Te011 er 4122shqe cavity

EPR samples of Fe(iii)-MC6*a were prepared in 50 mM phosphate buffer (pH 6.5) with 50% TFE (v/v) at a concentration of 0.25 mM. The samples were transferred to EPR-tubes and flash-frozen in liquid N₂. Samples of intermediates were prepared by rapid mixing Fe(iii)-MC6*a with one equivalent of H₂O₂ and either 1 or 0.5 equivalents of TCP (final concentration of 0.25 mM Fe(iii)-MC6*a) in an EPR tube, and flash freezing in liquid N₂ immediately or after 2 min, as stated in the figure captions. The prepared samples were stored at 77 K between measurements.
X-band EPR measurements were performed on a Bruker ELEXYS E500 spectrometer equipped with a SuperX EPR049 microwave bridge and a cylindrical TE011 ER 4122SHQE cavity in connection with an Oxford Instruments continuous flow cryostat. Measuring temperatures were achieved using liquid helium flow through an ITC 503 temperature controller (Oxford Instruments). Modulation frequency at 100 kHz was set in all measurements. Bruker Xepr software package was used for all data processing. The EPR simulation was performed using EasySpin using the EasySpin MATLAB toolbox.^{58 (link)}