Synthesis, Spectroscopy, and Electrochemistry of (α-Diimine)M(CO)3Br, M = Mn, Re, Complexes: Ligands Isoelectronic to Bipyridyl Show Differences in
CO2 Reduction

Vollmer, Matthew
V.; Machan, Charles W.; Clark, Melissa L.; Antholine, William E.; Agarwal, Jay; Schaefer, Henry F.; Kubiak, Clifford P.; Walensky, Justin R.

doi:10.1021/om500838z.s001

Synthesis, Spectroscopy, and Electrochemistry of (α-Diimine)M(CO)3Br, M = Mn, Re, Complexes: Ligands Isoelectronic to Bipyridyl Show Differences in CO2 Reduction

https://doi.org/10.1021/om500838z.s001
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journal contribution

posted on 2015-01-12, 00:00 authored by Matthew V. Vollmer, Charles W. Machan, Melissa L. Clark, William E. Antholine, Jay Agarwal, Henry F. Schaefer, Clifford P. Kubiak, Justin R. Walensky

The synthesis and characterization of new Mn(I)- and Re(I)-centered organometallic complexes fashioned with 1,4-diazabutadiene (DAB) ligands is reported. Ten compounds of the type fac-(α-diimine)M(CO)3Br (M = Mn, Re) were obtained in moderate to excellent yield (35–80%) and high purity from the coordination of the five ligands with M(CO)5Br in refluxing ethanol. Despite the electronic similarity of DAB to 2,2′-bipyridyl, the complexes described herein were poor mediators of electrochemical CO2 conversion to CO, but provide insight into the role of redox-active ligands in catalysis. Additional characterization of the one-electron reduced rhenium compounds, relevant intermediates in CO2 reduction, by EPR and single-crystal X-ray analysis is described.