A family of double-layered coordination polymers containing Cd²⁺, N,O-chelating ligands, and bridging SCN⁻ and Cl⁻

The syntheses, structures, and characterization (IR, TGA/DTA) of a family of layered coordination polymers containing Cd²⁺, bridging anions (SCN⁻ and Cl⁻), and chelating C₂H₆N₂O₂ methyl carbazate (mc) and C₃H₈N₂O₂ ethyl carbazate (ec) ligands are described, viz: Cd(SCN)₂(C₂H₆N₂O₂), Cd(SCN)Cl(C₂H₆N₂O₂), Cd(SCN)₂(C₃H₈N₂O₂), and Cd(SCN)Cl(C₃H₈N₂O₂). Single-crystal structures show them to contain distorted CdN₃OS₂ (for the thiocyanate) and CdN₂OCl₂S (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.