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)(H 2 O) 2 ] n [ M = Mn ( 1 ), Ni ( 2 )], [Cu(PDA)(4,4′‐bpy)] n · 2 n H 2 O ( 3 ), [Ni(PDA)(Im) 2 (H 2 O) 2 ] n · n H 2 O ( 4 ), and [Cu(PDA)(Im) 2 ] n · 2 n H 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 chelate 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.