Mössbauer spectra of iron(III) diketone complexes
The Mössbauer spectra of trisacetylacetonatoiron(III) and seven of its ligand-substituted derivatives have been recorded at liquid-nitrogen temperature. In many cases asymmetric peaks were obtained. All chemical shifts were close to 0·62 mm./sec.
A computer analysis showed quadrupole splittings ranging up to 0·75 mm./sec. The asymmetry of the two lines is interpreted in terms of electronic relaxation processes in the solid. From the relative broadening of the two absorption lines the sign of the electric-field gradient at the nucleus can be deduced.