Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 27 for “"Vibrational Dynamics"”.
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An investigation into vibrational dynamics in organic semiconductors
This thesis is concerned with study of vibrational dynamics and their effect on charge transport in thin films of organic semiconductors. Two classes of organic semiconductors are investigated- crystalline small molecules and conjugated polymers. Although device performance of both classes of …
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Vibrational dynamics in water from the molecule's perspective
… larger scale molecular reorganization destroys vibrational coherence.
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Ultrafast Vibrational Dynamics of Water and Confined Water in Reverse Micelles
A fast vibrational energy transfer across the surfactant layer of AOT reverse micelles has been measured in small AOT reverse micelles (AOT/water/CCl 4). Most of the vibrational energy from nanodroplet water is transferred to the AOT head group and then out to the CCl4 within 10 picoseconds. The …
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Vibrational dynamics of aqueous hydroxide solutions studied using ultrafast infrared spectroscopy
… to the strength of hydrogen bonding and hence vibrational frequencies, intensities and line shapes are closely associated with the structure and dynamics of the hydroxide ions. In this thesis, we have employed ultrafast infrared spectroscopy in conjunction with theoretical modeling to …
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Studying Ultrafast Vibrational dynamics of Intramolecular Hydrogen Bonds using Broadband Infrared Pump-Probe Spectroscopy.
… electron transfer across long distances. The vibrational dynamics of intramolecular hydrogen bonds pose experimental and theoretical challenges due to anharmonic couplings between the high frequency hydrogen bond stretching (νOH) mode and low frequency skeletal motions. This dissertation …
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Vibrational dynamics in strong glasses: the cases of densified v-SiO2 and v-SiSe2
In this work we will face the problem of the vibrational properties of glasses focusing on the origin and nature of the boson peak (BP). This feature is an universal characteristic of glasses and a fingerprint of the presence of disorder. Two samples have been chosen for this study. The first is …
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Vibrational Dynamics in Disordered Molecular Crystals by Picosecond Coherent Raman and Photon Echo Spectroscopies (Exciton, Low Temperature)
An understanding of vibrational dynamics in complex molecules is a fundamental problem in chemical physics and is important for discerning how vibrational relaxation effects actual chemical reaction rates. The natural states of a pure crystal, however, are delocalized excitons and are described by …
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Terahertz spectroscopy to explore the role of vibrational dynamics in systems with varying structural order and disorder
… obscured the boson peak, and influenced the vibrational density of states. The effect of the relative water content in aqueous mixtures of glycerol at room temperature was also explored. By utilising four different model biopharmaceuticals, the effect of size on the dynamics of one-component …
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The distribution of local enhancement factors in surface enhanced Raman-active substrates and the vibrational dynamics in the liquid phase
… of 790nm laser. On the second project, vibrational dynamics in the liquid phase has been investigated thoroughly with ultrafast time-resolved anti-Stokes Raman spectroscopy. With the only method up-to-date that provides real-time state-resolved measurements of vibrational energy flow in …
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Spin lattice relaxation studies on iron proteins
The fractal model relating protein structure and vibrational dynamics is reviewed and refined. The temperature dependence of electron spin-lattice relaxation stimulated by Raman phonon scattering is measured in low spin ferric proteins. The data are analysed to yield the spectral dimension, a …
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Vibrational Relaxation and Delocalization in Molecular Crystals and Biological Systems
Perturbations to the vibrational Hamiltonian of isolated gas molecules resulting from a crystalline environment are examined. FTIR is used to study the effects of two different crystal fields on the vibrational modes of perylene and Picosecond Coherent Raman Scattering (ps CARS) is applied to the …
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Time-Resolved Interactions of Infrared Vibrations and Plasmonic Nanogaps
The precise control of vibrational energy transfer at the molecular scale is crucial within the development of new platforms for quantum optics, optoelectronics, energy harvesting, and nanochemical reactions. Whilst the plasmonic enhancement offered by metal nanostructures can dramatically enhance …
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Dynamically motivated spectroscopy of small polyatomic molecules
Molecular vibrational dynamics far from equilibrium, or in the vicinity of saddle points, are of utmost importance in chemistry. However, most of the standard models used by chemists only perform well near local minima in the potential energy surface. Several spectroscopic techniques are developed …
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Nonlinear Dynamics Analysis and Control of Space Vehicles with Flexible Structures
… must consider the nonlinear rotational and vibrational dynamics of these flexible structures. Formulation and analysis of these flexible structures must account for the rigid-flexible coupling present in the system dynamics for stability analysis and control design. The system model is …
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Dynamical perspective of stability in glasses
… how glass stability influences microscopic dynamics over a wide range of timescales, from picosecond vibrations to structural relaxations lasting hundreds of seconds. Different stability regimes are explored by combining distinct preparation methods, such as physical vapor deposition, with …
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Spectroscopic investigations of hydrogen bond dynamics in liquid water
… influence hydrogen bonds have on its microscopic dynamics. However, because of the fast timescales involved, there are relatively few experimental techniques capable of directly probing rearrangements of water's hydrogen bonded network. In this thesis, I investigate ultrafast intermolecular …
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Vibrational Spectroscopy and Potential Energy Surface Analysis of the X˜ And B˜ States of Thiophosgene
… originating from eight B˜(1A1) state vibrational levels, have been measured by dispersed fluorescence spectroscopy. More than 370 of these vibrational fundamentals, overtones, and combination bands were assigned and fit with a simple spectroscopic Hamiltonian. Observed transitions are …
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Spectroscopic investigations of the X and A state dynamics of ¹³C₂H₂
… to perform a detailed spectroscopic study of the dynamics on the A and X state surfaces of 13C2H2 in order to further understand the acetylene - vinylidene isomerization process in the ground electronic state. Acetylene exemplifies one of the simplest bond-breaking isomerization systems and it has …
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Molecular Structure, Diffusion Dynamics and Hydration Energetics of Non-Confined Water and Water at Mineral Surfaces
Molecular dynamics (MD) computational modeling studies of the structure, dynamics and energetics of water at surfaces and in nano-confined spaces provide greatly increased, atomistically detailed understanding of the effects of surface structure and composition on the structural ordering, hydrogen …
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Ultrafast Raman Scattering in Plasmonic Nanocavities
… beyond, but investigating their coherence and dynamics is difficult as pulsed experiments prove very challenging. In this thesis, I study vibrations of 1-1000 molecules in a plasmonic nanocavity when driven by picosecond pulsed lasers out of the linear regime. This unravels new non-linear …
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