A series of Cadmium(II) complexes with 2-substituted terephthalate building block and N-Donor co-ligands: Structural diversity and fluorescence properties

Four new Cd(II) complexes have been prepared based on 1,2,4-trimellitic acid (H(3)tma) and monosodium 2-sulfoterephthalate (2-NaN(2)stp), formulated as [Cd-2(Htma)(2) (dpp)(2)(H2O)] (1), [Cd-3 (tma)(2) (2,4-bipy)(4)(H2O)(2)] (2), [Cd (2-Hstp) (2,2'-bipy)(2)]center dot 2H(2)O (3) and [Cd (2-Hstp) (2,4-bipy) (H2O)(2)] (4) (dpp = dipyrido [3,2 -a:2',3'-c] phenazine, 2,4-bipy = 2,4-bipyridine, 2,2'-bipy = 2,2'- bipyridine) by hydrothermal method. X-ray diffraction structural analyses show all these complexes crystallized in triclinic crystal system of Pt space group, but their structures are diverse. Complex 1 exhibits an infinite one-dimensional chain featuring the left- and right-handed stranded chains interweaved each other. For 2, the two-dimensional network is constructed by one-dimensional ladder-like chain linked by Cd2 ions. In complex 3, the cadmium ion is surrounded with one 2-Hstp(2-) anion and two 2,2'-bipy molecules. Complex 4 is also a discrete structure based on a metallic dieter unit. In all these complexes, the N-donor co-ligands take the important roles in the assembly of three-dimensional supramolecular structures. The fluorescence properties of complexes 1-4 could be assigned to the pi - pi* transition of organic ligands. (C) 2017 Elsevier B.V. All rights reserved.