Spin propensity in resonant photoemission of transition metal complexes

Abstract

Resonant photoelectron spectroscopy (RPES) has been used to probe electronic structure properties of the closed-shell [Fe^{II}(CN)_{6}]^{4−} and open-shell [Fe^{III}(CN)_{6}]^{3−} prototype transition metal complexes in aqueous solution. Site-selective Fe 2p (L-edge) RPES maps provide new insight into spin-coupling processes at the core-excited metal centers, with autoionization of [Fe^{III}(CN)_{6}]^{3−} showing a dramatic (∼4×) singlet versus triplet final-state enhancement. This shows that RPES provides unique opportunities to study spin-dependent electronic properties in transition metal based functional materials.