ja8b08520_si_002.cif (5.51 MB)
Hemilabile Proton Relays and Redox Activity Lead to {FeNO}x and Significant Rate Enhancements in NO2– Reduction
dataset
posted on 2018-11-14, 00:00 authored by Pui Man Cheung, Kyle T. Burns, Yubin M. Kwon, Megan Y. Deshaye, Kristopher J. Aguayo, Victoria F. Oswald, Takele Seda, Lev N. Zakharov, Tim Kowalczyk, John D. GilbertsonIncorporation
of the triad of redox activity, hemilability, and
proton responsivity into a single ligand scaffold is reported. Due
to this triad, the complexes Fe(PyrrPDI)(CO)2 (3) and Fe(MorPDI)(CO)2 (4) display 40-fold enhancements in the initial rate of NO2– reduction, with respect to Fe(MeOPDI)(CO)2 (7). Utilizing the proper sterics
and pKa of the pendant base(s) to introduce
hemilability into our ligand scaffolds, we report unusual {FeNO}x mononitrosyl iron complexes (MNICs) as intermediates
in the NO2– reduction reaction. The {FeNO}x species behave spectroscopically and computationally
similar to {FeNO}7, an unusual intermediate-spin Fe(III)
coupled to triplet NO– and a singly reduced PDI
ligand. These {FeNO}x MNICs facilitate
enhancements in the initial rate.