Five-coordinated complexes of cadmium(II) and mercury(II) with tripod-like tetramines

Abstract

Some complexes of cadmium(II) and mercury(II) with the tetramines tris(2-aminoethyl)amine, tren, and tris(2-dimethylaminoethyl)amine, Me 6tren, are described. The anions are Cl −, Br −, I −, SCN −, NO 3 −, ClO 4 −, BPh 4 −. They were characterized by chemical analysis, electric conductivity, and vibrational spectroscopy. According to the nature of metal, amine, and anion a variety of complexes of different stoicheometries has been obtained. The cationic species are of the types [MX(Me 6tren)] + and [MX(tren)] + (X = Cl, Br, I, ClO 4, SCN) where the metal ions are five-coordinated. Metallic anionic species are [HgCl 4] 2−, [HgBr 4] 2−, and the novel ones [Cd 2I 6] 2−, [Hg 2I 6] 2−, and [Hg 2Br 6] 2−, all having tetrahedrally coordinated metal ions. The neutral complexes CdCl 2(Me 6tren) and CdBr 2(Me 6tren) are five-coordinated, with the amine acting as a tridentate ligand.