Optimized coordinates otained from DFT calculations, Cyclic Voltammetry measurements and results of stopped-flow UV/Vis spectroscic measurements were deposited.

The stopped-flow measurements were performed with a HI-TECH Scientific SF-61SX2 device with a diode array detector. The optical light path for transmission of the quartz glass cuvette was 10 mm.

The measurements were performed with a METROHM AUTOLAB PGSTAT 101 potentiostat using a three-electrode arrangement with a Pt disc working electrode (1 mm diameter), a Pt wire as counter electrode and an Ag/AgCl (in saturated ethanolic LiCl) reference electrode. The measurements were performed in MeCN and 100 mmol/L NBu4PF6 with a sample concentration of 1 mmol/L at room temperature. Ferrocene was added as an internal standard after the measurements of the sample and all potentials are referenced relative to the Fc/Fc+ potential. Cyclic voltammograms were measured with 200 mV·s–1, 100 mV·s–1, 50 mV·s–1 and 20 mV·s–1.