Synthesis and intramolecular electronic interactions of hexaarylbenzene bearing redox-active Cp*(dppe)Fe-C≡C- termini.

Abstract Hexaphenyl- (1) and hexathienyl-benzene (2) complexes with the six redox-active Cp*(dppe)Fe-C≡C- units are synthesized and their properties in terms of molecular junction are investigated. Both complexes show stepwise multi-redox processes and IVCT bands in the NIR region upon progressive oxidation from the neutral to hexacationic state, as a result of intramolecular electron transfer processes via troidal conjugation through the peripheral aromatic rings. Judging from the V ab values obtained by deconvolution analysis, electronic interaction for thienylene derivative 2 turns out to be stronger than that for the phenylene complex 1. DFT analysis of model complexes support superio'r electron transfer properties for the thienyl derivatives. Graphical abstract Image 1 Highlights • Synthesis of hexaphenyl- and hexathienyl-benzene complexes bearing the six peripheral redox-active Cp*(dppe)Fe-C≡C- termini. • Communication between the peripheral iron centers through toroidal conjugation as analyzed by electrochemistry and IVCT bands. • A DFT study of the model complexes supports the stronger toroidal conjugation for the hexathienyl complex. [ABSTRACT FROM AUTHOR]