Molecular and crystal structure of the clathrochelate complex FeDm(3)(BF)(2)center dot C6H6 and parameters of its Fe-57 Mossbauer spectra

The molecular and crystal structure of the macrobicyclic complex FeDm(3)(BF )(2) . C6H6 was established by X-ray diffraction analysis at 138, 208, and 291 K. The X-ray diffraction data were compared with the Fe-57 Mossbauer sp ectral parameters of this complex in the temperature range of 135-290 K. A substantial disagreement between the experimental values of quadrupole spli tting and the corresponding values calculated based on the concept of parti al quadrupole splitting was attributed to the displacement of the Fe atom f rom the center of the cavity of the macrobicyclic ligand and to the distort ion of the axial symmetry of the electron density distribution about the me tal atom.