F. Varret et al., A DOUBLE ORIGIN PROPOSED FOR THE VARIOUS MOSSBAUER-SPECTRA OF BIFERROCENIUM SALTS - CHARGE ORDERING AND MOLECULAR BISTABILITY, Chemical physics, 212(2-3), 1996, pp. 487-495
We propose a general explanation for the various Mossbauer spectra of
biferrocenium salts, based on the ambiguous character of the HOMO (hig
hest occupied molecular orbital) of the moieties of these mixed-valenc
e salts. This way we both reproduce fusion-type and coexistence-type s
pectra. Orbital crossovers involved by the model are recognized as an
effect of molecular bistability.