Bonhommeau Sébastien, Ottosson Niklas, Pokapanich Wandared, Svensson Svante, Eberhardt Wolfgang, Björneholm Olle, Aziz Emad F
BESSY GmbH., Albert-Einstein-Strasse 15, Berlin, Germany.
J Phys Chem B. 2008 Oct 9;112(40):12571-4. doi: 10.1021/jp8071266. Epub 2008 Oct 1.
The local electronic structure of Fe(III) and Fe(II) ions in different alcohol solutions (methanol, ethanol, propan-1-ol) is investigated by means of soft X-ray absorption spectroscopy at the iron L 2,3-edge. The experimental spectra are compared with ligand field multiplet simulations. The solvated Fe(III) complex is found to exhibit octahedral symmetry, while a tetragonal symmetry is observed for Fe(II). A decrease in the solvent polarity increases the charge transfer from the oxygen of the alcohol to the iron ions. This conclusion is supported by Hartree-Fock calculations of the Mulliken charge distribution on the alcohols. A larger charge transfer is further observed from the solvent to Fe(III) compared to Fe(II), which is connected to the higher positive charge state of the former. Finally, iron ions in solution are found to prefer the high-spin configuration irrespective of their oxidation state.
通过在铁L 2,3边缘的软X射线吸收光谱法，研究了不同醇溶液（甲醇、乙醇、丙醇-1）中Fe(III)和Fe(II)离子的局域电子结构。将实验光谱与配体场多重态模拟进行了比较。发现溶剂化的Fe(III)络合物呈现八面体对称性，而Fe(II)则观察到四方对称性。溶剂极性的降低增加了从醇的氧到铁离子的电荷转移。这一结论得到了醇上穆利肯电荷分布的哈特里-福克计算的支持。与Fe(II)相比，还观察到从溶剂到Fe(III)有更大的电荷转移，这与前者更高的正电荷状态有关。最后，发现溶液中的铁离子无论其氧化态如何都更喜欢高自旋构型。
