Synthesis and Characterization of Cobalt(II) and Copper(II) Tricyanomethanide (tcm) Complexes with 2,2′-Dipyridyl N,N′-Dioxide (dpdo) as Co-ligands: [Co(dpdo)(tcm)2], [Cu(dpdo)(tcm)2] and Cu(dpdo)2(tcm)2

Three new transition metal tricyanomethanide complexes [Co(dpdo)(tcm)(2)] (1), [Cu(dpdo)(tcm)(2)] (2) and Cu(dpdo)(2)(tcm)(2) (3) were synthesized and structurally characterized. In compound 1 each Co(II) ion is coordinated to four disorder tcm anions and one dpdo molecule to give a distorted octahedral geometry. In compound 2 each Cu(II) ion is surrounded by four tcm anions and one dpdo ligand to form a square bipyramidal geometry. Both compounds 1 and 2 display a mu(1,5)-tcm bridged infinite chain structure. Interestingly, in compound 3 coordination geometry around the central ion is square-planar, each Cu(II) ion is coordinated by two dpdo molecules to form a cationic part, the cationic parts is linked with the free tcm anionic parts via electrostatic attraction, leading to the formation of a mononuclear structure. Magnetic susceptibility measurement in the range 2-300 K indicates that there are antiferromagnetic couplings between adjacent metal ions in 1 (theta=-2.33 K, C=2.13 cm(3).mol(1).K) and 2 (J=-0.30, g=2.20) respectively.