ja3116247_si_001.pdf (2.04 MB)
Experimentally Quantifying Small-Molecule Bond Activation Using Valence-to-Core X‑ray Emission Spectroscopy
journal contribution
posted on 2013-08-14, 00:00 authored by Christopher
J. Pollock, Katarzyna Grubel, Patrick L. Holland, Serena DeBeerThis
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.