Mössbauer measurements on iron phthalocyanines

Monomeric and polymeric iron phthalocyanines (FePc) with and without carbon support and subjected to various heat treatments have been studied by Mössbauer spectroscopy. Dispersing FePc on carbon changes the electronic state of the monomer to low spin (S = 0) while the electronic state of the polymer remains unchanged (S = 1). It is suggested that the bonding between polymeric FePc and carbon takes place through the side groups present on the peripheral parts of the polymer and/or through suitable chemical groups present on the carbon surface. The electron-attracting ability of the side-groups deduced from the Mössbauer spectra is discussed. The results will form a basis for a comparison with data from electrochemical measurements.