Journal of the American Chemical Society
Communication
a 10-fold enhancement in catalysis versus 2 (kRLS ≈ 200 M−1
s−1, TOF = 20 s−1). In this respect, catalysts 2 (Fe“0” active
species) and 3 (FeI active species) represent a unique
opportunity to explore differing mechanisms within the same
ligand/metal system at similar driving forces.
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The lower activity of dArFg-derived Fe catalysts versus
existing Co/Ni complexes may be substantially offset by the
greater abundance and lower cost of iron. We are now
exploring other electronic and structural modifications to the
{dArFgX} (X = H, BF2, BR2) ligand system in attempts to
achieve lower overpotentials and higher catalytic efficiencies.
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́
ASSOCIATED CONTENT
■
́
S
* Supporting Information
́
CIF for 1−3; additional spectra, experimental and simulated
CVs, and resulting analyses; and supporting reaction schemes.
This material is available free of charge via the Internet at
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AUTHOR INFORMATION
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Corresponding Author
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Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
This work was supported by the NSF CCI Solar Fuels Program
(CHE-0802907). M.J.R. was supported by an NSF ACC-F
Fellowship (CHE-1042009). The Bruker APEXII diffractom-
eter was obtained via an NSF CRIF:MU Award (CHE-
0639094). We thank Larry Henling and Michael Day for
solving the crystal structures.
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dx.doi.org/10.1021/ja300534r | J. Am. Chem. Soc. XXXX, XXX, XXX−XXX