PC VIII: Femtochemistry and/or Photochemistry Organization Physikalische Chemie VIII: Spektroskopie II • Some exercises with Mathematica • Exercises 2 weeks • Debriefing: Thursday 8.00-10.00 in room 34-K-01 or 13K24 (through 13 K 26), every second week, start Oct. 4 • Return exercises Wednesday before 12.00 • Computer-Exam • Script (password PCseven7) Tutor: Fivos Perakis 34 K 30 Femtochemistry: Basic Concepts Examples of Photochemical Reactions Experimental Methods Motion in Quantum Mechanics: Wavepackets Franck-Condon Transition Jablonski Diagram, Fermi Golden Rule, Energy Gap Law Prototype Potential Energy Surfaces Non-Crossing Rule, Avoided Crossings, Conical Intersections Born Oppenheimer Approximation and its Breakdown Adiabatic and Diabatic Surfaces Mixed Quantum-Classical Methods, Landau Zener Theory Solvation Electron Transfer Theory Excitation Transfer: Exciton- and Förster Transfer S2 conical intersections solution phase dynamics fast (Kasha‘s Rule) kIVR 1-10 ps Period 2: slow Heavy elements: fast S1 kISC T 1 100ns kf kIC kp kISC 10ns 200fs –100ns (dipole allowed) S0 S1 Jablonski diagram Energy Free and energy gap rule electron transfer S Franck-Condon 0 transition D*A ED(R) + - D A Solvation Coordinate E (R) A solvation E FreeFree Energy Energy Ea E Adiabatic and diabatic surfaces, non- AB* AB* A*B R (D) R (A) R A*B crossing rule, Landau-Zener theory 0 0 LUMO LUMO HOMO Concepts HOMO excitation transfer motion in quantum mechanics Femtochemistry and Photochemistry Examples gas-phase chemistry vision natural and artifiicial photosynthesis coherent ind incoherent excitation transfer Femtochemistry Nobel Prize 1999 Ahmed Zewail The First Time-Resolved Photo Louis Jacques Mande Daguerre, 1839 Exposure Time: 10-20 min http://www.rleggat.com/photohistory/history/daguerr.htm Stroboskop Zeitauflösung: 1 ms ca. 1880 Zeitpfeil Radiowellen Mechanik Schall Computer 100 s10-3 s1010-6 s10-9 s 10-12 s -15 s 1 s 1 ms1 s 1 ns 1 ps 1 fs Proteindynamik Schwingungs- bewegung Diffusionskontrollierte Chemie Photochemie Energierelaxation 100 Femtosekunden Lichtgeschwindigkeit: 300.000 km/s 1 s: Erde → Mond 8 min: Erde → Sonne 100 fs: Dicke eines dünnen Blatt Papiers Short Pulses with Lasers 1E-3 1E-6 Q-Switching 1E-9 Mode Locking CPM Laser 1E-12 Compression Pulsewidth [sec] Pulsewidth 1E-15 ? 1960 1970 1980 1990 2000 Year Femtosecond Lasers CPM Laser 1980 Pump-Probe Spectroscopy Pump-Probe Spectroscopy Pump-Probe Spectroscopy Pump-Probe Spectroscopy Femtochemistry: Basic Concepts Examples of Photochemical Reactions Experimental Methods Motion in Quantum Mechanics: Wavepackets Franck-Condon Transition Jablonski Diagram, Fermi Golden Rule, Energy Gap Law Prototype Potential Energy Surfaces Non-Crossing Rule, Avoided Crossings, Conical Intersections Born Oppenheimer Approximation and its Breakdown Adiabatic and Diabatic Surfaces Mixed Quantum-Classical Methods, Landau Zener Theory Solvation Electron Transfer Theory Excitation Transfer: Exciton- and Förster Transfer Photochemical Reactions in Nature: Isomerization of Bacteriorhodopsin Wikipedia, Halobacteria in the salt lake Chokrak (Ukraine) Photochemical Reactions in Nature: Isomerization of Bacteriorhodopsin Photochemical Reactions in Nature: Isomerization of Bacteriorhodopsin http://www.biochem.mpg.de/oesterhelt/photobiology/br.html Photochemical Reactions in Nature: Isomerization of Bacteriorhodopsin Dobler, W. Zinth, W. Kaiser, D. Oesterhelt Excited-state reaction dynamics of Bacteriorhodopsin studied by femtosecond spectroscopy. Chem. Phys. Lett. 144 (Feb. 1988) 215 Photochemical Reactions in Nature: Isomerization of Bacteriorhodopsin Dobler, W. Zinth, W. Kaiser, D. Oesterhelt Excited-state reaction dynamics of Bacteriorhodopsin studied by femtosecond spectroscopy. Chem. Phys. Lett. 144 (Feb. 1988) 215 Vision: Isomerization in Rhodopsin movie Photochemical Reactions in Nature: Isomerization of Rhodopsin Q. Wang, R. W. Schoenlein, L. A. Peteanu, R. A. Mathies, C. V. Shank, Science 266 (1994) 422 Photochemical Reactions in Nature: Electron Transfer in Photosynthesis Photochemical Reactions in Nature: Photosynthesis in Green Plants Photochemical Reactions in Nature: Bacterial Photosynthesis Photochemical Reactions in Nature: Bacterial Photosynthesis Photochemical Reactions in Nature: Bacterial Photosynthesis Nobel Prize in Chemistry 1988 The structure of a photosynthetic reaction center, Johann Deisenhofer, Robert Huber and Hartmut Michel Photochemical Reactions in Nature: Electron Transfer in Photosynthesis W. Zinth, J. Wachtveitl ChemPhysChem 2005, 6, 871 – 880 Photochemical Reactions in Nature: Electron Transfer in Photosynthesis Photochemical Reactions in Nature: Myoglobin Friedrich Schotte, Manho Lim, Timothy A. Jackson, leksandr V. Smirnov, Jayashree Soman, John S. Olson, George N. Phillips Jr., Michael Wulff, Philip A. Anfinrud Watching a Protein as it Functions with 150-ps Time- Resolved X-ray Crystallography, Science, 300 1944 (2003) Prototype Photochemical Reactions in Chemistry Prototype Photochemical Reaction: ICN M. Dantus, M. J. Rosker, A. H. Zewail, J. Chem. Phys. 87 (1987) 2395 A. H. Zewail, J. Phys. Chem. A 104 (2000) 5660 + Photochemie: H2 -Molekül probe eV 4 3 2 probe 1 pump 1 2 3 4 R/Å -1 -2 Prototype Photochemical Reaction: NaI T. S. Rose, M. J. Rosker, A. H. Zewail, J. Chem. Phys. 91 (1989) 7415 A. H. Zewail, J. Phys. Chem. A 104 (2000) 5660 Motion in Quantum Mechanics: I2 M. Gruebele, A. H. Zewail, J. Chem. Phys. 98 (1993) 883 Ring Opening of 1-3-Cyclohexadien W. Fuß, W. E. Schmid, and S. A. Trushin, Time-resolved dissociative intense-laser field ionization for probing dynamics: Femtosecond photochemical ring opening of 1,3-cyclohexadiene, J. Chem. Phys. 112 (2000) 8347 Ring Opening of 1-3-Cyclohexadien H. Tamuraa S. Nanbu T. Ishida H. Nakamura Ab initio nonadiabatic quantum dynamics of cyclohexadiene/hexatriene ultrafast photoisomerization J Chem. Phys. 124, 084313 2006 Ring Opening of 1-3-Cyclohexadien H. Tamuraa S. Nanbu T. Ishida H. Nakamura Ab initio nonadiabatic quantum dynamics of cyclohexadiene/hexatriene ultrafast photoisomerization J Chem. Phys. 124, 084313 2006 Femtochemistry: Basic Concepts Examples of Photochemical Reactions Experimental Methods Motion in Quantum Mechanics: Wavepackets Franck-Condon Transition Jablonski Diagram, Fermi Golden Rule, Energy Gap Law Prototype Potential Energy Surfaces Non-Crossing Rule, Avoided Crossings, Conical Intersections Born Oppenheimer Approximation and its Breakdown Adiabatic and Diabatic Surfaces Mixed Quantum-Classical Methods, Landau Zener Theory Solvation Electron Transfer Theory Excitation Transfer: Exciton- and Förster Transfer Pump-Probe Spectroscopy The Laser Lab Ti:S Ti:S Oscillator Vis-OPA Amplifier IR-OPA Experiment Interaction of Light with Matter spontaneous stimulated Absorption Emission Emission h h h 4-Level System h optical pump Laser Laser Medium Output Coupler Short Pulses: - Broad Gain Medium (organic Dyes, Ti:S) - Mode Locking - Dispersion Control Laser Laser Medium Output Coupler l c/2l Gain Profile n-1 nn+1 Re(E(t)) -1 -0.5 0.5 1 t Re(E(t)) -6 -4 -2 2 4 6 t c i2n t 2l E(t) Ene n Random Phase E(t) 10 5 -6 -4 -2 2 4 6 -5 -10 c i2n t in 2l E(t) Ene e n Kerr Medium High Intensity Mode d0 Low Intensity z Mode Aperture Kerr Effect: n(I) n0 I n2 Dispersion ) ( n Visible Range c v ph n() c dn v gr n() c d Prism-Compressor A F L C E B D Ti:S Laser Ti:S Nd-YAG Laser Output Coupler - 10-100 fs - 750-900 nm - 100 MHz - 1 W (average) - 10 nJ/pulse Ti:S Laser Pump-Probe Spectroscopy The Laser Lab Ti:S Ti:S Oscillator Vis-OPA Amplifier IR-OPA Experiment Regenerative Amplifier in Pockels Cell Ti:S Nd-YAG Laser out - 10-100 fs - 760-850 nm Pockels - 1-10 kHz Cell - 1-10 W (average) - 1-10 mJ/pulse Chirped Pulse Amplification Ti:S Laser 100 fs 10 nJ/pulse 105 W 100 MHz Stretcher 100 ps 10 nJ/pulse 102 W 100 MHz Amplifier 100 ps 1 mJ/pulse 107 W 1 kHz Compressor 100 fs 1 mJ/pulse 1010 W 1 kHz Grating-Stretcher f 2ff leff<0 Grating-Compressor l Pump-Probe Spectroscopy The Laser Lab Ti:S Ti:S Oscillator Vis-OPA Amplifier IR-OPA Experiment Nonlinear Optics P 1 E 2 E E E E0 cost 1 P 1 E0 cos(t) 2 2 P 2 E0 1 cos(2t) Second Harmonic Generation Nonlinear Crystal =2 1 2 1 Nonlinear Optics P 1 E 2 E E E E0 cos1t E0 cos2t 2 2 P 2 E0 cos(1 2 )t cos(1 2 )t Sum Frequency Generation Nonlinear Crystal 2 3=1+2 1 Difference Frequency Mixing Nonlinear Crystal 3=2-1 1 Idler 2 1 Signal Optical Parametrical Process Nonlinear Crystal = - 3 2 1 Idler 2 1 Signal IR Light Source IR Pulses: R=1 m M2: Delay AgGaS • 100 fs I-II 2 -1 R=1m Typ I •200 cm 1.5 mm •1-2 J DM2 • 1000-3500 cm-1 200 µJ M1: Delay f=50 cm f=20 cm p-s 3.5 µJ R=50 cm f=-5 cm f=10 cm f=3 cm Ti:Sapphire:Ti:Sapphire: 800 nm, 90 fs 90 fs nm, nm, 800 800 2 µJ Sapphire DM1 BBO DM1 DM2 Typ II 4 mm P. Hamm et al. Opt. Lett. 25 (2000) 1798 White-light Generation Pump-Probe Spectroscopy Femtochemistry: Basic Concepts Examples of Photochemical Reactions Experimental Methods Motion in Quantum Mechanics: Wavepackets Franck-Condon Transition Jablonski Diagram, Fermi Golden Rule, Energy Gap Law Prototype Potential Energy Surfaces Non-Crossing Rule, Avoided Crossings, Conical Intersections Born Oppenheimer Approximation and its Breakdown Adiabatic and Diabatic Surfaces Mixed Quantum-Classical Methods, Landau Zener Theory Solvation Electron Transfer Theory Excitation Transfer: Exciton- and Förster Transfer Photochemical Reactions in Nature: Isomerization of Rhodopsin Q. Wang, R. W. Schoenlein, L. A. Peteanu, R. A. Mathies, C. V. Shank, Science 266 (1994) 422 Prototype Photochemical Reaction: NaI T. S. Rose, M. J. Rosker, A. H. Zewail, J. Chem. Phys. 91 (1989) 7415 A. H. Zewail, J. Phys. Chem. A 104 (2000) 5660 * Licht J. Phys. Chem.; 1991; 95; 2022. Inversion Tunneling in Ammonia (in He droplets) Chemicalresonance equilibrium structures x 1 1 cm-1 0 x J.