Fig. 3. (a and b) Relaxation time constants extracted from pulse-EPR spectroscopy for complexes diluted in a diamagnetic analogue (1′–3′) and in OTP (1′′–3′′). T1 was obtained through saturation recovery, wherein a train of short microwave pulses saturates the transition and the return to equilibrium is monitored. Tm was obtained through a two-pulse Hahn echo experiment, wherein coherence loss in the superposition state is monitored. (c) Fits of the T1 relaxation data for 1′–3′ to eqn (1). The shaded regions correspond to the process which is dominant in that temperature regime.
