzene (4) with the corresponding metal salts, respectively. Their structures were determined by X‐ray crystallography. The results of structural analysis of complexes 5, 6, 7, and 8 with rigid ligand 3 indicate that their structures are mainly dependant on the nature of the organic ligand and geometric need of the metal ions, but not influenced greatly by the anions and metal ions. While in complexes 9 and 10, which contain the flexible ligand 4, the counteranion plays an important role in the formation of the frameworks. Entirely different structures of complexes 5 and 10 indicate that the organic ligands greatly affect the structures of assemblies. Furthermore, in complexes 5 and 6, the counteranions located between the cationic layers can be exchanged by other anions. Reversible anion exchanges between complexes 5 and 6 without destruction of the frameworks demonstrate that 5 and 6 can act as cationic layered materials for anion exchange, as determined by IR spectroscopy, elemental analyses, and X‐ray powder diffraction. Novel noninterpenetrating metal–organic frameworks are obtained from the self‐assembly of tripodal 1,3,5‐tris(1‐imidazolyl)benzene and 1,3‐bis(1‐imidazolyl)‐5‐(imidazol‐1‐ylmethyl)benzene ligands with manganese(II) and copper(II) salts. The 2D layered complexes display reversible anion‐exchange properties without destruction of the frameworks (see scheme). The results demonstrate that the 2D layered complexes can act as cationic layered materials for anion exchange.