Homotrimetallic oxazolo-ferrocene complexes displaying tunable cooperativeinteractions between metal centers and redox-switchable character

A synthetic procedure based on the aza-Wittig reaction of alpha -azidoacety l ferrocene or 1,1 ' -bis(alpha -azidoacetyl)ferrocene with-mono-, di-, and triacyl chlorides and triphenylphosphine has been developed to prepare the new homotrimetallic ferrocene Complexes 6, 9, and 10 containing at least t wo oxazole rings in the conjugation chain. Complexes 9 and 10 exhibited thr ee and two reversible redox processes, respectively, indicating significant electrostatic interaction between the iron centers in these complexes. Pro tonation properties of complexes 9-13 have been assesed by use of H-1 NMR a nd cyclic voltammetry measurements.