EPR and DFT Studies of the One-Electron Reduction Product of Phospholium Cations

Phys Chem Chem Phys. 2006 Feb 21;8(7):862-8. doi: 10.1039/b513736p. Epub 2005 Dec 19.


Cyclic voltammetry and EPR spectroscopy show that cationic phospholium groups are good electron acceptors whose reduction leads to a neutral radical where the unpaired electron is mainly delocalized on the carbon atoms of the five-membered ring. DFT calculations together with the crystal structure of phospholiums indicate that the electron addition causes a drastic diminution of the exocyclic CPC angle. The SOMO of reduced phospholium is compared to the SOMO of the phosphole radical anion.