Synthesis and characterization of three new Cd(II) coordination polymers with bidentate flexible ligands: Formation of 3D and 1D structures

Three new coordination polymers of {[Cd(bib)(3)](ClO4)(2)}(n) (1), [Cd(mu(2)-biP)(2)(N-3)(2)](n) (2) and [Cd(mu-bib(Me))Cl-2](n) (3) were prepared by using the neutral N-donor ligands 1,4-bis(imidazolyl)butane (bib), 1,3-bis(imidazolyl)propane (bip) and 1,4-bis(2-methylimidazolyl)butane (bib(Me)) and CdX2 (X= ClO4-, N-3(-) and Cl-). The results of the X-ray measurements demonstrate that in the crystal structure of 1 and 2 the cadmium(II) ion adopts CdN6 octahedral geometry while, in the structure of 3, the metal ion forms CdN2Cl2 tetrahedral geometry. In compound 1, six bib ligands are coordinated to one central cadmium(II) to form an open 3D 2-fold interpenetrating framework of the alpha-polonium (pcu) type topology, while in compound 2 and 3 the N-3(-) or Cl- groups are terminally bonded to the metal center and each linker compound (bip or bib(Me)) acts as bridging ligand connecting two metal ions to form a one-dimensional zig-zag chain. The adjacent 1D chains of complex 2 and 3 are further extended into a non-covalent 2D network structure by C-H center dot center dot center dot N and C-H center dot center dot center dot Cl intermolecular hydrogen bonds, respectively. The complexes were characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. (C) 2018 Elsevier B.V. All rights reserved.