Quadrupole hyperfine interaction in iron(III) dicarboxylic acid complexes

Mössbauer and infrared spectroscopic studies of a series of iron(III) complexes of dicarboxylic acids, maleic, malonic, succinic, glutaric, adipic, pimelic, suberic, azealic and sebacic have been carried out at room temperature. All complexes exhibit a quadrupole doublet with isomer shift () values in the range of 0.62 –0.72 mm·s^–1 (with respect to SNP) and quadrupole splitting, E_Q=0.53–0.74 mm· s^–1. It is observed that tris complexes are formed up to pimelic acid, while bis complexes are formed those for the other three acids. Isomer shift () values do not vary significantly but E_Q values show a somewhat regular trend. Magnetic moment data indicate high spin Fe(III) in octahedral geometry.