Struktur-Reaktivitäts-Beziehungen bei koordinativ ungesättigten Chelatkomplexen. VIII Neue Eisen(II)-Komplexe von dreizähnigen,dianionischen Schiffschen Basen mit [NO2]-Donorsatz

Structure Reactivity Correlations in Coordinatively Unsaturated Chelate Complexes. VIII. New Iron(II) Complexes of Tridentate Di-anionic Schiff Base Ligands with [NO₂]-Donor Set The synthesis of new iron(II) complexes of the type 3 is described. The complexes have been isolated as red or reddish brown adducts with the solvent (MeOH) and with additional bases (NH₃, pyridine), respectively. The compounds are extremely sensitive to air. All of them are high spin complexes. In absence of oxygen, the adducts cannot be converted into the solvent-free complexes by thermal treatment without decomposition of the chelate ligand. In the presence of moist air, however, the solvent molecules are removed quickly at room temperature. The oxidation results in black products which seem to be hydroxo ( 3a , 3b ) or dinuclear μ-oxo ( 3c , 3d , 3f ) iron(III) derivatives. Their reduced magnetic moments (3,2 … 4,5 μ_b) point to antiferromagnetic interactions. The iron(II) complexes react with iodine to form black 1:1 derivatives which exhibit a slightly reduced paramagnetism.