Electron paramagnetic resonance (EPR) spectra were recorded on a Bruker ELEXSYS 500 Xband spectrometer equipped with a Bruker ER4102ST resonator in a Wilmad flat cell for aqueous solutions (WG-808-Q) at RT. Experimental conditions were 512 points, with a microwave power of 20 mW, 0.1 mT modulation amplitude, and 100 kHz modulation frequency. The sweep range was 200 mT.