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

Abstract Three new coordination polymers of {[Cd(bib) 3 ](ClO 4 ) 2 } n ( 1 ), [Cd(μ 2 -bip) 2 (N 3 ) 2 ] n ( 2 ) and [Cd(μ-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 CdX 2 (X = ClO 4 − , 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 CdN 6 octahedral geometry while, in the structure of 3 , the metal ion forms CdN 2 Cl 2 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 α-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⋯N and C H⋯Cl intermolecular hydrogen bonds, respectively. The complexes were characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction.