Femtosecond dynamics and near-field microscopy of chemical and biological objects A.N. Petrukhin, O.M. Sarkisov Institute of Chemical Physics Moscow, Russia

1.Femtosecond dynamics of bifunctional molecules. 2.Near-field microscopy of lipofuscin granules from human eyes.

Photochromic reactionESIPT reaction C-O bond cleavage: fs Formation of intermediate X: fs Formation of colored photoproduct ( nm): ps Excited state intramolecular proton transfer (ESIPT): < 80 fs Formation of twisted structure: 0.3 – 4.4 ps Formation of colored photoproduct ( nm): 3.8 – 14 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. F.E. Gostev, A.N. Petrukhin, A.A. Titov, V.A. Nadtochenko, A.V. Metelitsa, V.I. Minkin, O.M. Sarkisov, Rus. Chem. Bul , h

Bifunctional molecules: compounds 1-3 1: 2: 3: Does proton transfer take place?

Pump: 405 nm, 40 fs Probe: Supercontinuum, nm Experimental setup

Photoinduced absorption dynamics

Product yield ratio dependence on pump energy Compounds 1,2 S0S0 S 1 ** S 1 K* S1KS1K S0KS0K S1*S1* XB B S0KS0K S0KS0K B 120 fs 800 fs 20 ps 400 fs 3 ps B – photochromic product S 0 K – ESIPT product ESIPT C-O cleavage

Product yield ratio dependence on pump energy Compound 3 S0S0 S 1 ** S 1 K* S1KS1K S0KS0K S2*S2* XB 850 fs3 ps 450 fs 21 ps B S0KS0K S0KS0K B 120 fs B – photochromic product S 0 K – ESIPT product C-O cleavage ESIPT

Compound 1. Kinetic curve at 510 nm Pump pulse chirp influence on wave packet motion

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.

200 nm Single LF granule. Atomic-force microscopy. Topography 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?

Prof. Oleg Sarkisov Prof. Victor Nadtochenko Andrey Titov Fyodor Gostev Andrey Petrukhin Andrey Frolov Alexander Sobennikov Arseniy Aybushev Artem Astafyev Ivan Shelaev Pavel Zolotavin Institute of Chemical Physics Moscow, Russia Thank you very much! Laser spectroscopy Lab femto.chph.ras.ru Our team: