Contents
xi
5.2.2 Photoelectron Angular Distributions: Using the Free
Electron to Map Excited State Dynamics . . . . . . . . . 103
5.3 The Experimental Toolkit for TRPES . . . . . . . . . . . . . . . 104
5.3.1 Femtosecond Light Sources . . . . . . . . . . . . . . . . 104
5.3.2 Molecular Sources . . . . . . . . . . . . . . . . . . . . . 106
5.3.3 Photoelectron Spectrometers . . . . . . . . . . . . . . . 107
5.4 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
5.4.1 Internal Conversion and Intramolecular Vibrational
Energy Redistribution . . . . . . . . . . . . . . . . . . . 108
5.4.2 Molecular Alignment . . . . . . . . . . . . . . . . . . . 109
5.4.3 Photodissociation . . . . . . . . . . . . . . . . . . . . . 111
5.4.4 Solvated Electrons . . . . . . . . . . . . . . . . . . . . . 113
5.4.5 VUV TRPES . . . . . . . . . . . . . . . . . . . . . . . . 113
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
6
Biomolecules, Photostability and 1 πσ ∗ States: Linking These
with Femtochemistry . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Gareth M. Roberts and Vasilios G. Stavros
6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
6.2 Excited Electronic States and Photostability . . . . . . . . . . . 120
6.2.1 H-Atom Elimination Dynamics Mediated by 1 πσ ∗
States . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
6.2.2 Non-adiabatic, Adiabatic and Tunneling dynamics . . . . 122
6.3 Experimental Detection of 1 πσ ∗ Mediated Dynamics . . . . . . 123
6.3.1 Time-Resolved Time-of-Flight Mass Spectrometry . . . . 124
6.3.2 Time-Resolved Velocity Map Ion Imaging . . . . . . . . 125
6.4 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
6.4.1 Non-adiabatic Versus Adiabatic Dynamics . . . . . . . . 128
6.4.2 Comparing Dynamics in Simple Azoles . . . . . . . . . . 130
6.4.3 Excited State H-Atom Tunneling Dynamics . . . . . . . 133
6.4.4 Competing 1 πσ ∗ Mediated Dissociation Pathways . . . . 136
6.4.5 Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . 139
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
7
Ultrafast Laser-Induced Processes Described by Ab Initio
Molecular Dynamics . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Leticia González, Philipp Marquetand, Martin Richter, Jesús
González-Vázquez, and Ignacio Sola
7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
7.2 Methodologies for Ab Initio Molecular Dynamics . . . . . . . . 148
7.2.1 Surface Hopping vs. Ehrenfest Dynamics . . . . . . . . . 148
7.2.2 Laser-Induced Dynamics: FISH vs. SHARC . . . . . . . 151
7.3 Examples of Laser-Free Dynamics . . . . . . . . . . . . . . . . 157
7.4 Examples of Laser-Induced Dynamics . . . . . . . . . . . . . . 159
7.4.1 Impulsive Regime . . . . . . . . . . . . . . . . . . . . . 159
xi
5.2.2 Photoelectron Angular Distributions: Using the Free
Electron to Map Excited State Dynamics . . . . . . . . . 103
5.3 The Experimental Toolkit for TRPES . . . . . . . . . . . . . . . 104
5.3.1 Femtosecond Light Sources . . . . . . . . . . . . . . . . 104
5.3.2 Molecular Sources . . . . . . . . . . . . . . . . . . . . . 106
5.3.3 Photoelectron Spectrometers . . . . . . . . . . . . . . . 107
5.4 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
5.4.1 Internal Conversion and Intramolecular Vibrational
Energy Redistribution . . . . . . . . . . . . . . . . . . . 108
5.4.2 Molecular Alignment . . . . . . . . . . . . . . . . . . . 109
5.4.3 Photodissociation . . . . . . . . . . . . . . . . . . . . . 111
5.4.4 Solvated Electrons . . . . . . . . . . . . . . . . . . . . . 113
5.4.5 VUV TRPES . . . . . . . . . . . . . . . . . . . . . . . . 113
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
6
Biomolecules, Photostability and 1 πσ ∗ States: Linking These
with Femtochemistry . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Gareth M. Roberts and Vasilios G. Stavros
6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
6.2 Excited Electronic States and Photostability . . . . . . . . . . . 120
6.2.1 H-Atom Elimination Dynamics Mediated by 1 πσ ∗
States . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
6.2.2 Non-adiabatic, Adiabatic and Tunneling dynamics . . . . 122
6.3 Experimental Detection of 1 πσ ∗ Mediated Dynamics . . . . . . 123
6.3.1 Time-Resolved Time-of-Flight Mass Spectrometry . . . . 124
6.3.2 Time-Resolved Velocity Map Ion Imaging . . . . . . . . 125
6.4 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
6.4.1 Non-adiabatic Versus Adiabatic Dynamics . . . . . . . . 128
6.4.2 Comparing Dynamics in Simple Azoles . . . . . . . . . . 130
6.4.3 Excited State H-Atom Tunneling Dynamics . . . . . . . 133
6.4.4 Competing 1 πσ ∗ Mediated Dissociation Pathways . . . . 136
6.4.5 Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . 139
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
7
Ultrafast Laser-Induced Processes Described by Ab Initio
Molecular Dynamics . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Leticia González, Philipp Marquetand, Martin Richter, Jesús
González-Vázquez, and Ignacio Sola
7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
7.2 Methodologies for Ab Initio Molecular Dynamics . . . . . . . . 148
7.2.1 Surface Hopping vs. Ehrenfest Dynamics . . . . . . . . . 148
7.2.2 Laser-Induced Dynamics: FISH vs. SHARC . . . . . . . 151
7.3 Examples of Laser-Free Dynamics . . . . . . . . . . . . . . . . 157
7.4 Examples of Laser-Induced Dynamics . . . . . . . . . . . . . . 159
7.4.1 Impulsive Regime . . . . . . . . . . . . . . . . . . . . . 159