study on the vibrational dynamics of phenol and phenol-water complex by picosecond time- resolved...
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STUDY ON THE VIBRATIONAL DYNAMICS OF STUDY ON THE VIBRATIONAL DYNAMICS OF PHENOL AND PHENOL-WATER COMPLEX BY PHENOL AND PHENOL-WATER COMPLEX BY PICOSECOND TIME-RESOLVED IR-UV PUMP-PROBE PICOSECOND TIME-RESOLVED IR-UV PUMP-PROBE SPECTROSCOPYSPECTROSCOPY
Yasunori Miyazaki, Yoshiya Inokuchi, Takayuki EbataYasunori Miyazaki, Yoshiya Inokuchi, Takayuki Ebata
Department of Chemistry, Graduate school of Science,Department of Chemistry, Graduate school of Science,
Hiroshima UniversityHiroshima University
Vibrational Energy Vibrational Energy RelaxationRelaxation
Intramolecular Vibrational energy Redistribution (IVR)
ls>
lb>
ρ b
Vsb)(
2 2EVk bsbIVR
Fermi’s Golden Rule
= anharmonic coupling
= density of bath state
sbV
b
Vibrational Energy Vibrational Energy RelaxationRelaxation
Intramolecular Vibrational energy Redistribution (IVR)
Anharmonic coupling (normal mode analysis)
ls>
lb>
ρ b
Vsb
...6
1
2
1)(
,,
3
,
2
0
jis
jis jisji
is is
qqqqqq
Vqq
VVqV
jis vvv ,,00,0,
ls>
li>
li>lj>
lj>
Csij
Anharmonic term
Csij = qsqiqj = anharmonic constantEvaluation of coupling amongvibrational modes: s, i, j
)(2 2
EVk bsbIVR
Fermi’s Golden Rule
IR spectrum of phenolIR spectrum of phenol%
tran
smitt
ance
in solutionLarge red-shift•Reduced force constant of the OH bondSpectral broadening•Vibrational Energy Relaxation•Fermi Resonance with overtone and/or combination band•Inhomogeneous broadening due to random geometries
etc
Free OH stretchHydrogen-bonded
OH stretchOH
IR spectrum of phenolIR spectrum of phenol
*T. Ebata, et. al., International Journal of Mass Spectrometry, Vol. 159, pp. 111 (1996).
in supersonic molecular beam*
OH
% tr
ansm
ittan
ce
in solution
Free OH stretchHydrogen-bonded
OH stretch
Experimental SetupExperimental Setup
Supersonic Molecular Beam• Directional (minimizing the Doppler effect)
• Population at the lowest vibrational energy level of S0
• Isolated condition
T O F +c hanneltron
mode- loc kedN d: Y A G laser
T H G
1064 nmsample
P G 401S H
P G 401/ D F G
delay- timec ontrol
IR range2300 - 10000 nm
U V range210 - 440 nm
355 nm
Resolution: 14 ps, 5 cm-1
S 0
O H
S 1
IP
IR
UV
UV
doorwaystate
bathstate
U V
U V UV
UVΔ t
τ 1 τ 2
phenol-dphenol-d00
transient 1+1 REMPI*
U V energy
0O H v' - v''
decay
rise
Energy diagram
Y. Yamada, et. al., J. Chem. Phys., Vol. 120, No. 16, pp. 7400 (2004).
a) OH = 32693 cm-1 b) bath = 35461 cm-1
IR
OH
S 0
O H
S 1
IP
IR
UV
UV
doorwaystate
bathstate
U V
U V UV
UVΔ t
τ 1 τ 2
v'
v''
IR wavenumber (cm-1)3620 3660 3700
νOH = 3656 cm-1
150100500- 50
delaytimeΔ t (ps)
phenol-dphenol-d00
Time Profile
a) OH
b) bath state
U V energy
0O H v' - v''
decay
riseIR
OH
Energy diagram
S 0
O H
S 1
IP
IR
UV
UV
doorwaystate
bathstate
U V
U V UV
UVΔ t
τ 1 τ 2
v'
v''
IR wavenumber (cm-1)3620 3660 3700
νOH = 3656 cm-1
decay τ = 14 ps
rise τ = 14 ps
Summary 1Summary 1
S 0
O H
IR
doorwaystate
bathstate
τ 1 14ps
τ 2<<14ps
densityof state
110state/cm-1
v’IVR1 IVR2
S 1v"
*Petkovic, M. Journal of Physical Chemistry A, Vol. 116, pp. 364-371 (2012)
doorway stateγCH
* bath stateνCH
*
IR
OH
OH
phenol-dphenol-d11
Energy diagram transient 1+1 REMPI
a) OD = 33647 cm-1
b) doorway = 34784 cm-1
IR
OD
33500 34000 34500 35000
S 0
O D
S 1
IP
IR
U V
U V
doorwaystate
bathstate
Δ t
U V U V
U V U V
τ 2
IR wavenumber (cm-1)2660 2700 2740
v'
v''νOD = 2700 cm-1
OD106a
U V energy
0O D v' - v''
decay
risedecaydoorwaystate
phenol-dphenol-d11
Time Profile
U V energy
0O D v' - v''
decay
risedecaydoorwaystate
IROD
IR
OD
Energy diagram
S 0
O D
S 1
IP
IR
U V
U V
doorwaystate
bathstate
Δ t
U V U V
U V U V
τ 2
IR wavenumber (cm-1)2660 2700 2740
v'
v''νOD = 2700 cm-1
O D
doorwaystate
- 100 0 100 200 300delay time Δ t (ps)
Time evolution of existence probability after time t
phenol-dphenol-d11
t
mnmmn
n
t
nn
mnn
eEEt
etOD)
11(2
12
2343
1
2222 cos2)(
t
mnmnmmn
n
t
nn
n
mnn
eEEt
etl)
11(2
1
113
121
23
1
2
2222 cos2)(
OD:
Doorway:
Bath: t
nn
n
etbath 2
123
1
1)(
Fitting parameters*
α1 = 0.616 β21 = 0.323
α2 = 0.663 β22 = 0.353
α3 = 0.424 β23 = -0.911
Assignment of the doorway state l2
116a112118b1
Summary 2Summary 2
Energy gapE13 = 0.656 cm-1
E23 = 0.489 cm-1
E12 = 0.167 cm-1
ODl2l1
2700 cm-1
33647 cm-1
1137 cm-1
34784 cm-1
S0
S1
IR
OD
OD
IVR lifetimeτ2
1 = 80 psτ2
2 = 90 psτ2
3 = 60 ps
Y. Yamada, et. al., J. Chem. Phys., Vol. 121, No. 23, pp. 11530 (2004).
Energy diagram
phenol-dphenol-d11▪▪(D(D22O)O)
ODIRODD
H-bonded νOD = 2600 cm-1
a) OD = 33410 cm-1 b) 34965 cm-1
c) 35211 cm-1
d) 35461 cm-1
U V wavenumber (c m- 1)
33500 34000 34500 35000 35500delay t ime
Δ t (ps )
287
53
20
6.7
transient 1+1 REMPI
S 0
H - bondedO D
S 1
IP
IR
U V
U V
intramolec ularV R
intermolec ularV R
phenol- d1- (D 2O )
phenol- d1 + D 2O
dissoc iation
vibrationalpredissoc iation
U V U V
U V U V
Δ t
τ 1
2560 2600 2640
IR wavenumber (c m- 1)
vO D
τ 2 τ 3
U V energy
0
O D intermolecularintramolecular
Vibrational Predissociation
4003002001000
delay time Δ t (ps)
a)
b)
c )
d)
Time Profile
phenol-dphenol-d11▪▪(D(D22O)O)
ODIRODD
intramolecularVR τ1 = 12 ps intermolecularVR τ2 = 24 ps
VP τ3 = 100 ps
Energy diagramH-bonded νOD = 2600 cm-1
S 0
H - bondedO D
S 1
IP
IR
U V
U V
intramolec ularV R
intermolec ularV R
phenol- d1- (D 2O )
phenol- d1 + D 2O
dissoc iation
vibrationalpredissoc iation
U V U V
U V U V
Δ t
τ 1
2560 2600 2640
IR wavenumber (c m- 1)
vO D
τ 2 τ 3
U V energy
0
O D intermolecularintramolecular
Vibrational Predissociation
Time Profile
phenol-dphenol-d00▪▪(H(H22O)O)
ODIRODD
U V energy
0
O H intermolecularintramolecular
Vibrational Predissociation
* Doi, A.; Mikami, N. J. Chem. Phys. Vol. 129, pp. 154308. (2008)
intramolecularVR τ1 = 4 ps * intermolecularVR τ2 = 5 ps
VP τ3 = 25 ps
Energy diagram
S 0
H- bondedO H
S 1
IP
IR
U V
U V
intramolec ularV R
intermolec ularV R
phenol- d0- (H 2O )
phenol- d0 + H 2O
dissoc iation
vibrationalpredissoc iation
U V U V
U V U V
Δ t
3480 3520 3560
vOH
IR wavenumber (cm-1)
τ 1 τ 2 τ 3
H-bonded νOH = 3525 cm-1
4003002001000
b)
c )
d)
delaytimeΔ t (ps)
phenol-water complexphenol-water complex
RRKM theory
)(
)(1)( 0
. E
EEW
hEk D
diss
excess energy~600cm-1
excess energy~1525cm-1
HH
DD
3525cm-1
2600cm-1
HH
DD
E0
EDdiss.energy~2000cm-1
Energy scheme
phenol-d1(D2O):
pskRRKM
RRKM 6.431
phenol-d0(H2O):
RRKM
RRKM k
1
1525
Summary 3Summary 3
*Petkovic, M. Journal of Physical Chemistry A, Vol. 116, pp. 364-371 (2012)
dominantIntermolecular vibrationalmode for dissociation*
S 0
O D
IR
S 1
intramolecularvibration
intermolecularvibration
Δ v =0,± 1,± 2,.. Δ v =0
vibrationalpredissociation
Future WorksFuture Works Obtain more data about IVR process of phenol-
derivatives after the OH stretching vibration
Measure the predissociation lifetime of various H-bonded phenol-d1▪(X) complexes
where X = (π-type) acetylene, ethylene, benzene,
(σ-type) dimethyl ether, etc
Effect of intramolecular hydrogen-bonding?Coupling of non-CH related vibrational modes and its IVR rate?
Comparison to the dissociation lifetime of phenol-d0(X) complex