New metal(II) complexes containing monodentate and bridging 3-aminopyridine and azido ligands

Three new metal (II) complexes namely [Mn(3-ampy)(4)(N-3)(2)] (1), [Cd(3-ampy)(H2O)(4)](n)(SO4)n(.)(H2O)(n) (2) and [Cd(3-ampy)(N-3)(2)](n) (3) (3-ampy = 3-aminopyridine), have been synthesized and characterized by spectroscopic and crystallographic methods. The structure of 1 contains distorted octahedral Mn (II) atoms, monodentate 3-ampy and azide ligands. The structure of 2 consists of a packing of [Cd(3-ampy)(H2O)(4)](2+) cations and SO42- anions and lattice water molecules. The Cd (1) center in the cation is coordinated by four O atoms from aqua molecules [Cd-O from 2.261(3) to 2.409(2) Angstrom] and two N atoms; the hetero nitrogen atoms of 3-ampy [Cd-N 2.262(3) Angstrom], whereas Cd(2) atom is surrounded by four aqua molecules and two nitrogen atoms of two amino groups of 3-ampy molecules [Cd-N 2.378(3) Angstrom]. 3-Aminopyridine, therefore, acts as bidentate bridging ligands generating a 1D chain along [0, 1, -1]. Different hydrogen bonds are formed extending the structure to a 3D network. Complex 3 contains dimeric units Cd2N2 through double mu-1,1 azide bridges, N,N-3-ampy ligand and mu-1,3 azides generating a 3D network structure. There are hydrogen bonds of the type N-(HN)-N-... between the NH2 and azido groups consolidating the structure. The thermal properties of the three complexes have been recorded and discussed. (C) 2004 Elsevier Ltd. All rights reserved.