Halina Abramczyk. 1 Laser Molecular Spectroscopy Technical

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1 prof. Halina Abramczyk Laboratory of Laser Molecular Spectroscopy Technical University of Lodz Poland solvation dynamics of an excess electron vibrational relaxation in H-bonded systems correlation between vibrational dynamics and phase transitions vibrational relaxation in liquids, glasses, crystals and supercooled liquids photochemistry vibrational and prof. electronic Halina Abramczyk dynamics Laboratory of in bacteriorhodopsine

2 Professor Halina Abramczyk Dr. Gabriela Waliszewska M. Sc. Iwona Szymczyk M. Sc. Agnieszka Lebioda Dr. Beata Brozek-Pluska Marta Jackowicz Dr. Katarzyna Paradowska-Moszkowska M. Sc. Gabriela Wiosna

3 Prof. G.H. Atkinson University of Arizona Department of Chemistry 85 7 Tuscon, AZ, USA Dr. A. Terentis Dr. B. Mallish 3

4 - SO 3 SO - 3 C N N N N N C Fe C N Cu N N N N N C N - SO 3 - SO 3 4

5 CH CH 3 CH CH 3 CH N Lys H 5

6 Primary events in bacteriorhodopsin and its modified analogs: vibrational and electronic dynamics 36.. H. Abramczyk Femtosecond primary events in bacteriorhodopsin and its retinal modified analogs. revision of commonly accepted interpretation of electronic spectra of transient intermediates in BR photocycle, J.Chem.Phys., 0 (004) A. Terentis, L. Ujj, H. Abramczyk, G.H. Atkinson, Primary events in bacteriorhodopsin photocycle: torsional vibrational dephasing in the excited electronic state, Chem. Phys 33 (005)5-6 6

7 3 5 4 all-trans 3-cis 7

8 8

9 cytoplasm + H electrochemical gradient Hoover Dam water level gradient extracellular medium + H turbine ATP Synthase chemical energy ATP (Adenosine Triphosphate) electric energy 9

10 Experimental methods Resonance Raman Spectroscopy Femtosecond Absorption Spectroscopy Pump-Probe Picosecond time resolved CARS 0

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12 probe WC Dichroic Polarizator 04x56 Back Iluminated UV enhanced CCD detector pump

13 Coherent anti-stokes Raman Scattering (CARS) Fundamentals k k k s k as ω ω s ω as Phase matching factor: S ω ω s ω ω s ω as G = sin(δk.l/) (δk.l/) ω p S 0, ν > 0 δk = k k s - k as S 0 Resonance Raman PR/CARS (4-wave mixing) PTR/CARS PR/CARS = Picosecond Resonance CARS PTR/CARS = Picosecond Time-Resolved CARS 3

14 CARS: theory Intensity of the CARS signal: I as (ω as ) χ (3) (ω as,ω,ω s ). I.I s (ω s ). G Normalized CARS spectrum fitting function (-species mixture): I as I as Sample = Reference N A µ A e i + ( - η ) j - i j= j Θ j + N B A k e i η - i k= k Θ k Ω = Band Origin A = Amplitude Γ = Bandwidth Θ = Vibrational phase η = relative conc.(0 η ) µ = Scaling factor N = Number of vibrations χ (3) = third-order susceptibility j = (Ω j -(ω ω s )) / Γ j Background-free (Lorentzian lineshapes) spectral intensity: I raman = N j = A j (Ω j -(ω ω s )) + Γ j 4

15 Time resolved CARS frequency domain Prof. G.H. Atkinson University of Arizona Department of Chemistry 85 7 Tuscon, AZ, USA 5

16 * Lock-In Amp. Computer PD F M PTA Signal A Sample L * O AC G M Ref. L FM CARS Signals * Optical Delay Lines M * BE M CD M BE BS SHG THG BS CD CD M M BS PM M BS M Chopper BE M 6

17 L hν 8ms 00-00fs I 460 <500fs O 640 J 65 proton uptake from the cytoplasmic 3ps K 60 N 540 Asp-96 ms L 550 M 4 7 proton releas e to extracellurar surface 7

18 ) R.A. Mathies, S.W. Lin, J.B. Ames, W.T. Pollard, 99, Annu.Rev.Biophys.Chem.0, 49 ) T.G.Ebrey, 993, In:Thermodynamics of membranes, receptors and channels, CRC Press, New York, 353 3) J.K. Lanyi, 993, Biochim.Biophys.Acta, 83,4 4) J.K. Lanyi, 000, J. Phys. Chem. B 04,

19 -state model S(B) u H 00-00fs I Energy S(A) 0 g hν 700nm 860nm 500fs 65nm J BR trans K 3-cis 9 C =C torsional coordinate 3 4 9

20 Primary events in BR photocycle What happens between 0 and 500 fs? What does 0-00 fs dynamics reflect? When does isomerisation all-trans - 3- cis occurs? H, I, J species-?????? J- excited or ground state? 0 0

21 CARS results

22 Native BR-568 and unlocked analogs BR 6. and 6.9 BR-568 CH CH 3 CH 3 9 CH 3 CH N Lys H BR 6. CH CH 3 CH 3 9 CH N Lys H 0 CH 3 CH 3 BR Laser Molecular Spectroscopy CH 3 Technical 8 CH N H Lys

23 Locked analogs BR 5. and BR 5.3 CH CH 3 CH 3 BR CH 3 CH N Lys H CH CH 3 3 BR CH 3 CH N Lys H 3

24 BR-570 J-65 K-590 Raman Shift ( cm - ) Rel. CARS Intensity 4

25 Raman Shift [ cm - ] Rel. CARS Intensity C=C Stretch C=N Stretch 5 BR6. J6. K6.

26 Raman Shift [ cm - ] BR6. HOOP CH 3 -rock C-C Stretch J6. Rel. CARS Intensity 6 K6.

27 7 Table Vibrational dephasing rates characterized by the band widths of the C=C stretching mode for the for BR and its retinal modified analogs 6. and 6.9 compared to the vibrational dephasing rates for their J and K intermediates Ground state BR- 568 J- 65 K- 590 Ground state BR 6. J 6. K 6. Ground state BR 6.9 K 6.9 Maximum [cm - ] C=C Band width (FWHF) [cm - ]

28 Locked analogs BR 5. and BR 5.3 CH CH 3 CH 3 BR CH 3 CH N Lys H CH CH 3 8 BR CH 3 CH N Lys H 8

29 BR 5.3 Date:07/6/0 fitted for two species up to 50 ps for 00 ps- as one species ground 0.0 state 0 ps 5 ps 0 ps 5 ps 0 ps 50 ps 00 ps excited state contribution 45 % 49 % 44% 3 % 6 % 6 % 0 % wavenumber (cm - ) 9

30 ground state 5 ps 7.5 ps 0 ps BR ps 5 ps 7.5 ps Z Axis 0 ps wavenumbers (cm - ) 30

31 Table Vibrational dephasing rates characterized by the band widths of the C=C and C3=C4 stretching modes for the for BR 5. and BR 5.3 compared to the vibrational dephasing rates for their T 5. and T 5.3 intermediates BR-5. ground state T 5. BR-5.3 ground state T 53 3 Maximum position peak [cm - ] C=C C 3 =C 4 Band width (FWHF) [cm - ] Maximum position peak [cm - ] Band width (FWHF) [cm - ]

32 Rel. PTR/CARS intensity GS -5ps 5ps 7.5ps 0ps.5ps 5ps 7.5ps 0ps.5ps 5ps 30ps 3-0. BR5.3 07/9/ Raman Shift (cm - ) 3

33 Table 3 Vibrational dephasing rates characterized by the band widths of the C=C and C3=C4 stretching modes for the for BR 5.3 as a function of time delay Time delay [ps] Band width (FWHH) [cm - ] Maximum peak position [cm - ] C=C C 3 =C 4 C=C C 3 =C

34 What information about vibrational dynamics is contained in the CARS band shape? 34 34

35 Maxwell equation r ( E ( r, t )) E + = 4 c t c π t P r r r r density P, =, ρ r ( ) P r t () t ( r t ) T ( ) operator 35 35

36 3 ρ t = i h [ H() t, ρ] H ( t) = H ρ( ρ0 0 ( ) t) = exp iht ρ = ρ 0 + ρ () + ρ () + ρ (3) + K P 3 ; S (3) ( t ); χ (3) ( ω ) 36 36

37 4 Time domain response S CARS (3) (,, ) ~ S t t t 3 5 four time correlation functions 37 S (3) ( t ) V ( t ) V ( t ) V ( 0) ( t) V 3 factorization of the V ( t) V (0) Green functions two time correlation functions 37

38 where µ Q Q V = µ E α Q Q 38 38

39 6 frequency domain response S CARS (3) (,,, ) ~ χ ω ω ω ω s factorization ( ω ) I( ) I( ) I s ω ω 3 39 ( ) ω ω + Γ α Q (0) α ( t Q ) vibrational correlation function Q(0) Q( t) 39

40 7 8 Γ = Q = Q i ( ω( t )) t iω t Q = Q e e 0 πct band width 0 0 e i( ω + ( t ))t t 0 ω vibrational dephasing cumulant expansion ( t ') i ω( 0) ω dt' e 0 T ( ) + = T γ pure dephasing life time 40 40

41 9 ω( 0) ω( t ) 0 h ω(t) = h ( H H ) 00 H = H H V 0 + bath + bath is included in 4 the reduced density operator model 4

42 Model of vibrational dephasing Torsional coupling 4 4

43 43 L K K K L K L K K K K K er Q Q G G Q FQ Q Q Q Q V QK VQ Q Q V V int + + = + + = = = = = = = = N i N i N i N j N i N j j i ij j i ij i ii i ii q F q p p G F q p G H 0 ) ( cos ) ( q fq q q F p p g p p G H = φ 43

44 ω 0 cos 0 ± GF + g f φ ± cos g F φ + GF ω + ( δφ( )) ( t) = ω0 + ωδφ( t) + ω t ( Γ ) ( ) ac = τc ac i i ω 44 44

45 ( τ ) c and ac i ω = = 0 ω φ δφ( t) δφ(0) ac δφ i ( φ ) ( ) ( ) Γ = ω τ bd bd i for the ground state Γ ac = c ( ) ( ) Γ + Γ + ( γ + γ ) ac for the excited state int er ac ( ) ( ) ) i i Γ = Γ prof. Halina Abramczyk + Γ Laboratory + of ( γ b + γ d bd bd Laser Molecular Spectroscopy bd Technical i int er 0 a c

46 BR-570 J-65 K-590 Raman Shift ( cm - ) 46 Rel. CARS Intensity

47 Raman Shift [ cm - ] Rel. CARS Intensity C=C Stretch C=N Stretch BR6. J6. K6. 47

48 ground state 5 ps 7.5 ps 0 ps.5 ps BR ps 7.5 ps 0 ps wavenumbers (cm - ) 48 48

49 Electronic dynamics of BR and its modified analogs 49 49

50 T.Ye, N.Friedman, Y.Gat, G.H.Atkinson, M.Sheves, M.Ottolenghi, S.Ruhman, J. Phys. Chem. B, Vol. 03, No. 4, 999 Transient spectral changes following excitation of native, all-trans, br (br 570 ). Time values represent the delay between zero time, determined as described in the text and the probe pulse. Top: fast time scale; bottom: slower time scale. Insets enlarge the vertical scale of the intermediate region, where the DOD values are relatively small. Data points are missing around the interfering 60nm excitation wavelength

51 T.Ye, N.Friedman, Y.Gat, G.H.Atkinson, M.Sheves, M.Ottolenghi, S.Ruhman, J. Phys. Chem. B, Vol. 03, No. 4, Transient spectral changes following excitation of C3C4, all-locked bacteriorhodopsin, br 5.. Details as in earlier figure. 5

52 Models -state model 3-state model S(A) g S(B) u H 00-00fs I H fs I A g 500fs J S(B) u Energy S(A) 0 g hν 700nm 860nm 500fs 65nm J Energy FL S(A) 0 g BR trans K 3-cis BR trans K 3-cis C 3=C 4 torsional coordinate C 3=C 4 torsional coordinate 5 5

53 Unanswered questions why the femtosecond spectra of native BR-568 and locked analogs are identical? why the stimulated emission spectrum does not overlap with the spontaneous fluorescence? 53 53

54 Linear and nonlinear responses Vibrational coupling Theoretical model 54 54

55 55 ( ) ( ) ( ) ( ) t M M dte kt I t i exp + + = ω ω π ω h [ ] )],, ( ),, ( [ )],, ( ),, ( [ ) ( ) ( ) ( ) ( ) ( t t R t t R e t t R t t R e dt dt S H H t t t i t i H H t t t i t i HB τ τ τ τ ω ω ω ω τ χ ω ω χ ω ω = + + h 55

56 Hole burning profiles 56 56

57 57 extinction coefficient [mol - cm 3 cm - ] bleach of the ground state BR-568 nm (300 cm - ) J-65 photoproduct absorption HOOP (800 cm - ) near IR stimulated emission CH 3 rock (000cm - ) wavelength (nm) C=C (530 cm - ) 57

58 Conclusions Proposed mechanism of primary events in BR photocycle 58 58

59 S n 460 nm 640 nm S 568 nm H C=C B HOOP B torsion Pump [nm] 60 [] 65 [6] 68 [] S 0 A 860 nm BR-568 all-trans I H and I species all-trans A SE C = C 658 nm J-65 all-trans J 568 nm SE HOOP SE torsion 730 nm Equilibriated BR in the excited state all-trans photoisomerization K 3-cis 605 nm K fs 500fs 3.5ps t 59