Metal-ligand interactions in Fe(II)-dioxime complexes

The structural and bonding characteristics of Fe(II)-dioxime complexes of the type [Fe(dmgH)2L2] (where dmgH2 = dimethylglyoxime; L = 2-NH2-tiazole, pyridine, 4-methylpyridine, diethyl(phenyl)phosphine, diethyl(p-tolyl)phosphine) and [Fe(diox)3B(OR′)2] (where diox = dmg, cyclohexanedione dioximate; R′ = H, CH3, propyl) were investigated by means of quantum chemical computations. The equilibrium geometries and bonding properties were computed using the B3LYP exchange-correlation density functional in conjunction with a relativistic effective core potential and a polarized valence basis set for Fe, while 6-311G∗∗ basis sets for the other atoms. The characteristics of the metal-ligand interactions were elucidated by natural bond orbital analysis.