Metal Complexes of a Novel Achiral Symmetric Pentadentate Ligand − Crystal Structures of Monohelical Zinc(II) and Cadmium(II) Complexes

Abstract

AbstractBy both electrochemical synthesis and a traditional chemical procedure the interaction of the pentadentate ligand 2,6‐bis{1‐[2‐(tosylamino)phenylimino]ethyl}pyridine (H2DAPATs), with MnII, FeII, CoII, NiII, CuII, ZnII and CdII gives rise to neutral mononuclear complexes that have been characterised by elemental analyses, FAB mass spectrometry, IR, 1H and COSY NMR spectroscopy and magnetic measurements, where appropriate. Recrystallisation of the zinc complex obtained electrochemically yielded single crystals of [Zn(DAPATs)] (1), while recrystallisation of cadmium complexes obtained by both techniques afforded the same structure, [Cd(DAPATs)(H2O)] (2). Both 1 and 2 are monohelical single‐stranded compounds with different coordination geometries. In the zinc complex, the metal ion assumes a distorted trigonal‐bipyramidal geometry involving the N5 atoms of the dianionic ligand. For cadmium complexes the metal ion is in a distorted pentagonal‐pyramidal environment, as the result of coordination to the N5 ligand donor set and an additional water molecule. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)