Electronic conjugation pathways in ferrocenyl Schiff bases

Abstract

Mössbauer spectroscopic data for a large number of ferrocene Schiff-base compounds have been obtained. The ferrocene entities are used as sensitive probes to understand the electron distribution throughout the molecules. The data are discussed in terms of conjugation interactions and the presence or absence of coplanarity in the substituents on the ferrocene molecules. The crystal structures of ferrocenylimines of formula [Fe(η⁵-C₅H₅)(η⁵-C₅H₄CRNR′)] with R = H, R′= CH₂Ph and R = R′= Ph have been determined and the bonding details, and those in other known structures, are used together with the Mössbauer spectroscopic data to obtain a qualitative understanding of the bonding in these compounds.