Ferrocene Mossbauer absorption

Fig. 4-9. Mossbauer absorption spectrum of ferrocene at 4.2°K and a zero-G field. The velocity relative to iron in millimeters per second.

Other Papers.—Various iron species prepared by the vacuum pyrrolysis of acetyl-ferrocene-furfural resins at 400°C have been studied by Mossbauer spectroscopy. These consist of an amorphous glass-like carbon matrix containing free iron atoms, Fe+ ions, iron clusters, superparamagnetic iron, and ferromagnetic iron.333 The effect of pressure of up to 50kbar on the absorption spectra of five iron(m), two iron(n) and one mixed valence compound has been studied. In six of the compounds, but not in basic ferric acetate or soluble Prussian Blue, the observed pressure-induced bands were assigned to d-d transitions of converted iron(n) for the ferric compounds and to spin-forbidden d-d bands for the ferrous compounds. The charge-transfer band from iron(n) to iron(m) in soluble Prussian Blue showed a blue shift at pressures up to 7.2 kbar.334... 

The Mossbauer spectra of powdered samples of the clathrate are shown in Fig. 1. The statistics of the spectra is very poor at high temperature due to a low Debye-Waller factor (the absorption is 0.4 % at 320 K) and a relaxation phenomenon(absorption becomes broad in the region of the releixation time of 120 ns. The accumulated counts are more than a million counts above 250 K. The low temperature spectra of this clathrate are quite normal The efg for ferrocene derivatives is known to be essentially of molecular origin and the QS values do not... 

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