Transcript Document

Institute of Chemical Physics
Moscow, Russia
Femtosecond dynamics
and near-field microscopy
of chemical and biological objects
A.N. Petrukhin, O.M. Sarkisov
1. Femtosecond dynamics of
bifunctional molecules.
2. Near-field microscopy of lipofuscin
granules from human eyes.
Photochromic reaction
O
C
H
H
3C
3 h
N
У
Ф
N
O
C
H
3
C-O bond cleavage:
ESIPT reaction
H
N
C
H
CH
3C
3
H N
N
C
H
3
250 - 400 fs
h
O
C
H
 = 900
H
N+
O
Excited state intramolecular proton
transfer (ESIPT):
< 80 fs
Formation of intermediate X:
Formation of twisted structure:
Formation of colored
photoproduct (550-600 nm):
Formation of colored photoproduct
(480-500 nm):
300-450 fs
1 - 3 ps
S.A. Antipin, A.N. Petrukhin, F.E. Gostev,
V.S. Marevtsev,A.A. Titov, V.A. Barachevsky,
Yu.P. Strokach, O.M. Sarkisov,
Chem. Phys. Lett. 331 (2000) 378.
0.3 – 4.4 ps
3.8 – 14 ps
F.E. Gostev, A.N. Petrukhin, A.A. Titov, V.A.
Nadtochenko, A.V. Metelitsa, V.I. Minkin, O.M. Sarkisov,
Rus. Chem. Bul. 2004. 23 , 11 3-14.
Bifunctional molecules: compounds 1-3
1:
CH3 CH3
N
H O
N
N O
CH3
C
H
2:
CH3 CH3
H O
N
N
N
C
H
O
CH3
NO2
3:
CH3 CH3
H O
N
N
CH3
Does proton transfer take place?
N
C
O
H
Br
Experimental
setup
Pump:
405 nm, 40 fs
Probe:
Supercontinuum,
410-800 nm
Photoinduced absorption dynamics
Photoinduced absorption dynamics
Product yield ratio dependence on pump energy
Compounds 1,2
800 fs
ESIPT
B
S1**
S0K
S0K
B
S0
S1K*
3 ps
S1 K
120 fs
S1*
400 fs
S0 K
20 ps
X
B
C-O
cleavage
B – photochromic product
S0K – ESIPT product
Product yield ratio dependence on pump energy
Compound 3
21 ps
450 fs
S2*
B
X
C-O
cleavage
120 fs
S0K
850 fs
S1K*
S1**
B
3 ps
S1 K
S0 K
ESIPT
S0
S0K
B – photochromic product
S0K– ESIPT product
B
Pump pulse chirp influence on wave packet motion
Compound 1. Kinetic curve at 510 nm
Pump pulse chirp influence on product yield ratio
Time delay = 200 ps
2. Near-field microscopy of lipofuscin
granules from human eyes.
Near-field microscopy. Experimental Setup.
Single LF granule. Atomic-force microscopy.
Topography
200 nm
Phase contrast
Single LF granule. Near-filed microscopy.
Topography
Transmission at 410 nm
Single LF granule. Near-filed microscopy.
Topography
Fluorescence spectra
Two photon microscopy of LP granules
Fluorescence decay of LH granules
under 400 nm fs irradiation
Fluorescence decay – epoxide formation?
Institute of Chemical Physics
Moscow, Russia
Our team:
Prof. Oleg Sarkisov
Prof. Victor Nadtochenko
Andrey Titov
Thank you very much!
Fyodor Gostev
Andrey Petrukhin
Andrey Frolov
Alexander Sobennikov
Arseniy Aybushev
Artem Astafyev
Ivan Shelaev
Pavel Zolotavin
Laser spectroscopy Lab
femto.chph.ras.ru
+7-095-939-7162