Probing Edge/Support Electronic Cooperativity in Single Edge Fe/Co 6 Se 8 Clusters.

This study provides insights into the electronic structure of an atomically precise Fe/Co 6 Se 8 cluster and the extent of redox cooperativity between the Fe active site and the noninnocent Co 6 Se 8 support. Chemical oxidation studies enable the isolation of two types of oxidized Fe/Co 6 Se 8 clusters, in which the nature of the counterion (I - or OTf - ) significantly impacts the structural interactions between Fe and the Co 6 Se 8 unit. Experimental characterization by single crystal X-ray diffraction, 57 Fe Mössbauer spectroscopy, and 31 P{ 1 H} NMR spectroscopy is complemented by computational analysis. In aggregate, the study reveals that upon oxidation, the charge is shared between the Fe edge site and the Co 6 Se 8 core.