Functionalized pentamethylferrocenes: Synthesis, structure, and electrochemistry

Article abstract of DOI:10.1016/S0022-328X(97)00133-2

The advantageous properties of the Cp ^* ligand - intensified electron donation, steric bulk, and enhanced solubility in comparison to the ubiquitous Cp ligand - are finding increasing use in organometallic chemistry. A systematic evaluation of synthetic routes to pentamethylferrocene compounds with a wide range of functionalities, including carboxyl, carbonyl, aminomethyl, vinyl, ethynyl, fulvenyl, cyclopentadienylmethyl, and others is reported. Spectroscopic, structural, and electrochemical properties of such functionalized pentamethylferrocenes Fc ^{* /2}-R are compared to those of non-methylated ferrocenes Fc-R. The electronic influence of the Cp ^* ligand in these unsymmetrical ferrocenes Fc ^{* /2}-R has been studied by cyclic voltammetry measurements, demonstrating a decrease in oxidation potential of -0.276V in direct comparison to non-methylated ferrocenes Fc-R.