Figure 2. Transient absorption measurements.

(a) Transient absorption difference spectra [ΔA(λ)] of DmCry at different delay times after the photo-excitation laser pulse, showing ground-state bleaching (420 < λ < 480 nm) and radical production (λ > 500 nm). (b) Decay of the ΔA(λ) signal averaged over the spectral region 560–620 nm in the absence (black) and presence (red) of a 22 mT magnetic field. (c) Shows the corresponding magnetic field action response (red minus black, ΔΔA) displaying a rapid rise followed by a slow (τ = 36 ± 2 μs) decay. (d) Time response of the ΔA signal at 510 nm (recorded separately, with additional averaging) in the absence (black) and presence (red) of a 22 mT magnetic field. (e) The corresponding action signal shows a rapid rise in the magnetic field effect (complete within 10 μs) which is then long-lived. All transient absorption experiments were performed at 267 K in 50% v/v glycerol solution.