Eadweard Muybridge (1887) U LTIMATE G OAL Spectroscopy for M - - PowerPoint PPT Presentation

SKKU-EMBO conference

JUNE 25, 2016

Minhaeng Cho

IBS Center for Molecular Spectroscopy and Dynamics (CMSD), Department of Chemistry, Korea University

APPLICATIONS OF COHERENT MULTIDIMENSIONAL SPECTROSCOPY

SCIENTIFIC REVOLUTION & PARADIGM SHIFT

Scientific Developments

Theoretical Experimental

 Newton’s Mechanics  Quantum Mechanics  The theory of evolution  X-ray diffraction  Nuclear magnetic

resonance (NMR)

 LASER (MASER)  Novel concepts  Different and generalized

viewpoints

 Novel tools  Observations of

the unseen  Freeman Dyson (1923 ~) Physicist

• Inst. for Advanced

Study (IAS,Princeton)

A Novel Experimental Tool! Multi-dimensional optical and chiral spectroscopy

SPECTROSCOPY

Electromagnetic Wave Amplitude (Intensity), Frequency, and Phase Field-Matter Interaction-Induced Changes in EMW Properties Structure and Dynamics of Complex Molecular Systems

“SEEING IS BELIEVING”

Eadweard Muybridge (1887)

“The movements of participants in molecular dramas can be recorded in vivid detail, using coherent multidimensional spectroscopy”

ULTIMATE GOAL

Spectroscopy for “MOLECULAR MOTION PICTURE”

Femtosecond (10-15 s) multidimensional vibrational/electronic spectroscopy

TWO TECHNICAL DIFFICULTIES!

ULTRASMALL (10-10 m) AND(!) ULTRAFAST (10-15 s)

HOW TO OVERCOME

ULTRAHIGH SPATIAL RESOLUTION AND(!) ULTRAFAST TIME-RESOLUTION

 Researchers use a variety of tools to probe protein function and interactions, with drug discovery the major goal  One of seven research fields in 21C “Large-scale protein folding and 3-D structure studies” X-ray crystallo- graphy 2D-NMR Advantages Restrictions High spatial (atomic) resolution Solution sample Molecular crystal & Low time- resolution Low time- resolution

Protein Structure Determination: Conventional Tools Advantage and Limitation

Cho and coworkers, Phys Chem Chem Phys (review) 10, 3839 (2008)

2D CP-PE spectrum of FMO light-harvesting protein complex

OLD PARADIGM: STRUCTURE NEW PARADIGM: DYNAMICS

Femtosecond 2-Dimensional Vibrational/Electronic Spectroscopy

Brief historical accounts

Nonlinear optical spectroscopy: Long history since Bloembergen, Shen,… 4WM: Ippen, Shank, Fleming, Wiersma, Warren, Albrecht, Mukamel, Skinner, Cho, etc.

In 1981, Warren, W. S.; Zewail, A. H., Optical analogs of NMR phase coherent multiple pulse spectroscopy,

• J. Chem. Phys. 75, 5956–5958 (1981). 2D optical spectroscopy alluded but unsuccessful (long (>ps) pulse)
• 1. Fifth-order nonlinear optical spectroscopy (two (elec. or vib.) coherence evolutions)

Fifth-order electronic spectroscopy: Cho & Fleming, J. Phys. Chem. (1994) Fifth-order Raman (vibrational) spectroscopy: Tanimura & Mukamel, J. Chem. Phys. (1993) Complicated due to undesired contributions and weak signals. Not successful

• 2. Electronic (vis) (photon echo) four-wave mixing spectroscopy

Spectral interferometry of photon echo: Jonas, Chem. Phys. Lett (1998) 2D elec. spectroscopy of photo-synthetic complex: Cho, Fleming et al, Nature (2005)

• 3. 2D IR-vis four-wave-mixing spectroscopy (vibrational + electronic)

2D IR-IR-vis spectroscopy: Cho, J. Chem. Phys. (1998) (theoretical) DOVE-IR: Wright, J. Am. Chem. Soc. (1999) (experimental)

• 4. IR four-wave mixing spectroscopy (Vibrational)

IR photon echo: Fayer & coworkers (1993) etc. (using a free electron laser) 2D IR pump-probe: Hamm, Lim, & Hochstrasser, J. Phys. Chem. (1998) Experiments: Hochstrasser, Hamm, Tokmakoff, Zanni, etc. Theory: Cho, Mukamel, Skinner, Jansen, Knoester, Stock,etc. Cho, Two-dimensional optical spectroscopy, CRC press (2009)

Q1-mode Q2-mode Vibrational energy relaxation (dissipation) Vibrational phase relaxation (dephasing) Vibrational coupling

C O H N Q1 Q2

C O N H CH CH3 C O N H C C H H

Nuclear spin 2 Nuclear spin 1

J

J

COSY-NMR NOESY-NMR Connectivity between different atoms Coherent 2D vib. Spectroscopy Connectivity between different vibrational chromophores (groups)

2D NMR 2D Vib. Spec. 2D NMR & 2D Vibrational Spectroscopy Vibrational coupling versus Spin-spin coupling

• M. Cho, “Coherent 2D Optical Spectroscopy” Chem. Rev. (2008)
• M. Cho, “Two-Dimensional Vibrational Spectroscopy”, in Adv. Multi-photon Processes

and Spectroscopy, vol.12, page 229 (1999) (Review Article)

Why coherent multidimensional (IR, Raman, electronic, IR-vis, etc.) spectroscopy?

• M. Cho, “Coherent 2D Optical Spectroscopy” Chem. Rev. (2008)

1.TIME RESOLUTION

~10-15 (2D optical spect.) vs ~10-6 (2D NMR)

• 2. NUMBER OF OBSERVABLES (PEAKS)

~ N (1D) ~ N2 (2D) ~ Nd (d-dimensional spectroscopy)

• 3. THE SMALL IS CRUCIAL!

OBSERVABLES & INFORMATION

2D OPTICAL (VIB./ELEC.) SPECTROSCOPY

• 1. Measurements of angles() between two different

transition (electric and/or magnetic) dipoles  (Chiral or achiral) Molecular Structure

• 2. Measurements of frequency random jumps between

discrete states induced by chemical exchange processes  Chemical Kinetics

• 3. Measurements of population or coherence transfers

by electronic couplings  State-to-state quantum transition & connectivity

• M. Cho, Two-Dimensional Optical Spectroscopy, CRC press (Taylor&Francis), 2009

Definition of density operator Quantum mechanical Liouville equation Hamiltonian consisting of zero-order (mol.+rad.) and perturbation (rad.-mol. interaction) term Time-evolution operator in Liouville space (time-dependent perturbation theory) Third-order polarization induced by nonlinear (3rd-order) radiation-matter interactions

TIME-DOMAIN NONLINEAR SPECTROSCOPY: Theoretical Consideration

( ) | ( ) ( ) | t t t      ˆ ( ) [ ( ), ( )] ( ) ( ) i i t H t t L t t t          ˆ ˆ ˆ ( ) ( ) ( )

I

H t H t H t  

( , ) exp ( )

t t

i V t t d L  



        



+ = |m><n| |m><n| |m><n| = |m><n|

• |m><n|

+ = + = + +

+ = + + + + + +

ˆ 

(t0) P(3)(t) =

< >

N

• M. Cho, Two-Dimensional Optical Spectroscopy (CRC, 2009)

Signal field

ELO Esig+ELO

Sample

js

X Y Z

T  j1 j2 j3 k2 k3 k1

k2 k3 k1 LO Half-wave Plate Polarizer Beam Splitter Mirror tr MCT Array Detector

fs IR pulse

S

Polarization-Angle-Scanning 2D Spectroscopy

τ

T

t

 

i t

t e

 



  

ω

g e

 

t   e

 

i t

t e  



  

t

ω

g e

g

e

 

ρ t

ABSORPTION FREQUENCY EMISSION FREQUENCY





t



SIGNAL Recovered from Experiment

 

3 ( , , )

S T t 

Time

Coherent 2D Optical Spectroscopy

Spectral interferometry for heterodyne-detection

τ

T

t

 

i t

t e

 



  

ω

g e

 

t   e

 

i t

t e  



  

t

ω

g e

g

e

 

ρ t

Excitation Frequency Emission Frequency





t



SIGNAL Recovered from Experiment

 

3 ( , , )

S T t 

Time

Coherent 2D Optical Spectroscopy

Spectral interferometry for heterodyne-detection

 

t g  

Shutter Speed Exposure Time

Time-resolved two-dimensional spectroscopy is useful to measure correlation between two observables, e.g., transition frequencies, separated in time, which in turn provide information on spatial connectivity between chromophores, i.e., structure, and coupling.  ; t0 tT, t ; t0

2D ELECTRONIC SPECTROSCOPY

Two coupled oscillators (Q1 & Q2)

FT2

2 1 1 1

( ) ( ) ( ) (0) t t t t     

2D SPECTROSCOPY

2 1

1 2

( , ; ) I   Time

t1 t2 2-D spectrum

Jeon et al, Acc. Chem. Res. (2009)

COUPLING CROSS PEAKS!?

Negatively Correlated Spectral Motion Positively Correlated Spectral Motion

j k

  

j k

  

FMO (Fenna-Matthews-Olson) Photosynthetic Complex (CMC2)

1 2 3 4 5 6 7

Allen and coworkers

• J. Mol. Biol. (1997)

271, 456±471 A model of the position of the cofactors of the BChl a protein and reaction center in the cell membrane.

Diagonal peaks GB+SE with Gjj(T)

QUANTUM INTERFERENCE

Off-diagonal peaks GB Off-diagonal peaks SE with Gjk(T) Off-diagonal peaks EA with Gjj(T) Off-diagonal peaks EA with Gjk(T) Total spectrum at T=1000 fs

(+) (+) (+) (-) (-)

(d) (e) (f) (a) (b) (c)

 (cm-1)  (cm-1)

Diagonal peaks GB+SE with Gjj(T)

QUANTUM INTERFERENCE

Off-diagonal peaks GB Off-diagonal peaks SE with Gjk(T) Off-diagonal peaks EA with Gjj(T) Off-diagonal peaks EA with Gjk(T) Total spectrum at T=1000 fs

(+) (+) (+) (-) (-)

(d) (e) (f) (a) (b) (c)

 (cm-1)  (cm-1)

Numerically simulated 2D spectra

 t

 (cm-1)  (cm-1)

Two-dimensional spectroscopy

• f electronic couplings in

photosynthesis

100 fs < Waiting Time (T) < 2000 fs

Time 100 fs 200 fs 300 fs 600 fs 1000 fs

COUPLINGS  Ex. TRANSFER

Nature 434, 625 (2005)

WHAT DID WE LEARN FROM 2D ELECTRONIC SPECTROSCOPY OF FMO LIGHT-HARVESTING COMPLEX?

• 1. Demonstration of how electronic couplings within molecular complexes can be made

visible directly by measuring 2D femtosecond photon-echo spectra (Amplitudes of cross peaks)

• 2. Development of a self-consistent theory for nonlinear spectroscopy and excitation

transport (Energy transport through space with tens of nanometer spatial resolution and femtosecond temporal resolution)

• 3. Mechanism of energy relaxation processes in FMO photosynthetic complex

STRUCTURE AND DYNAMICS 2D vibrational or electronic spectroscopy

C O N H CH3 H3C H O Me O H Me C O N H CH3 H3C H O Me H O Me O H Me

CH3-CN CHCl3

+ − + −

Ion pairing dynamics ubiquitin FMO complex hairpin

-sheet polypeptides

Hahn et al., J. Chem. Phys. 123, 84905 (2005)

Anti-parallel and prallel -sheets:

spectroscopically distinguishable?

Hahn, et al. J. Chem. Phys. 123, 84905 (2005)

1620 1660 1700 1620 1660 1700 1620 1660 1700

• 0.02

0.02

1/2c(cm

• 1)

3/2c(cm

• 1)

C O N H C O N H C O N H C O N H C O N H C O N H C O N H C O N H C O N H C O N H C O N H C O N H Antiparallel -Sheet

C O N H C O N H C O N H C O N H C O N H C O N H C O N H C O N H C O N H C O N H C O N H C O N H

Parallel -Sheet

2 2 2

sin

kj k j jk

S    

2D Difference Spectrum ZZZZ-3ZXXZ Cross peak intensity

Amyloid Aggregate Structure?

Middleton et al. Nature Chem. (2012)

• M. Cho, Nature Chem. 4, 339 (2012)

Various DNA double helical structures

Spectroscopic probing of BZ or BA transitions in real time?

(a) A-DNA : (GC)3 (b) B-DNA : (GC)3 (c) A-DNA : (GC)4

2.9Å 3.4Å 4.1Å 3.5Å

A-DNA B-DNA Z-DNA

Lee et al. J. Chem. Phys. 126, 145102 (2007)

1D and 2D IR spectra of (GC)n

(numerical simulation results)

(a)

ωt

(b)

ωt

(c)

ωτ ωt

A-DNA B-DNA Z-DNA

• 1. C. Lee et al. J. Chem. Phys. 125, 114508 (2006)
• 2. C. Lee et al. J. Chem. Phys. 125, 114509 (2006)
• 3. C. Lee et al. J. Chem. Phys. 125, 114510 (2006)
• 4. C. Lee et al. J. Chem. Phys. 126, 145102 (2007)

IR PROBE + time-RESOLVED IR SPECTROSCOPY

Linear (Chiroptical) Spectroscopy Electric Field Approach

HANDEDNESS IN NATURE

Molecular Chirality in Motion

CHIRAL AMINO ACIDS:

Building blocks of proteins

Myoglobin NTL-9 Met1Aha NTL-9 Ile4Aha

BIOMOLECULES ARE INTRINSICALLY CHIRAL

Chiral molecules: Optical activity

A chiral molecule is a type of molecule that lacks an internal plane of symmetry and thus has a non-superimposable mirror image.

FMO Complex PROTEINS OF INTEREST

Optical Rotation

j

Optical rotatory dispersion (ORD) measurement

Linear Polarizer Chiral Sample Detector

A brief historical account on optical rotation

• 1. 1811. F. J. D. Arago (French physicist). Optical Rotation (OR) in quartz
• 2. 1811. J. B. Biot. OR in liquids (turpentine, an organic substance)
• 3. 1822. J. F. W. Herschel (English astronomer). OR in two forms of quartz
• 4. 1822~. Polarimeter for OR measurement, e.g., glucose concentration
• 5. 1849. Louis Pasteur. OR measurements of two forms of tartaric acid crystals.

 two different structures (optical isomers!)

• 6. 1874. J. H. van’t Hoff and J. A. Le Bel. Chemical bonds between C-atom and

neighbors  tetrahedral structure  three-dimensional nature of molecules

Analyzer

( ) j  

frequency-dependent

• ptical rotation

ORD CD ORD + CD

ORD measures difference in birefringence for LCP and RCP fields passing through chiral medium CD measures difference in absorption of LCP and RCP fields by chiral molecules Optical activity of chiral molecular systems refers to both ORD and CD, which are related to each other via Kramers-Kronig relation. INCIDENT TRANSMITTED

nLCP ≠ nRCP κLCP ≠ κRCP

femtosecond Linear Chiroptical Activity Measurement Chiral spectroscopy

Conventional approach: Differential absorption measurement using left- and right-handed helical (Left- and Right-CP) E-fields In 2005, I had a series of questions that are….

Background noise problem A/A ~ 10-3 – 10-6

Q) Is it always necessary to use chiral (left- or right-handed) fields to characterize molecular chirality? (Traditional Approach based on Intensity Mesurement) A) Not necessarily Q) Then, how is it possible to characterize certain handed molecule with non-chiral field? A) Spectrometer or detection scheme should be chiral! (New Approach based on Phase-Amplitude Measurement) Q) Can a femtosecond linearly polarized pulse (non-chiral field) be used to determine molecular chirality? A) Yes!

Vertical LP (VLP) Horizontal LP (HLP) Transverse EM wave: Two linear polarization states of electric field (E-field)

VLP and HLP of the transverse E-field propagating in a vacuum or an isotropic medium with achiral molecules are UNCOUPLED! (from Maxwell equation) e.g., VLP into a glass of water, VLP out with zero HLP Q) What happens when VLP passes through a sugar solution?

VLPin |HLPout|2/|VLPout|2 = 10-4 k

HLPout is generated by the radiation-matter interaction of chiral molecules with VLPin.  VLP and HLP become COUPLED! (from Maxwell equation) (A Cause-and-Effect phenomenon)  What are the cause and the effect in this case? Cause: Magnetic field-magnetic dipole interaction Effect: Electric field-electric dipole interaction-induced E-field  What is the connection (linear response) function?

Chiral Solution E(t) B(t)

How to separately measure HLP (E) and VLP(EII) electric fields?

After solving the coupled Maxwell equation, which is

2 2 2 2 2 2 2

1 4 ( , ) ( , ) ( , ) z t z t z t c t c t         E E P

2 2 2 || 2 2 2 2

1 4 ( , ) ( , ) ( ) ( , ) ( ) ( , ) 2 2

t t xx xx m

iN N E z t E z t d t E z d t E z c t c t V V

 

        

  

                            

 

( , ) E z t



For , we have a coupled differential equation:

Rhee et al. J. Chem. Phys (2008)

Determination of absolute CD and ORD values

CHIRAL susceptibility is a complex function, and

( ) ( ) ( )

L R

        

' "

( ) ( ) i        

circular birefringence (CB)

'

2 ( ) ( ) ( ) n n        

''

4 ( ) ( ) ( )

a

n c         

circular birefringence (ORD) differential absorption coefficient (CD) circular dichroism (CD)

||

( ) ) ( ) ( E E    



 

THEN, HOW TO MEASURE COMPLEX ELECTRIC FIELD SPECTRUM?

• 1. Electric field amplitude E versus intensity |E|2
• 2. QM Wavefunction  versus probability ||2

PHASE, PHASE, PHASE!

Experimental setup: Single-Shot Electronic CD/ORD Ultimate sensitivity: Single pulse measurement!

For the success of ultrasensitive measurements (1) Quasi-null (perpendicular polarizer) geometry (2) Heterodyne detection (3) Self-referencing technique

Phase and Amplitude Measurements

Mach-Zehnder Interferometry

What are experimentally measured?  Spectral interferogram (interference signal between signal E and reference E and

( ) S 



|| ( )

S 

Rhee et al, Nature (2009), JOSA (2009), ChemPhysChem (2010)

WHAT IS THE UNDERLYING PRINCIPLE?

( ) E 



|| ( )

E 

and Well-known transformation

THOMAS YOUNG’S EXPERIMENT

MODIFICATION OF YOUNG’S DOUBLE-SLIT EXPERIMENT! What if a chiral molecule is placed at one of the two slits?

||

( ) ) ( ) ( E E    



 

Molecular Chirality versus Optical Chirality

Molecular Chirality, Optical Activity and Rotatory Strength

Im( ) μ m R  

Q) What is the corresponding (chiral) property of electromagnetic field?

Optical Chirality (initially considered by Lipkin (1960’s) as one of Zilches

1 ( ) ( ) 2 2 E E B B C        

 

2 B E E B      

 

*

Im 2 E B     

 

*

4Im( )Im A A A

 

      μ m E B

Q) What is the difference in the rates of absorption with (+) and (-)-handed electromagnetic fields?

Single-shot Electronic Optical Activity Interferometry

DNA-templated helical cyanine dye assembly

Face-to-Face Dimer Tetramer 1 2 3 4

ips = 3.6 Å shift = 2.4 Å dist = 18.5 Å

Induced Optical Activity of DNA-Templated Cyanine Dye Aggregates: Exciton Coupling Theory and TD-DFT Studies Classical MD simulation

Initial Structure: NUCGEN routine in AMBER Force Field: ff09 + TIP3P (300K) Equilibration: 5 ns NVT Simulation: 20 ns NPT

QM calculation

Induced Optical Activity of DNA-Templated Cyanine Dye Aggregates

• 1. TD-DFT Calculation Results

TD-DFT

Functional (nm) (nm) (nm) B3LYP 478 (-3214) 506 (4856)

• 29

CAM-B3LYP 458 (-4054) 490 (4011) 517 (564) 32 PBE0 469 (-3588) 497 (4820)

• 28

LC-ωPBEh 451 (-2702) 484 (4071)

• 33

M05-2X 458 (-4325) 481 (4232) 520 (608) 23 M06-2X 467 (-3453) 490 (5153) 532 (510) 24

Experimental 588 607 ~670 19

1

 

1

 

2

    (tetramer)

• 2. Exciton coupling theory

1

ˆ ˆ ˆ

N l l

H H V



 



1 2 1 2 12

ˆ ˆ ( ) ( ) 1 ˆ 2

N N l m l m l

V d d r  



 



r r r r (1 ) (1 , )

lm lm l lm lm

H E V l m N        

Electronic coupling constant

1 2 1 2 12

( ) ( )

eg ge l m lm

V d d r    



r r r r

HOMO LUMO

1 2 3 4

V13 = V24: Face-to-Face Coupling

Coupling constants (cm-1): TDC, TrESP and FED methods

Basis sets used: 6-311++G(2df,2pd) (6-31+G(d,p))

Wavelength (nm)

500 550 600 650 700

CD (Measured )

600 300

• 300
• 600

6000 3000

• 3000
• 6000

CD (Calculated )

400 450 500 550

Experimental TDDFT/CAM-B3LYP Frenkel Exciton x3

200

ORD (Measured )

• 400
• 200

Wavelength (nm)

500 550 600 650 700 400 450 500 550 2000

• 4000
• 2000

ORD (Calculated )

Experimental TDDFT/CAM-B3LYP Frenkel Exciton x3

23000 22000 21000 20000 19000 18000 17000 16000 15000 H1 → L1 H1‒H3 → L1‒L3 450 550 600 500 650 H → L H1‒H3 → L1+L3 H1 → L1 H1+H3 → L1‒L3 H3 → L3 H3 → L3 H2+H4 → L2‒L4 H2+H4 → L2+L4 Monomer Dimer Tetramer H2‒H4 → L2‒L4 H1‒H3 → L1+L3 H2‒H4 → L2+L4

2

ˆ Im ( )

V K K

e R K K m E E m        

Numerical Simulations: CD and ORD spectra

( ) ( ) 2 2

( ) ( ) ( ) 2 erfc erfc 3 2 2

L R K K K K K K K

i R e i e i

   

          

     

                                   



NANOSCALE METAMATERIAL-ASSISTED CHIROPTICAL SPECTROSCOPY Globally Enhanced Chiral Field Generation by Negative-Index Metamaterials

Yoo et al., Phys. Rev. B 89, 161505 (2014)

*

Im 2 C          E B

2 0 / CPL

C E c   

Double Fishnet Negative-Index Metamaterial

/

CPL

C C  

Distributions of Elec. And Mag. Fields, and Enhancement Factor

Top view Side view 1st magnetic resonance at 892 nm 2nd magnetic resonance at 682 nm Top view Side view Enhancement Factor

Volume-Averaged Optical Chirality: Size-dependence

Yoo et al., Phys. Rev. B 89, 161505 (2014) Non-chiral negative-index metamaterials can be used to generate the enhanced chiral fields via simultaneous excitation

• f electric and magnetic fields in the

longitudinal direction.  Useful chiroptical spectroscopy The bridging of chiroptical spectroscopy and photonic metamaterials, two distinct disciplines of optics, will offer new possibilities for applications of negative- index metamaterials in the future.

WHA WHAT T IS IS NEXT? NEXT?

Optical Activity (Chiroptical) Spectroscopy

(Sensitive to Molecular Chirality)

+ Multi-Dimensional Optical Spectroscopy

(Enhanced Spectral and Time Resolution)

Multi-Dimensional Chiroptical Spectroscopy

2D Circular Dichroism? 2D Optical Rotatory Dispersion? 2D Raman Optical Activity?

Circularly polarized photon echo Nonlinear optical activity (CD or ORD) spectroscopy

τ

T

t

SIGNAL

Time

Conventional (linearly polarized) photon echo

R L

Z Z Z Z Z Z Z

SZZZZ SLZZZ

Z Z Z

SRZZZ S=SLZZZ-SRZZZ

12000 12300 12600

CD spectra

Frequency (cm

• 1)

Experiment

7 6 5 4 3 2 1 7 6 5 4 3 2 1

Absorption

6 K 77 K

1 2 3 4 5 6 7

Fenna-Matthews-Olson LH protein complex

12000 12350 12700

1

( ) cm







2D photon echo spectrum of FMO light- harvesting complex

(Experimentally Measured)

Absorption Absorption

t



T

w = 1 ps

12000 12350 12700

1

( ) cm







t



A B

2D Circularly polarized photon echo spectrum

(No experiment yet)

Absorption Circular dichroism

Choi et al. PCCP (2008) Cho et al. J. Phys. Chem. B (2005) and Nature 434, 625(2005)

Cho, Two-dimensional optical spectroscopy, CRC press (2009)

Circularly Polarized Sum-Frequency- Generation

• J. Chem. Phys.

116, 1562 (2002) 2D Circularly Polarized Pump-Probe (2D CP-PP) (Nonlinear CD and ORD)

• J. Chem. Phys.

119, 7003 (2003) 2D Circularly Polarized Photon Echo (JCP 2006 & PCCP 2008) 2D Sum-Frequency- Generation Spectroscopy (Chem Phys 2008) etc…

Theoretical

Nanosecond temperature-jump with an intense IR pulse initiates non- equilibrium relaxation of biomolecules (unfolding/folding), which is monitored by using 2DIR or femtosecond CD (ORD) spectroscopic method Excitation of OD stretch

• vertone band of D2O

= 2.0 m (D2O) → fast energy dissipation → local heating

TEMPERATURE-JUMP 2DIR OR fs-CD PROBE

Probing conformational transition of proteins

HOW TO (T-JUMP)?

TEAM MEMBERS, COLLABORATORS, & ACKNOWLEDGMENTS

RESEARCH FELLOWS

• Dr. Jun-Ho Choi
• Dr. Jonggu Jeon
• Dr. Hochan Lee
• Dr. Kwang-Hee Park
• Dr. Pramod K. Verma
• Dr. Aude Lietard
• Dr. Achintya Kundu
• Dr. Cho-Shuen Hsieh
• Dr. Sreedar Sunku

Former postdoc. and grad. students:

• Dr. I.-T. Eom (Pohang), Dr. S. Kim (Pohang), Joseph Choi (U.Roch.)

COLLABORATORS Hogyu Han(Korea U), Hanju Rhee(KBSI), G. R. Fleming(Berkeley),

• G. Scholes(Toronto), Y. Tanimura (Kyoto), I. Ohmine (IMS), S. Saito(IMS)
• A. Tokmakoff (MIT), J. C. Wright (Wisconsin), S. Mukamel (UC-Irvine),
• G. D. Rose (Johns Hopkins U.), M. D. Fayer (Stanford U.),
• N. Kallenbach(NYU), J. Howell (Rochester U.), L. Barron (Glasgow)

and so on. FUNDS: INSTITUTE FOR BASIC SCIENCE (IBS), KOREA GRADUATE STUDENTS Joo-Yong Lee Michal Maj Bartosz Blasiak Joon-Hyung Lim So-Hee Lim Hyung-Ran Choi

• D. Kossowska

E-Hyun Lee Jun-Young Park Do-Yeon Kim Min-Seok Kim

Thank you