A wide family of pyridoxal thiosemicarbazone ferric complexes: Syntheses, structures and magnetic properties

This study reports the syntheses and the characterization of 12 ferric complexes of pyridoxal thiosemicarbazone. The richness of the coordination chemistry of this ligand is highlighted by the modulation of its charge from neutral H2L to anionic L-2, thus leading to a wide family of ferric compounds with charge varying from +3 to -1. The structures of complexes [Fe(HL)(2)]ClO4 center dot 2H(2)O and [Fe(HL)L] center dot 4.5H(2)O were solved and discussed with a particular attention brought to the intermolecular interactions occurring between the complexes. The investigation of magnetic properties of these compounds revealed that two of them are in the HS state at any temperature, whereas the others are in the LS state. These results are discussed in relation to the modulation of the electronic properties of the ligand. (c) 2008 Elsevier B.V. All rights reserved.