Sökning: "photodissociation"
Visar resultat 1 - 5 av 27 avhandlingar innehållade ordet photodissociation.
1. Atomic and Molecular Dynamics Probed by Intense Extreme Ultraviolet Attosecond Pulses
Sammanfattning : This thesis work was aimed to investigate dynamical processes in atoms and molecules on ultrafast time scales initiated by absorption of light in the extreme ultraviolet (XUV) regime. In particular, photoionization and photodissociation have been studied using pump-probe techniques involving ultrafast laser pulses. LÄS MER
2. Quantum and quantum-classical calculations of core-ionized molecules in varied environments
Sammanfattning : Computational quantum chemistry methods have been applied in two particular cases: to provide insight to photoionization induced fragmentation of HgBr2 and HgCl2 molecules, and to study core-electron binding energies and chemical shifts of molecules in liquid, surface adsorbed and polymeric environments in the framework of quantum mechanics/molecular mechanics (QM/MM). In the photodissociation studies the computational work is based on the relativistic Dirac equation as the systems present strong spin-orbit interaction affecting the fragmentation processes. LÄS MER
3. Investigation of Ultrafast Molecular Dynamics via Covariance Mapping : A Tool for Intense XUV Light Sources
Sammanfattning : The study of molecular dynamics involves observations of the motion of nuclei and electrons. While nuclear motion is usually on the picosecond or femtosecond timescale, attosecond precision is necessary to directly observe the motion of electrons. LÄS MER
4. X-ray Absorption and Fragmentationas Initial Steps of Radiation Damage in Free Organic Molecules and Nanoparticles
Sammanfattning : Understanding the molecular radiation damage is crucial in radiobiology, molecular physics, and atmospheric science. In this thesis, the initial steps of radiation damage of anhydrous gas-phase molecules and hydrated nanoparticles were studied using synchrotron radiation based electron-ion coincidence spectroscopy and X-ray absorption spectroscopy under vacuum conditions. LÄS MER
5. Ultrafast Photo-induced Reaction Dynamics of Small Molecules
Sammanfattning : The main focus of this thesis is the investigation of the dissociation dynamics of aryl halides using femtosecond pump-probe spectroscopy. In the monohalogenated aryl halides, iodo-, bromo- and chlorobenzene, the rate of dissociation following excitation at 266 nm in the gas phase increased with increasing mass of the halogen atom. LÄS MER