Effect of Phosphorus Substitution in the Cyclopentadienyl Ring of Ferrocene: Combined Mössbauer Spectroscopy and DFT Studies

Abstract

A series of phosphaferrocenes with different numbers of phosphorus atoms and phenyl groups in the cyclopentadienyl ring were successfully synthesized and studied by Mössbauer spectroscopy. Revealed Mössbauer hyperfine parameters are in line with density functional theory (DFT) calculations. It was found that substitution of CH-units by phosphorus atoms in the cyclopentadienyl ring affects the population of the molecular orbitals related to iron. These changes influence on Mössbauer hyperfine parameters, especially on the quadrupole splitting values. Intermolecular vibrations were analyzed in terms of the Debye model of solids based on the temperature dependence of Mössbauer absorption. The characteristic lattice Debye temperatures and the intermolecular force constants were calculated for each studied sample.