trans-Bis(saccharinato)zinc and -cadmium Complexes with N-(2-Aminoethyl)piperazine: Synthesis, Crystal Structures and IR Spectra

Abstract

The reactions of N-(2-aminoethyl)piperazine (aeppz) with tetraaqua-bis(saccharinato)zinc(II) and -cadmium(II) in ethanol solution yield the new complexes trans-[Zn(sac) 2 (aeppz) 2 ] (1), and trans- [Cd(sac) 2 (aeppz) 2 ] (2) (sac = saccharinate), respectively. The complexes were characterized by elemental analyses, IR spectroscopy and X-ray crystallography. Both complexes 1 and 2 are mononuclear of Ci symmetry. The zinc(II) and cadmium(II) ions are coordinated by two neutral aeppz ligands and two sac anions in an elongated distorted octahedral environment. The aeppz ligand acts as a bidentate N, N’ donor through the central heterocyclic N atom and the N atom of the aminoethyl group, while the sac ligand is O-coordinated via the carbonyl O atom. The packing of the molecules in the crystals in both complexes is consolidated by arene π −π stacking interactions between the sac rings and by intermolecular hydrogen bonds involving the amine groups of aeppz and the sulfonyl oxygen atoms of the sac ligands