✦ LIBER ✦

Electric field-induced decrease of quantum yield of charge separation in photosynthetic reaction centers

✍ Scribed by A. Ogrodnik; T. Langenbacher; G. Bieser; J. Siegl; U. Eberl; M. Volk; M.E. Michel-Beyerle

Publisher: Elsevier Science
Year: 1992
Tongue: English
Weight: 586 KB
Volume: 198
Category: Article
ISSN: 0009-2614
DOI: 10.1016/0009-2614(92)85044-b

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✦ Synopsis

Electric field effects on reaction centers from Rb. sphaeroides have been detected in ps-transient absorption at 90 K. Upon application of a field of 7 X 10s V/cm the bleaching of the bacteriopheophytin at the A branch (H,, 545 nm) monitored after 30 ps mirrors a reduction of the quantum yield of P+H, by z 1 II (P being the special pair). A similar field-induced reduction of the quantum yield is observed when probing the bleaching of P at 870 nm. However, this effect evolves with a time constant of % 900 ps. We conclude that the loss channel employs an intermediate state with this lifetime before repopulating the ground state. Field-induced formation of P*Hi at the B branch was excluded from measurements in the Q, transiton of Hr, at 533 nm.

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