A family of double-layered coordination polymers containing Cd<sup>2+</sup>, N,O-chelating ligands, and bridging SCN<sup>−</sup> and Cl<sup>−</sup>

<div><p>The syntheses, structures, and characterization (IR, TGA/DTA) of a family of layered coordination polymers containing Cd<sup>2+</sup>, bridging anions (SCN<sup>−</sup> and Cl<sup>−</sup>), and chelating C<sub>2</sub>H<sub>6</sub>N<sub>2</sub>O<sub>2</sub> methyl carbazate (mc) and C<sub>3</sub>H<sub>8</sub>N<sub>2</sub>O<sub>2</sub> ethyl carbazate (ec) ligands are described, viz: Cd(SCN)<sub>2</sub>(C<sub>2</sub>H<sub>6</sub>N<sub>2</sub>O<sub>2</sub>), Cd(SCN)Cl(C<sub>2</sub>H<sub>6</sub>N<sub>2</sub>O<sub>2</sub>), Cd(SCN)<sub>2</sub>(C<sub>3</sub>H<sub>8</sub>N<sub>2</sub>O<sub>2</sub>), and Cd(SCN)Cl(C<sub>3</sub>H<sub>8</sub>N<sub>2</sub>O<sub>2</sub>). Single-crystal structures show them to contain distorted CdN<sub>3</sub>OS<sub>2</sub> (for the thiocyanate) and CdN<sub>2</sub>OCl<sub>2</sub>S (for the thiocyanate/chloride) octahedra, in which the mc and ec ligands adopt an N,O-bidentate coordination mode, and the four anions bridge adjacent metal ions, which leads to polymeric sheets built up from double-octahedral layers propagating in the (1 0 0) plane. The topological linkage of the metal ions, which is the same in each structure, can be described as a distorted hexagonal grid. The crystal structures are completed by weak N–H⋯O, N–H⋯N, N–H⋯Cl, and N–H⋯S hydrogen bonds, which all occur within the (1 0 0) polyhedral layers.</p></div>