Fig. 3. (a) Echo detected (black trace) and CW (red trace) experimental EPR spectra of 1sol_{1 mM}, measured at 5 K, and best simulations (dotted traces). The arrow marks the field position of T₁ and T_m determination. (b) Temperature dependence of T₁ and T_m for 1sol_{1 mM} sample. Full symbols refer to experiments of echo saturation by fast repetition, empty ones to inversion recovery experiments (see ESI† for details). The solid line corresponds to the best-fit of the high temperature data with T₁ ∝ T^–n.