Secondary ligand-directed assembly of ZnII and CdII coordination architectures: From 1D to 3D compounds based on pyridine carboxylate ligands

To investigate the influence of spatial extended direction on the resulting structure, three new compounds have been synthesized by the reactions of ZnII or CdII salts and 3,5-bis(pyridin-4-ylmethoxy)benzoic acid (HL1) or 3,4-bis(pyridin-4-ylmethoxy)benzoic acid (HL2) with two rationally selected multicarboxylate ligands. Without a secondary ligand, an 1D ribbon structure [Zn(L1)2]·H2O (1) furnished, the hydrogen bonds extended the structure to a 2D layer. Employing 4,4′-biphenyldicarboxylic acid (H2bpdc), a 2D layer structure [Zn(L1)(bpdc)0.5] (2) resulted. The use of 1,3,5-benzenetricarboxylic acid (H3btc) led to a 3D compound [Cd2(L2)(btc)(H2O)] (3). It can be observed from the architectures of 1–3 that secondary ligands had great effects on the spatial connective fashions, resulting in the formation of various dimensional compounds.