Synthesis and electrochemistry of ferrocenemethylamine and its conjugated acid. Crystal structure of ferrocenemethylammonium chloride

Abstract

Ferrocenemethylamine ( 2) is conveniently synthesized by reductive ammination of ferrocene carboxaldehyde ( 1) in methanolic solution. The crystal structure of ferrocenemethylamine hydrochloride ( 3) is reported. In the solid state, 3 possesses a layered N–H⋯Cl–H-bonded network, resulting in the formation of 4- and 8-membered rings of alternating nitrogen and chlorine atoms, with an interlayer separation of 9.17 Å. The one-electron oxidation potentials of 2 and 3 in nine solvents are reported (CHCl 3, MeCN, MeOH, acetone, DMF, THF, nitrobenzene, EtOH, iPrOH). The present results have been used to evaluate the effects of different solvent parameters, such as the solvent polarizability and the solvent dielectric constant, on the redox properties of 2 and 3. The redox properties of 3 depend on the dielectric constant ε of the solvent.