%0 Journal Article
%A van Brederode, Marion E.
%A H. M. van Stokkum, Ivo
%A Katilius, Evaldas
%A Mourik, Frank van
%A Jones, Michael R.
%A Grondelle, Rienk van
%D 1999
%T Primary Charge Separation Routes in the BChl:BPhe Heterodimer Reaction Centers
of Rhodobacter sphaeroides†
%U https://acs.figshare.com/articles/journal_contribution/Primary_Charge_Separation_Routes_in_the_BChl_BPhe_Heterodimer_Reaction_Centers_of_i_Rhodobacter_sphaeroides_i_sup_sup_/3588804
%R 10.1021/bi9829128.s001
%2 https://acs.figshare.com/ndownloader/files/5674740
%K excitation wavelength
%K B excitation
%K bacteriochlorophyll homodimer
%K pathway B
%K 880 nm excitation light results
%K charge separation process
%K HL 173L reaction center
%K 812 nm
%K state D
%K 43 ps decay
%K B B
%K 798 nm excitation light
%K excitation energy
%K charge separation
%K excitations results
%K Rhodobacter sphaeroides
%K ground state
%K monomeric bacteriochlorophylls
%K U.S.A
%K absorption spectra
%K Primary Charge Separation Routes
%K HM 202L heterodimer reaction center
%X Energy transfer and the primary charge separation process are studied as a function of excitation
wavelength in membrane-bound reaction centers of Rhodobacter sphaeroides in which the excitonically
coupled bacteriochlorophyll homodimer is converted to a bacteriochlorophyll-bacteriopheophytin heterodimer, denoted D [Bylina, E. J., and Youvan, D. C. (1988) Proc. Natl. Acad. Sci. U.S.A. 85, 7226]. In
the HM202L heterodimer reaction center, excitation of D using 880 nm excitation light results in a 43 ps
decay of the excited heterodimer, D*. The decay of D* results for about 30% in the formation of the
charge separated state D+QA- and for about 70% in a decay directly to the ground state. Upon excitation
of the monomeric bacteriochlorophylls using 798 nm excitation light, approximately 60% of the excitation
energy is transferred downhill to D, forming D*. Clear evidence is obtained that the other 40% of the
excitations results in the formation of D+QA- via the pathway BA* → BA+HA- → D+HA- → D+QA-. In
the membrane-bound “reversed” heterodimer reaction center HL173L, the simplest interpretation of the
transient absorption spectra following B excitation is that charge separation occurs solely via the slow
D*-driven route. However, since a bleach at 812 nm is associated with the spectrum of D* in the HL173L
reaction center, it cannot be excluded that a state including BB is involved in the charge separation process
in this complex.
%I ACS Publications