Electronic structure study by means of x-ray spectroscopy and theoretical calculations of the ``ferric star'' single molecule magnet

Abstract

The electronic structure of the single molecule magnet system {M[Fe(L-1)(2)](3)}center dot 4CHCl(3) [M=Fe,Cr;L-1=CH3N(CH2CH2O)(2)(2-)] has been studied using x-ray photoelectron spectroscopy, x-ray-absorption spectroscopy, soft-x-ray emission spectroscopy, as well as theoretical density-functional-based methods. There is a good agreement between theoretical calculations and experimental data. The valence band mainly consists of three bands between 2 and 30 eV. Both theory and experiments show that the top of the valence band is dominated by the hybridization between Fe 3d and O 2p bands. From the shape of the Fe 2p spectra it is argued that Fe in the molecule is most likely in the 2+ charge state. Its neighboring atoms (O,N) exhibit a magnetic polarization yielding effective spin S=5/2 per iron atom, giving a high-spin state molecule with a total S=5 effective spin for the case of M=Fe. (c) 2006 American Institute of Physics.