Intervalence charge transfer across noncovalent interactions on vinyl silyl bridged biferrocenyl compounds

A series of vinyl-silyl-functionalized biferrocenyl compounds were very recently synthesized and studied by our group through cyclic (CV) and square-wave (SWV) voltammetric techniques, showing two well-resolved one-electron transfer oxidation processes. This fact might reflect a certain degree of electronic communication between ferrocenyl centers, but solvent or electrolyte effects could have an influence in the splitting. Gas-phase theoretical studies were carried out in order to determine the degree of iron–iron communication in absence of undesired environmental effects, revealing through the analysis of the topology of the electron density with different methods that organosilicon bridges between ferrocenyl units have mainly a steric but not an electronic-linking role, which is however of crucial importance, as they allow non-covalent paths for electronic communication between iron centers.