Synthesis and characterization of a monomeric and a dihydroxobridged dimeric complexes of iron(II) with a-benzilmonoxime

The reaction of a-benzilmonoxime(BMOH) with Fe(CH3COOh.4H20 in the presence ofCH3COONa as abase gives the mononuclear Fe(II) complex, Na[Fe(BMOhJ(I). Treatment of1 with a methanolic solution ofNaOH at room temperature leads to a dinuclear Fe(II)-Fe(II) complex, NadFe(BMO)20HJ2 (2). Thecomplexes were characterized on the basis oftheir elemental analysis, Mass, IR and electronic spectra. TheIR studies were useful in assigning the coordination mode ofthe benzilmonoxime ligand to the iron metal. Inaddition, the presence of a hydroxo-bridge in the dimeric complex 2 is inferred from the IR spectral studies.The electronic spectra ofthe complexes revealed two bands due to d-d transitions, and one band assignableto an oxygen (P;J- Fe(eg·) LMCT transition observed in both complexes. An additional charge-transfertransition, assignable to u-hydroxotp.i-« Fe(eg) was only observed for the dimeric complex 2.