A Series of Transition Metal Coordination Polymers Bearing 1,4-Phenylenediacetate

The reactions of transition metal salts or hydroxide with 1,4-phenylenediacetic acid (H(2)PDA) in the presence of ancillary ligands 4,4'-bipyridine (4,4'-bpy) or imidazole (Im) produced five coordination polymers with the empirical formula [M(PDA)(4,4'-bPy)(H2O)(2)](n) [M = Mn (1), Ni (2)], [Cu(PDA)(4,4'-bPY)(n)center dot 2nH(2)O (3), [Ni(PDA)(Im)(2)(H2O)(2)](n)center dot nH(2)O (4), and [Cu(PDA)(Im)(2)](n)center dot 2nH(2)O (5). Their structures were determined by single-crystal X-ray diffraction analyses. The isomorphous 1 and 2 present a two-dimensional sheet constructed by two kinds of one-dimensional chains of -Ni-II-PDA(2-)-Ni-II- and -Ni-II-4,4'-bpy-Ni-II-. Compound 3 features dinuclear subunits, which are further connected by two PDA(2-) ligands and two 4,4'-bpy ligands along (001) and (011) directions, respectively, to build a two-dimensional sheet with the topology (4(2).6(7).8)(4(2).6) different from those of 1 and 2. Both 4 and 5 show one-dimensional chain structure. The difference of compound 4 and 5 is that the two carboxylato groups of PDA(2-) in 4 adopt monodentate coordination modes, whereas the two carboxylato groups of PDA(2-) in 5 dictate to the metal ions. Magnetic susceptibility data of 1 were measured. Magnetically, 1 presents a one-dimensional chain with a weak antiferromagnetic interaction (J = -0.064 cm(-1)) between the intrachain Mn-II atoms mediated by 4,4'-bpy.