Supramolecular architecture of cadmium(II)–terephthalate complexes having a tridentate or tetradentate Schiff base as blocking coligand

Two new cadmium(II)–terephthalate complexes, ∞1{[Cd2(μ-terephthalate)2(L1)2]·9H2O}∞1{[Cd2(μ-terephthalate)2(L1)2]·9H2O} (1) and [{Cd(H2O)(L2)}2(μ-terephthalate)](terephthalate) · 10H2O (2), where L1 = (E)-N1,N1-diethyl-N2-(1-(pyridin-2-yl)ethylidene)ethane-1,2-diamine; L2 = N,N  ′-bis-(1-pyridin-2-yl-ethylidene)-ethane-1,2-diamine; terephthalate=benzene-1,4-dicarboxylate-O2C-C6H4-CO2-) have been synthesized by a conventional solution method. Characterization by single crystal X-ray crystallography shows that compound 1 is composed of 1-D polymeric zig-zag chains with distorted pentagonal-bipyramidal cadmium centers. Compound 2 consists of centrosymmetric dinuclear complexes with a distorted pentagonal-bipyramidal cadmium center in which one terephthalate ligand bridges the metal centres and another terephthalate anion with water of crystallization forms a H-bonding network.

Graphical abstractTwo new cadmium(II)–terephthalate complexes, one with the tridentate ligandN1,N1-diethyl-N2-(1-(pyridin-2-yl)ethylidene)ethane-1,2-diamine and other with the tetradentate ligandN,N′-bis-(1-pyridin-2-yl-ethylidene)-ethane-1,2-diamine, have been synthesized. The compound having the tridentate ligand is a 1D polymeric chain whereas the compound with the tetradentate ligand is a very rare type of dinuclear complex.Figure optionsDownload full-size imageDownload as PowerPoint slide