FIGURE 4.

The normalized intensities ratios () for the low frequency ¹H-ENDOR lines (see Fig. 3), as a function of the incubation time in D₂O for deuterated RCs (a) and for protonated RCs (b). The ¹H → ²H exchange times were obtained by fitting the experimental data (dots) with Eq. 3 (solid lines). The values of the exchange times τ₁ and τ₂ are shown in the inserts. Experimental conditions: Microwave frequency 35 GHz, T = 80 K, B_o at position corresponding to g_y (see Fig. 2). Optical absorbance of sample (a) and 50 (b).