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

Abstract

Three new metal (II) complexes namely [Mn(3-ampy) 4(N 3) 2] ( 1), [Cd(3-ampy)(H 2O) 4] n (SO 4) n · (H 2O) 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)(H 2O) 4] 2+ cations and SO 4 2 - 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) Å] and two N atoms; the hetero nitrogen atoms of 3-ampy [Cd–N 2.262(3) Å], 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) Å]. 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 Cd 2N 2 through double μ-1,1 azide bridges, N, N′-3-ampy ligand and μ-1,3 azides generating a 3D network structure. There are hydrogen bonds of the type N–H⋯N between the NH 2 and azido groups consolidating the structure. The thermal properties of the three complexes have been recorded and discussed.