Electron-Transfer Thermodynamics, Valence-Electron Hybridization, and Bonding for Iron Compounds

Abstract

The electron-transfer thermodynamics (a) for iron compounds (FeX_m) and complexes (FeL_n) and (b) for their heteroatoms (X/X⁻) and ligands (L/L⁻) in combination with other physical data provide insight into the valence-electron hybridization and bonding of the iron center. The basic conclusions are: (a) the chemical bonding of iron in its compounds and complexes is covalent and similar to that of carbon. (b) the electron-transfer processes of iron complexes are ligand-centered, and (c) the iron-ligand covalent bond energies can be evaluated from the electrochemically determined redox thermodynamics.

Key Words:

• iron complexes
• iron porphyrins
• electronegativities
• covalent bond energies
• covalent bonding
• iron-oxygen bonds
• iron proteins