FT-IR spectra and normal coordinate analysis of the [Cl2FeS2MoS2FeCl2]2− dianion

The FT-IR spectra of the [Cl2FeS2MoS2FeCl2]2− dianion were measured in the range 500 to 100 cm−1. A simplified general valence force field was used in a normal coordinate analysis. The calculated frequencies agree well with the observed values, with a mean deviation of less than 1.0%, thus confirming the assignments of the vibrational spectrum. Altogether 16 force constants, including stretching, bending, torsion and stretching-stretching interactions were obtained. The rationality and the reliability of the results were discussed.