Magnetic investigations of a two-dimensional coordination polymer with a three-dimensional supra­molecular framework: poly[[bis­[[mu]₂-1,4-bis­(1,2,4-triazol-1-yl)butane]­bis­(thio­cyanato-[kappa]N)cobalt(II)] dihydrate]

In the title mixed-ligand metal-organic polymeric complex, {[Co(NCS)₂(C₈H₁₂N₆)₂]·2H₂O}_n, the asymmetric unit contains a divalent Co^II cation, which sits on an inversion centre, two halves of two crystallographically distinct and centrosymmetric 1,4-bis­(1,2,4-triazol-1-yl)butane (BTB) ligands, one N-bound thio­cyanate ligand and one solvent water mol­ecule. The Co^II atom possesses a distorted {CoN₆} octa­hedral geometry, with the equatorial positions taken up by triazole N atoms from four different BTB ligands. The axial positions are filled by thio­cyanate N atoms. In the crystal, each Co^II atom is linked covalently to four others through the distal donors of the tethering BTB ligands, forming a neutral (4,4)-topology two-dimensional rhomboid grid layer motif, which is coincident with the (11) crystal planes. Magnetic investigations show that weak antiferromagnetic coupling exists between Co^II atoms in the complex.

A novel two-dimensional coordination polymer: poly[di­aqua­tetra-[mu]₂-chlorido-[[mu]₂-2,2'-(piperazine-1,4-di­ium-1,4-di­yl)di­acetate]­di­cadmium(II)]

In the crystal structure of the title two-dimensional metal-organic polymeric complex, [Cd₂Cl₄(C₈H₁₄N₂O₄)(H₂O)₂]_n, the asymmetric unit contains a crystallographically independent Cd^II cation, two chloride ligands, an aqua ligand and half a 2,2'-(piperazine-1,4-diium-1,4-di­yl)di­acetate (H₂PDA) ligand, the piperazine ring centroid of which is located on a crystallographic inversion centre. Each Cd^II centre is six-coordinated in an octa­hedral environment by an O atom from an H₂PDA ligand and an O atom from an aqua ligand in a trans disposition, and by four chloride ligands arranged in the plane perpendicular to the O-Cd-O axis. The complex forms a two-dimensional layer polymer containing [CdCl₂]_n chains, which are inter­connected into an extensive three-dimensional hydrogen-bonded network by C-H...O, C-H...Cl and O-H...O hydrogen bonds.