Unusual coordination preferences of flexible tetradentate ligands and thiocyanate anions leads to <i>trans </i>nickel(II) and <i>cis </i>manganese(II) compounds

Abstract

The synthesis, characterisation and properties of two <i>trans </i>nickel(II) complexes with thiocyanate coordination. [Ni(L1)(NCS)₂] (<b>1</b>) and Ni(L2)(NCS)₂] (<b>2</b>) and comparison of the results with <i>cis</i>-[Mn(L1)(NCS)₂] (<b>3</b>) and <i>cis</i>-[Mn (L2)(NCS)₂] (<b>4</b>) (L1 and L2 = tetradentate ligands, derived from bis condensation between pyridine-2- carboxaldehyde and 1, 3-diaminopropanc and 2-benzoyl pyridine and 1,3-diaminopropane respectively) are described. The structures have been determined by single crystal X-ray diffraction studies. Study reveals that the nickel atom always produces <i>trans </i>isomer and manganese atom gives the <i>cis </i>isomer. Both metals are hexacoordinated with an unusual preferential binding of tetradentate ligands and thiocyanate anions.