Synthesis, structure and characterization of two new Zn(II) and Cd(II) complexes with the bidentate ligand 2-[(2-aminoethyl)amino]ethanaminium (AEEA)

Abstract

Two new Zn(II) and Cd(II) complexes with the bidentate ligand 2-[(2-aminoethyl)amino]ethanaminium (AEEA), [ZnCl2(C4H14N3)]ClO4 (1) and [CdCl2(C4H14N3)]ClO4 (2), have been prepared and were characterized by single crystal X-ray diffraction, elemental analysis, CP–MAS-NMR and IR spectroscopies. The basic coordination patterns of the AEEA coordinated metal cations is highly distorted tetrahedral in (1) and distorted octahedral in (2). The crystal structure of (1) is characterized by ZnCl2N2 tetrahedra interconnected via N–H⋯Cl hydrogen bonds to form layers parallel to the (b, a+c) plane. In (2), the CdN2Cl4 entities form polymeric chains of edge-sharing octahedra extending along the a-axis direction. The crystal structures are stabilized by sets of hydrogen bonds, some of which are bi or trifurcated. The 13C and 15N CP–MAS NMR spectra are discussed and the vibrational absorption bands were identified by infrared spectroscopy.