| Recently, the design and synthesis of coordination networks with porous structures continues to be a widespread growing field, its exploration is driven in part by the search for novel optical and electrosensitive materials as well as for new porous sorbents and catalysts. The selective uptake of specific heavy ions from aqueous solutions has also aroused intensive attention. Porous coordination frameworks, containing phosphates groups, sulfonate groups, and carboxylate groups could be served as potential candidates in heavy metal ion sorption by the result of their multiple coordination knots and many coordination modes. Meanwhile, ferrocene-based porous materials could also be widely used in the research of optical and electrochemical materials.In this paper, seven single crystals were obtained by the reactions of the 3-ferrocenylbenzenesulfonate (m-FcphSO3Na) and corresponding metal ions. Crystal structures of these complexes were conformed by single crystal X-ray diffraction and IR spectra also were used to characterize the chemical composition of these complexes. Additionally, their electrochemical and ion adsorption properties were also investigated.In presence of small organic ligands (4,4'-bpy, 1,3-bpp and 1,2-bpe), treatment of m-FcphSO3Na with Cd(NO3)2 or Zn(NO3)2 could afforded five polymers 1-5. Their chemical formula are [Cd(m-FcphSO3)2(4,4'-bpy)+2]n (1),[Zn2(m-FcphSO3)4(4,4'-bpy)4]n(2), [Cd(m-FcphSO3)2(bpp)2]n (3),[Zn(m-FcphSO3)2(bpp)2]n(4), [Cd(m-FcphSO3)2(bpe)2]n6(CH3OH)(5), respectively. Among these, crystal structures of 1,2,5 could be regarded as regular 2D grid-like framework. Despite that 3 and 4 have same bridging ligand, 1,3-bpp, their molecular structures are far different from the other because of their different central metal ions: for 3, cadmium and for 4, zinc. Polymer 3 possesses one-dimensional chain and polymer 4 is a two-dimensional framework. The electrochemical properties of polymers 1-4 and the m-FcphSO3Na have been investigated in the solution state. The experimental results show that the half-wave redox potentials of four complexes were a slightly higher than that of ligand ferrocenyl sulfonate. Further investigation of the electrochemical data revealed that the diffusion process controlled the electrode reactions of all complexes and the free sulfonate ligand. We also study the metal ion adsorption properties of polymer 1-4. From the experiment data, we can find that these materials could adsorb a large amount of Pb (II), Cu (II) ions.Aromatic sulfonate anion is poor ligands. Its coordination ability is similar to aqua molecules. Two inclusion complexes 6 and 7, formulated with[Cd(bbbm)(CH3OH)2(H2O)2(m-FcphSO3)2]n (6)(bbbm= 1,1'-(1,4-butanediyl)bis-1 H-benzimidazole) and{[Cd(btmbp)2(H2O)2(m-FcphSO3)2] (CH3OH)4(H2O)10}n (7)(btmbp=1,10-bis(triazol-1-ylmethyl) biphenyl), could achieved under aqua-methanol solution. They have the same coordination modes. The center metal ions are not directly coordinated by ferrocenyl sulfonates. To the contrary, they are respectively linked by bridging ligands bbbm and btmbp. The half-wave redox potentials of two complexes were slightly higher than that of sulfonate ligand because of the weak interaction in the structure. |
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