A high yield route to novel manganese(III) complexes

Neutral manganese(III) complexes have been prepared, with high yield and pu rity, by a modification of the Boucher synthesis, using asymmetrical Schiff base ligands. These ligands [H-3-amsal = 3-aza-4-(2-hydroxyphenyl)-N-(2-hy droxyphenyl)but-3-enamide], incorporating hard donor atoms, arc derived fro m the condensation of an amine precursor containing an amide group and subs tituted salicylaldehydes. The complexes are found to be of the form Mn-III (amsal-R)(H2O)(n) (n = 0.5,3) and have been characterised by various method s. Data point to octahedral geometry at the manganese atom.