Syntheses, characterizations and structures of complexes of the types mononuclear [MII(tren)(dca)]ClO4 [M = Cu and Zn; tren = tris(2-aminoethyl)amine; dca = dicyanamide] and dinuclear [CdII 2(tren)2(dca)](ClO4)3: Variation of nuclearities and architectures with metal-ion templates

摘要

Two mononuclear [Cu(tren)(dca)]ClO4 (1) and [Zn(tren)(dca)]ClO4 (2) and one dinuclear [Cd2(tren)2(dca)]- (ClO4)3 (3) [tren = tris(2-aminoethyl)amine; dca = dicyanamide] compounds have been synthesized and characterized using spectroscopic, magnetic and X-ray crystallographic results. Complexes 1 and 2 adopt trigonal bipyramidal geometry with MN5 (M = Cu, Zn) chromophores coordinated through four N atoms of tren and one nitrile N atom of dca. In dinuclear 3, each pentacoordinated cadmium(II) center is in trigonal bipyramidal environment with a CdN5 chromophore coordinated once again by four N atoms of tren and the fifth position of each metal center is occupied by l1,5 bridged dicyanamide. In the long-range form, complexed cations and counter anions in 1 are engaged in N–HO, N–HN and C–HO hydrogen bondings resulting in a 2D sheet structure parallel to the ac-plane, and in 2 these hydrogen bonds are coupled with C–HN hydrogen bond leading to a 3D network structure. In 3, cooperative N–HO and C–HO hydrogen bonds are seen affording a 3D continuum.