Synthesis and characterization of axial coordination cobalt(III) complexes containing chiral Salen ligands

Cobalt(III) complexes containing both optically active tetradentate Schiff base ligands, (SB = Salen, MeOSalen, t-Bu-Salen) with axial ligands (L) [Co(SB)L-2]ClO4 (L = imidazole (Im), 2-methylimidazole (2-MeIm), 1-methylimidazole (MeIm)) have been prepared and characterized. In addition, the crystal structures of [Co(Salen)(Melm)(2)]ClO4 (1c), [Co(MeOSalen)(MeIm)(2)]ClO4 (2c), and [Co(t-Bu-Salen)(MeIm)(2)]ClO4 (3c) have been determined by X-ray structure analysis. The properties of these hexacoordinate complexes, such as electronic absorption, circular dichroism spectra, and H-1 NMR spectra, have been studied. (C) 2003 Elsevier Science Ltd. All rights reserved.