Mr. Bermejo et al., A direct route to obtain manganese(III) complexes with a new class of asymmetrical Schiff base ligands, NEW J CHEM, 24(4), 2000, pp. 235-241
A new class of asymmetrically substituted Schiff base ligands has been synt
hesised incorporating hard amido donor atoms. The single crystal X-ray stru
cture of one of these ligands, H-3-amsal, has been determined [H-3-amsal =
3-aza-4-(2-hydroxyphenyl)-N-(2-hydroxyphenyl)but-3-enamide]. The structure
reveals the ligand to be suitable for use as an equatorially co-ordinating
ligand in octahedral complexes. A new route to obtaining manganese(III) com
plexes of these ligands, with high yield and purity, has been designed. Com
plexes of the form Mn-III(amsal-R) (H2O)(n) (n = 1-4) have been prepared by
the electrochemical oxidation of a manganese anode in an acetonitrile solu
tion of the ligands. The compounds have been characterised by elemental ana
lyses, IR and H-1 NMR spectroscopies, FAB mass spectrometry, magnetic measu
rements, Lambda(M) and cyclic voltammetry.