2p x-ray absorption of iron-phthalocyanine

3d transition metal ions, like Fe(II) in a planar organic environment are subject to the details of the ligand coordination. In this study the 3d orbital splitting in planar D4h symmetry is investigated for Fe(II) using the charge transfer multiplet program. By variation of the 10Dq, Ds and Dt crystal field parameters, the 3d orbitals split differently giving rise to different spin multiplicity. The relative occupations of the 3d orbitals yield a range of ground states. Experimental x-ray absorption spectra of FePc powder are compared with theoretical simulations, resulting in the spin ground state of the Fe(II) ion being 3E.