Silver(I) coordination polymer and nine-coordinated cadmium(II) complex with dimethyl pyridine-2,6-dicarboxylate supported by solid state and electrochemical studies

Abstract

Two complexes of dimethyl pyridine-2,6-dicarboxylate (L), [CdL3][CdI4] (1) and [Ag(L)NO3]n (2) were prepared and identified by elemental analysis, FT-IR, Raman and 1H NMR spectroscopy, cyclic voltammetry, and single-crystal X-ray diffraction. The crystal structure of 1 contains both complex cation and complex anion of the metal. Cadmium in [CdL3]2+, coordinated by three nitrogens and six oxygens, has a distorted tricapped trigonal prismatic geometry while [CdI4]2−, with four coordinated iodides, has a slightly distorted tetrahedral geometry. In the crystal structure of 2, silver has distorted tetrahedral geometry by coordination of nitrogen and three oxygens. One oxygen of nitrate in 2 bridges two silvers. Extension of these bridges forms a 1-D coordination polymer. Cyclic voltammetry of L reveals two reduction steps which are shifted after coordination in 1, while no significant shifts are observed in 2. Hydrogen bonds including C–HI, C–HO and C–HC and short interactions such as CI, , and O are compared with Cambridge Structural Database analogs . Two brief structural surveys on ligand coordination modes and silver polymers are also presented.