view article
Figure 8
Room-temperature results of the laser-induced changes in the XAFS of the PSII manganese complex. The experimental setup depicted in Fig. 7[link] was used. (a) Time course of the X-ray fluorescence intensity at 6551.5 eV of the manganese complex (edge region) driven repeatedly through its catalytic cycle by a sequence of ten laser flashes (at 291 K). The quaternary oscillations verify the cyclic progression of the manganese complex through the S-state cycle. The damping of the quarternary oscillation is well reproduced using an initial population of S1 of 100% and 15% of `misses' (closed circles represent the simulated values). From these numbers, we estimate the yields of S1, S2 and S3 after flashes 0, 1 and 2 to be 100, 85 and 72%, respectively. (b) Fourier transforms of k3-weighted EXAFS spectra collected at room temperature for predominant population of the S1, S2 and S3 states. Dark adaptation resulted in exclusive population of the S1 state; by applying one and two laser flashes the S2 and S3 states, respectively, were populated. Immediately after the flash illumination a rapid EXAFS scan lasting for not more than 10 s was started (simultaneous scans of monochromator and undulator gap, beamline ID26, ESRF, Grenoble).

Journal logoJOURNAL OF
SYNCHROTRON
RADIATION
ISSN: 1600-5775
Volume 10| Part 1| December 2003| Pages 76-85
doi:10.1107/S090904950201720X
Follow J. Synchrotron Rad.
Sign up for e-alerts
E-alerts
Follow J. Synchrotron Rad. on Twitter
Twitter
Follow us on facebook
Facebook
Sign up for RSS feeds
RSS