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

Abstract

Two new cadmium (II)–terephthalate complexes, _∞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.