Upon the addition of chloroamide 1a, a new broad absorption band (λmax = 480 nm) was observed, suggesting the formation of a CT complex between the FMNhq and 1a. Interestingly, we found nitroalkane 2a can oxidize the ground state FMNhq to generate a flavin feature with an absorption band around 450 -500 nm. We attribute this feature to a mixture of flavin quinone and flavin semiquinone (Supplementary Fig. ). Interestingly, when nitroalkane 2a is mixed with CsER and cofactor turnover mix under visible light irradiation, we do not observe reduction to the oxime, hydroxylamine, or hydrodenitrated products. This suggests that initial reduction of the nitroalkane can occur, in contrast to examples with photoredox catalysts, but subsequent electron transfers to form oximes and hydroxylamines do not transpire, making this single electron reduction event reversible under the reaction conditions. As the first irreversible step is the reduction of the alkyl halide, reversible nitroalkane reduction does not have a detrimental effect on the reaction.