Chelates of β-diketones. VI. Synthesis and characterization of dimeric dialkoxo-bridged iron(III) complexes with acetylacetone and 2,2,6,6-tetramethylheptane-3,5-dione (HDPM)

A series of compounds assigned the structure [L_2FeOR]_2 where L is the enolate of acetylacetone or dipivaloylmethane (HDPM) and R is CH_3, C_2H_5, and i-C_8H_7 has been prepared and characterized. They are obtained by the oxidation of ferrous compounds in alcoholic solutions containing free ligand and bases or directly from ferric compounds. These dimers are weakly antiferromagnetic (- J ≅ 10 cm^(-1)). Their infrared and optical spectroscopic properties are reported.