ESR Study of VOF53− Ion

Spin‐Hamiltonian parameters for the VOF₅³⁻ ion were determined from solution, frozen glass, powder, and single‐crystal ESR spectra. The most important finding is the presence of superhyperfine splittings due to the equatorial and axial fluorine ligands; the strongest interaction is found to result from the in‐plane $\pi$ bonding between the ${\text{3d}}_{\mathrm{xy}}$ orbital of vanadium and the ${\text{2p}}_y$ orbitals of fluorine. Bonding in the complex ion has been discussed in terms of LCAO MO theory.