All manipulations were carried out under argon with the exclusion of water and oxygen using standard Schlenk line and glove box techniques. Toluene, hexane and benzene were dried by refluxing over potassium, degassed, and stored over potassium mirrors. Dichloromethane (DCM) and fluorobenzene (FB) were dried over CaH2, degassed, and stored over 4 Å molecular sieves. C6D6 and CD2Cl2 were dried by refluxing over potassium or stirring over CaH2 respectively, before being vacuum distilled and freeze-pump-thaw degassed three times prior to use. 1-Ln, 9-10 2-Sm 10 and 3-Ln were prepared by literature methods; TEMPO • was purchased from Sigma-Aldrich and purified by sublimation prior to use. 1 H (400 and 500 MHz), C{ 1 H} (100 MHz and 126 MHz), B (128 and 160 MHz), F (376 and 470 MHz) and 29 Si (79.5 and 99 MHz) DEPT NMR spectra were obtained on Avance III 400 MHz or 500 MHz spectrometers at 298 K. These were referenced to the residual solvent resonance where present, or otherwise to external SiMe4 ( 1 H, C, Si), H3BO3/D2O ( 11 B) or trifluorotoluene/CDCl3 ( 19 F). UV-vis-NIR spectroscopy was performed on samples in Young's tap-appended 10 mm path-length quartz cuvettes on an Agilent Technologies Cary