Electronic Coupling in Triferrocenylpnictogens

From a fundamental
perspective, studies of novel mixed-valent complexes
containing ferrocenyl units are motivated by the prospect of improving
and extending electron transfer models and theories. Here, the series
of triferrocenylpnictogens Fc3E was extended to the heavier
analogues (E = As, Sb, and Bi), and the influence of the bridging
atom was investigated with Fc3P as a reference. Electrochemical
studies elucidate the effect of electrostatic contribution on the
large redox splitting (ΔE1) exhibited
by the compounds and solvent stabilization in the case of Fc3As. Structural characterization of the triferrocenylpnictogens combined
with spectroelectrochemical studies indicates weak electronic couplings
in the related cations [Fc3E]+, suggesting a
through-space mechanism.