We have analyzed the great diversity of Fe-O-Fe angles, 140-180°, found in the X-ray structures of the (p-oxo)bis-[trichloroferrate(III)] dianion [Cl3FeOFeCl3]2- from both experimental and theoretical points of view. Theoretical calculations show that only the linear isomer is found as a minimum on the potential energy surface. Detailed analysis of the crystal packing indicates that the angular form is due to attractive intermolecular interactions. Analysis of a selected reduced set of the 45 crystal structures retrieved from the Cambridge Structural Database allowed us to classify the bending of the [Cl3FeOFeCl3]2- dianion in three categories, depending on the balance and strength of the intermolecular O⋯H-X contacts. A crystal diffraction study on the bis(benzyltrimethylammonium) salt has shown both bent (144.6°) and linear (180°) forms of the (μ-oxo)bis[trichloroferrate(III)] dianion. The magnetic susceptibility of this compound has been fitted by assuming two equally weighted contributions (Jang and Jlin) of the two forms, considering Jang - Jlin estimated by theoretical calculations. The obtained Jang and Jlin of -117 and -133 cm-1 respectively, agree well with B3LYP results. © Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
|Journal||Eur. J. Inorg. Chem.|
|Publication status||Published - 5 Dec 2003|
- (μ-Oxo)trichloroferrate dianion
- DFT calculations
- Magnetic properties
- Packing effects