Synthesis and characterization of 1D and 2D cadmium(II)-2,2′-bipyridine-N,N′-dioxide coordination polymers bridged by pseudohalides

Three cadmium(II) coordination polymesrs (CP) based on 2,2'-bipyridine-N,N'-dioxide (bipy-O2) as a coligand bridged by azido, thiocyanato and dicyanamido anions were synthesized. The complexes carena-[Cd(bipy-O2)(mu(1,3)-N-3)(2)] (1), catena-[Cd(bipy-O2)(mu(1,3)-NCS)(2)] (2) and catenci-[Cd(bipy-O2)(mu(1,5)-dca)(2)] (3), where dca=dicyanamide anion, NCNCN- were structurally characterized by X-ray single crystallography. The complexes display six-coordinated geometry around the central Cd(II) ion through the two oxygen atoms of the seven-membered chelating bipy-O2 molecule in cis conformation and four N-donor atoms of the doubly bridged end-on N-3(-) in complex 1 and in the dicyanamido complex 3 as well as the doubly bridged end-to-end through the terminal two N- and two S-donors in the corresponding thiocyanato compound 2. These arrangements led to the generation of 1D CP in the azido and thiocyanato complexes and a 2D CP in the dicyanamido complex 3. The luminescence and thermoanalytical properties of the complexes were also investigated.(C) 2018 Elsevier B.V. All rights reserved.