Monohelical Complexes of a Novel Asymmetric N4 Schiff Base: Unfamiliar Tetrahedral Environments of Manganese( II ) and Iron( II ) Helicates

The electrochemical reaction of the bis‐bidentate H2ABATs Schiff base [H2ABATs = N,N′‐bis(2‐tosylaminobenzylidene)‐2‐aminobenzylamine] with manganese, iron, cobalt, nickel, copper, zinc and cadmium was investigated. The reaction cell yields products of empirical formula M(ABATs). X‐ray diffraction studies show that [Mn(ABATs)]·0.75H2O (1), [Fe(ABATs)]·0.75H2O (2), [Ni(ABATs)]·0.75H2O (3), [Cu(ABATs)]·0.5H2O (4) and [Zn(ABATs)]·0.75H2O (5) are mononuclear distorted tetrahedral helical complexes in the solid state. Complexes 1 and 2 confirm the ability of this type of ligand to dictate the geometry around the metal centre, as is shown by the unfamiliar tetrahedral environments of manganese(II) and iron(II) ions in complexation with the Schiff bases. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)