Iron and tin atom dynamics and hyperfine interactions of two structurally related half-sandwich complexes bearing a distannyl moiety

Two structurally related organometallic compounds containing both Fe and Sn have been examined by temperature-dependent Mössbauer effect (ME) spectroscopy to elucidate the bonding and lattice dynamics of the metal atoms. The iron atom parameters are not otherwise remarkable and the motion is essentially isotropic in the temperature range 90 < T < 250 K and in good agreement with the corresponding X-ray data. In the case of the Sn resonances, there is a marked difference in the QS parameter of the two differing tin atoms, and in addition there is a significant difference in the vibrational data extracted from the ME studies and the X-ray derived values. The vibrational amplitudes of all metal atoms are compared and discussed.