A spectroscopic, electrochemical and DFT study of para-substituted ferrocene-containing chalcone derivatives: Structure of FcCOCHCH(p- ~tBuC _6H _4)

摘要

A comparative investigation of seven ferrocene-containing chalcones (Fc-CO-CHCH-C _6H _4R, with R = OCH _3, CH _3, Ph, tBu, H, Br and CF _3) has been performed based on their electrochemical and spectroscopical behavior as well as with DFT calculations. These compounds were prepared by Claisen-Schmidt condensation of acetylferrocene and the appropriate benzaldehyde derivative. All compounds exhibited reversible chemical and electrochemical behavior, as confirmed by ΔE = 83 - 93 mV and i _(pc)/i _(pa) = 0.93 - 1.00. The formal reduction potential E°′ for the compounds ranged between 231.0 and 261.5 mV versus FcH/FcH ~+ as an internal standard. The UV-Vis spectra of all ferrocene-containing chalcones showed the characteristic peaks for aromatic systems at ±380 nm and a peak in the visible region at ±490 nm, which is attributed to the ferrocene moiety. FTIR of all the ferrocene-containing chalcones showed a characteristic CO stretching peak at ±1650 cm ~(-1). DFT calculated HOMO energies and ionization potentials correlate well with experimentally measured E°′ values.