L-edge sum rule analysis on 3d transition metal sites: from d10 to d0 and towards application to extremely dilute metallo-enzymes

摘要: According to L-edge sum rules, the number of 3d vacancies at a transition metal site is directly proportional integrated intensity X-ray absorption spectrum (XAS) for corresponding complex. In this study, numbers holes are characterized quantitatively or semi-quantitatively series manganese (Mn) and nickel (Ni) complexes, including electron configurations 3d10 → 3d0. addition, extremely dilute (<0.1% wt/wt) Ni enzymes were examined by two different approaches: (1) using high resolution superconducting tunnel junction detector obtain XAS spectra with very signal-to-noise ratio, especially in non-variant edge jump region; (2) adding an inert tracer sample that provides prominent spectral feature replace weak normalization. publication, we present first time: rule analysis Mn complexes include from open shell 3d0 closed 3d10; systematic on uncertainties, jump, which was missing all previous reports; (3) clearly-resolved between pre-L3 post-L2 regions sample; (4) evaluation alternative normalization standard analysis. copper (Cu) proteins measured conventional semiconductor also repeated as bridges enzymes. The differences measuring 1% Cu <0.1% compared discussed. This study extends virtually any complex biological samples contain metals.