Correlation between N 1s XPS Binding Energy and Bond Distance in Metal Amido, Imido, and Nitrido Complexes

Synchrotron-based X-ray photoelectron spectroscopy is used to measure N 1s binding energies of several metal amido, imido, and nitrido complexes of group 5 and 6 metals. The N 1s binding energy decreases as the formal M−N bond order increases. A simple correlation between the contraction of the M−N bond and the lowering of binding energy is also observed. This correlation supports a notion that the bonding character of a linear metal−imido linkage resembles that of a metal−nitrido linkage closely.