%0 Journal Article %A Pollock, Christopher J. %A Grubel, Katarzyna %A Holland, Patrick L. %A DeBeer, Serena %D 2013 %T Experimentally Quantifying Small-Molecule Bond Activation Using Valence-to-Core X‑ray Emission Spectroscopy %U https://acs.figshare.com/articles/journal_contribution/Experimentally_Quantifying_Small_Molecule_Bond_Activation_Using_Valence_to_Core_X_ray_Emission_Spectroscopy/2387011 %R 10.1021/ja3116247.s001 %2 https://ndownloader.figshare.com/files/4026700 %K probe %K molecule activation %K N 2 2 %K 0.02 Å %K N 2 bond activation %K length %K XES %X This work establishes the ability of valence-to-core X-ray emission spectroscopy (XES) to serve as a direct probe of N2 bond activation. A systematic series of iron-N2 complexes has been experimentally investigated and the energy of a valence-to-core XES peak was correlated with N–N bond length and stretching frequency. Computations demonstrate that, in a simple one-electron picture, this peak arises from the N2 2s2s σ* orbital, which becomes less antibonding as the N–N bond is weakened and broken. Changes as small as 0.02 Å in the N–N bond length may be distinguished using this approach. The results thus establish valence-to-core XES as an effective probe of small molecule activation, which should have broad applicability in transition-metal mediated catalysis. %I ACS Publications