Resonant inelastic X-ray scattering (RIXS) and X-ray absorption (XA) experiments at the iron L- and nitrogen K-edge are combined with high-level first principles restricted active space self-consistent field (RASSCF) calculations for a systematic investigation of the nature of the chemical bond in potassium ferrocyanide in aqueous solution. The atom- and site-specific RIXS excitations allow for direct observation of ligand-to-metal (Fe L-edge) and metal-to-ligand (N K-edge) charge transfer bands and thereby evidence for strong {\sigma}-donation and {\pi}-back-donation. The effects are identified by comparing experimental and simulated spectra related to both the unoccupied and occupied molecular orbitals in solution.
@article{arxiv.1312.0236,
title = {Chemical Bonding in Aqueous Ferrocyanide: Experimental and Theoretical X-ray Spectroscopic Study},
author = {Nicholas Engel and Sergey I. Bokarev and Edlira Suljoti and Raul Garcia-Diez and Kathrin M. Lange and Kaan Atak and Ronny Golnak and Alexander Kothe and Marcus Dantz and Oliver Kühn and Emad F. Aziz},
journal= {arXiv preprint arXiv:1312.0236},
year = {2013}
}