vibrational coherence transfer in LH-1 & prospects for vibrational control of

vibrational coherence transfer in LH-1 & prospects for vibrational control of electronic excitation transfer jason biggs &jeff cinadepartment of chemistry & oregon center for opticsuniversity of oregon supported by us-nsf & acs-prf

photosynthetic electronic energy transfer can be accompanied by vibrational coherence transfer LH1-RC structure cogdell et al. science 2003 fluorescence up-conversion at room temperature bradforth, jimenez, van mourik, van grondell & fleming, j. phys. chem. 1995 ultrafast absorption-difference at 5 K monshouwer, baltuska, van mourik & van grondelle, j. phys. chem. a 1998

vibrational coherence transfer and trapping … energy transfer complexes cina & fleming j phys chem a 2004 state-1’ (ge) state-1 (eg)

wave-packet trajectory in donor-excited state affects short-time EET biggs & cina jcp submitted 2009 state-1’ (ge) franck-condon-excited wave packet state-1 (eg)

wave-packet trajectory in donor-excited state affects short-time EET biggs & cina jcp submitted 2009 state-1’ (ge) franck-condon-excited wave packet state-1 (eg) initially-displaced wave packet

wave-packet trajectory in donor-excited state affects short-time EET biggs & cina jcp submitted 2009 state-1’ (ge) 1’ franck-condon-excited wave packet state-1 (eg) 1 initially-displaced wave packet Peg(t) donor-state population oriented model system horizontally polarized pump withoutorwithprior displacement to qb= - d

“acceptor” excited —> <— both monomers excited vibrationally-perturbed nl-WPI (& pump-probe spectroscopy) on a collection of identical, randomly oriented dimers both monomers unexcited —> <— “donor” excited all pulses nonzero duration, independently polarized pulse sequence: signal is the population of one-exciton manifold 2nd-order in sub-resonant “control” pulse and quadrilinear in the wpi-pulses having a given optical phase-signature

in thepump-probe limitof nl-WPI difference measurement,pulse sequence simplifies …

for example, nl-WPI signal contribution with phase-signature is with pump-probe limit :

for example, nl-WPI signal contribution with phase-signature is with

the corresponding nuclear wave packet is a linear superposition of the form

electronic state-space pathways contributing to

initial trajectories in donor-excited state initially-displaced wave packet state-1’ (ge) franck-condon- excited wave packet state-1 (eg)

initial trajectories in donor-excited state initially-displaced wave packet state-1’ (ge) wave packet generated by ISRS & short- pulse electronic absorption franck-condon- excited wave packet state-1 (eg) ISRS generates nuclear motion with maximum displacement less than d

donor-excited state population ISRS-generated wave packet 1’ franck-condon-excited wave packet 1 donor-state population of oriented model system after interaction with vertically polarized ISRS & horizontally polarized pump pulses

pump-probe&pump-probe difference signals fromisotropic sample without&withstimulated-Raman excitation P-pulse ISRS polarization pump (A) & probe (C) polarization

(simulated-emission contribution to)pump-probe&pump-probe difference signalsfrom anoriented sample 1’ 1 P-pulse ISRS polarization pump (A) & probe (C) polarization

pump-probe & pump-probe difference signals from isotropic, inhomogeneously broadened sample site energies chosen from independent Gaussian distributions of FWHM  pulse parameters same as before, except

accelerated EET in the downhill case? initially-displaced wave packet franck-condon- excited wave packet

donor-excited state population in downhill EET 1’ franck-condon-excited wave packet 1 ISRS-generated wave packet donor-state population of oriented downhill system after interaction with vertically polarized ISRS & horizontally polarized pump pulses

pump-probe&pump-probe difference signals from isotropic sample ofdownhill EET complex VHH P-pulse ISRS polarization HH pump (A) & probe (C) polarization

contributions to signals from downhill EET complex: VHH stimulated-emission HH excited-state absorption pump-probe signal pump-probe difference signal ground-state bleach

pump-probe & pump-probe difference signals from isotropic sample ofdownhill EET complex V-polarized & red-shifted probe VHV ISRS (P) & probe (C) polarization HV pump (A) polarization

anthracene monomer fluorescence lambert et al. JCP 1984 dithia-anthracenophane (DTA)  = 385 cm-1 = 0.557  = 1400 cm-1 = 1.05 DTA fluorescence anisotropy yamazaki et al. j phys chem A 2002 J = 22.9 cm-1

pulse power spectra & schematic absorption spectra anthracene anthracene-12 P-pulse (ISRS) A-pulse (pump) C-pulse (probe)

DTA-12 donor-state population dynamics without ISRS donor-state population with ISRS (t - tA)/12

polarized pump-probe & pump-probe difference signalsfrom DTA-12 VHH anisotropy HH pump-probe pump-probe difference stimulated-emission only 100-cm-1 site-energy broadening other parameters the same, except

when , the survival probability reduces to idiosyncracies of (antisymmetric-mode) Franck-Condon overlaps may offer a prospect for exerting vibrational control over EET, even in the weak electronic-vibrational coupling case . in DTA-12, for example, qb/d donor-state population qa/d

next steps … vibrational control of EET in (biological?) multi-chromophore complexes optimize duration, center frequency, and chirp-rate of P-pulse for large-amplitude acceptor-mode displacement calculate & interpret full nl-WPI difference signals, with all polarization combinations include vibrational relaxation and dephasing via Redfield theory calculate & interpret nl-WPI difference signals from Jahn-Teller active (or other) systems with conical intersections following ISRS-excitation of coherent pseudo-rotation; prepare & observe dynamical Slonczewski resonances?

vibrational coherence transfer in LH-1 & prospects for vibrational control of