Next, in situ electrolytic UV-vis spectra for the CV solution containing RsvH3 (1.0 × 10 -3 mol dm -3 ) using the OTTLE cell (Supporting Information, Figure ) were measured in the absence of O2 under purging N2 gas and in the presence of O2 (Figure ). The spectrum of RsvH3 alone has a characteristic absorption band centered at 220 nm (black bold). Under the applied potential at 1.0 to -2.0 V vs. Fc + /Fc without O2, the spectrum did not change where any potential was applied (data not shown), demonstrating that RsvH3 is not electrolyzed in the potential range.