SKKU-EMBO conferenceJUNE 25, 2016

Minhaeng ChoIBS 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 complexOLD PARADIGM: STRUCTURE

NEW PARADIGM: DYNAMICS

Femtosecond 2-Dimensional Vibrational/Electronic Spectroscopy

Brief historical accountsNonlinear 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

CH

CH3

C

O

N

H

C C

H H Nuclear spin 2Nuclear spin 1

J

J

COSY-NMR NOESY-NMR Connectivity between different atoms

Coherent 2D vib. Spectroscopy Connectivity between

different vibrational chromophores (groups)

2D

NM

R2D

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 & INFORMATION2D 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 tt

0ˆ ˆ ˆ( ) ( ) ( )IH t H t H t

00( , ) exp ( )

t

t

iV t t d L

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

+=

+= + +

+= + + + + + +

(t0)P(3)(t) = < >NM. Cho, Two-Dimensional Optical Spectroscopy (CRC, 2009)

Signal

field ELO

Esig+ELO

Sample

js

XY

Z

T

j1

j2

j3

k2

k3

k1

k2 k3k1 LO Half-wave Plate

PolarizerBeam SplitterMirror

tr

MCT Array

Detectorfs IR

pulse

S

Polarization-Angle-Scanning 2D Spectroscopy

τ T t

i t

t

e

ω

g

e t e i t

t e tωg e

g

e

ρ t ABSORPTION

FREQUENCY

EMISSION

FREQUENCY

t

SIGNAL

Recovered

from Experiment

3( , , )S T t

Time

Coherent 2D Optical SpectroscopySpectral interferometry for heterodyne-detection

τ T t

i t

t

e

ω

g

e t e i t

t e tωg e

g

e

ρ t Excitation

Frequency

Emission

Frequency

t

SIGNAL

Recovered

from Experiment

3( , , )S T t

Time

Coherent 2D Optical SpectroscopySpectral 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 tT, t ; t0

2D ELECTRONIC SPECTROSCOPY

Two coupled oscillators (Q1 & Q2)

FT2

2 1 1 1( ) ( ) ( ) (0)t t t t

2D SPECTROSCOPY

21

1 2( , ; )I Time

t1t2

2-D spectrum

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

COUPLING CROSS PEAKS!?

Negatively

Correlated

Spectral

MotionPositively

Correlated

Spectral

Motion0j k

0j k

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

1

2

3

4

56

7

1234567

ExcitonLevel

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

of 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

CH3H3C

H

O

Me

O

H Me

C

O

N

H

CH3H3C

H

O

Me

H

O

Me

O

H Me

CH3-CN

CHCl3

+ −

+ −

Ion pairing dynamicsubiquitin 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

0.02

1/2c(cm

-1)

3/2c(c

m-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 2sinkj k j jkS

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 BZ or BA transitions in real time?

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

2.9Å 3.4Å4.1Å

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) SpectroscopyElectric 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 activityA 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 rotation1. 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

optical rotation

OR

DC

DO

RD

+ C

D

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 22

2 2 2 2

1 4( , ) ( , ) ( , )z t z t z t

c t c t

E E P

2 22

||2 2 2 2

0 0

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

2 2

t t

xx xx

m

iN NE z t E z t d t E z d t E z

c t c t V V

( , )E z tFor , 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 mR

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

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

0

0

1( ) ( )

2 2E E B BC

0

2B E E B

*0 Im2

E B

*4Im( ) ImA 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

1

2

3

4

Face-to-Face Dimer

Tetramer1

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 ˆN

l

l

H H V

1 21 2

12

ˆ ˆ( ) ( )1ˆ2

N Nl m

l m l

V d dr

r r

r r

(1 ) (1 , )lm lm l lm lmH E V l m N

Electronic coupling constant

1 21 2

12

( ) ( )eg ge

l mlmV d d

r

r rr 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

(M

ea

sure

d )

600

300

0

- 300

- 600

6000

3000

0

- 3000

- 6000

CD

(Calc

ula

ted )

400 450 500 550

Experimental

TDDFT/CAM-B3LYP

Frenkel Exciton x3

200

0

OR

D (

Measure

d )

- 400

- 200

Wavelength (nm)

500 550 600 650 700

400 450 500 550

2000

0

- 4000

- 2000

OR

D (C

alc

ula

ted )

Experimental

TDDFT/CAM-B3LYP

Frenkel Exciton x3

23000

22000

21000

20000

19000

18000

17000

16000

15000

0

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

0

0

ˆIm 0 0( )

V

K

K

eR K K m

E E m

Numerical Simulations:

CD and ORD spectra

2 20 0

2 20 0

( ) ( )

2 20 00

0 0 0

( ) ( ) ( )

2erfc erfc

3 2 2

K K

K K

L R

K KK

K K K K

iR 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)

*0 Im2

C

E B2

0 0 /CPLC E c

Double Fishnet Negative-Index Metamaterial

/ CPLC C

Distributions of Elec. And Mag. Fields, and

Enhancement Factor

Top view

Side view

1s

tm

ag

neti

c r

eso

nan

ce

at

892 n

m

2n

dm

ag

ne

tic r

eso

nan

ce

at

682 n

m

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

of 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.

WHAT IS NEXT?

Optical Activity (Chiroptical) Spectroscopy (Sensitive to Molecular Chirality)

+

Multi-Dimensional Optical Spectroscopy(Enhanced Spectral and Time Resolution)

Multi-Dimensional Chiroptical Spectroscopy2D 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

spectr

a

Frequency (cm-1)

Experiment

7

6

5

4

3

2

1

76

5

4

3

2

1

Absorp

tion

6 K

77 K

1

2

3

4

56

7

1234567

Exciton Level

Fenna-Matthews-Olson

LH protein complex

12000 12350 12700 1 ( )cm

2D photon echo

spectrum of FMO light-

harvesting complex

(Experimentally Measured)

Absorption

Abso

rpti

on

t

Tw = 1 ps

12000 12350 12700 1 ( )cm

t

A

B

2D Circularly polarized

photon echo

spectrum (No experiment yet)

Abso

rpti

on

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

overtone 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