Assembly of three novel metal (II) complexes based on polycarboxylate and 1,10-phenanthroline ligands

With the principles of crystal engineering, three novel metal(II) complexes, [Cu-2(betd)(phen)(4)]center dot 15H(2)O (1), [Cd-4(betd)(2)(phen)(8)]center dot 28H(2)O (2) and {[Co-2(betd)(Phen)(2)(H2O)(2)]center dot 2H(2)O}(n) (3) (H(4)betd = bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic acid, phen = 1,10-phenanthroline) were synthesized and structurally characterized by elemental analyses, IR spectroscopy, single-crystal X-ray diffraction analyses, TGA, powder XRD and fluorescent measurements. Complex 1 is a binuclear structure, novel water tapes are observed to be encapsulated in the 3D open supramolecular architecture by hydrogen bond interactions. In 2, two pairs of Cd-II ions joined with two (betd)(4-) ions to form a cyclic tetranuclear structure. The neighboring tetranuclear units are linked into 2D network through pi center dot center dot center dot pi stacking interactions. Interestingly, the lattice H2O molecules are joined by strong hydrogen bond interactions generating a wavy water layer, which contacts the 2D network to form 3D supramolecular structure. 3 shows a 2D (4,4) grid network, which are assembled in an ABAB sequence to 3D supramolecular structures via pi center dot center dot center dot pi stacking interactions between two central phen ligands from two adjacent sheets and hydrogen bond interactions. (C) 2013 Elsevier B.V. All rights reserved.