Investigation of Complex Molecular Dynamics in the Gas Phase Using Femtosecond Four-wave Mixing Spectroscopy
Investigation of Complex Molecular Dynamics in the Gas Phase Using Femtosecond Four-wave Mixing Spectroscopy

Author: Abraham Vamattathil Scaria

Publisher:

Published: 2008

Total Pages: 112

ISBN-13:

DOWNLOAD EBOOK

Ultrafast spectroscopy is one of the most active areas of research in chemical physics. Understanding the ultrafast behavior of molecules, and influencing it with the help of laser fields may lead to the ultimate goal of controlling the flow and outcome of chemical reactions. This thesis work focuses on the investigation and control of molecular dynamics using time-resolved four-wave mixing (FWM) techniques in gas phase samples. Femtosecond FWM spectroscopy has established itself as a powerful tool to uncover molecular dynamics on ultrafast time scales. The femtosecond time resolution combined with a background-free, highly collimated coherent signal makes the approach unique for studying the dynamics especially under conditions of low concentrations. In gas phase, the elementary reaction paths can be directly probed without the interference of solvent molecules. A comparative study of the molecular dynamics in the gas phase and condensed phase gives a detailed picture on the effect of environment. Utilization of Raman as well as optical resonances in FWM spectroscopy provided high selectivity with respect to the type of molecular dynamics observed in the transient signal. New schemes of FWM spectroscopy, which employs an initial pump pulse along with a fully time resolved FWM process, were devised to monitor also the dynamics of higher lying excited states. A feed back controlled optimization process in a FWM scheme is used to selectively excite or suppress vibrational modes in gas phase and liquid phase of the same molecule. The results of the experiments performed using different FWM techniques to monitor, understand, and also to control diverse aspects of molecular dynamics in different systems are presented and discussed.

Femtosecond Reaction Dynamics
Femtosecond Reaction Dynamics

Author: Douwe A. Wiersma

Publisher: North Holland

Published: 1994

Total Pages: 324

ISBN-13:

DOWNLOAD EBOOK

Presents the state-of-the-art, both from a theoretical and experimental point of view, in the field of femtochemistry. The book contains in-depth coverage of femtosecond gasphase reaction dynamics, coherent and coherence effects in solution, and coherent control of chemical reactions.

Ultrafast Phenomena in Molecular Sciences
Ultrafast Phenomena in Molecular Sciences

Author: Rebeca de Nalda

Publisher: Springer Science & Business Media

Published: 2013-10-22

Total Pages: 298

ISBN-13: 331902051X

DOWNLOAD EBOOK

This book presents the latest developments in Femtosecond Chemistry and Physics for the study of ultrafast photo-induced molecular processes. Molecular systems, from the simplest H2 molecule to polymers or biological macromolecules, constitute central objects of interest for Physics, Chemistry and Biology, and despite the broad range of phenomena that they exhibit, they share some common behaviors. One of the most significant of those is that many of the processes involving chemical transformation (nuclear reorganization, bond breaking, bond making) take place in an extraordinarily short time, in or around the femtosecond temporal scale (1 fs = 10-15 s). A number of experimental approaches - very particularly the developments in the generation and manipulation of ultrashort laser pulses - coupled with theoretical progress, provide the ultrafast scientist with powerful tools to understand matter and its interaction with light, at this spatial and temporal scale. This book is an attempt to reunite some of the state-of-the-art research that is being carried out in the field of ultrafast molecular science, from theoretical developments, through new phenomena induced by intense laser fields, to the latest techniques applied to the study of molecular dynamics.

Transient Changes in Molecular Geometries and How to Model Them
Transient Changes in Molecular Geometries and How to Model Them

Author: Asmus Ougaard Dohn

Publisher: Springer

Published: 2015-06-06

Total Pages: 174

ISBN-13: 3319187473

DOWNLOAD EBOOK

This thesis examines various aspects of excess excitation energy dissipation via dynamic changes in molecular structure, vibrational modes and solvation. The computational work is carefully described and the results are compared to experimental data obtained using femtosecond spectroscopy and x-ray scattering. The level of agreement between theory and experiment is impressive and provides both a convincing validation of the method and significant new insights into the chemical dynamics and molecular determinants of the experimental data. Hence, the method presented in the thesis has the potential to become a very important contribution to the rapidly growing field of femtosecond x-ray science, a trend reflected in the several free-electron x-ray lasers (XFELs) currently being built around the world. Light-induced chemical processes are accompanied by molecular motion of electrons and nuclei on the femtosecond time scale. Uncovering these dynamics is central to our understanding of the chemical reaction on a fundamental level. Asmus O. Dohn has implemented a highly efficient QM/MM Direct Dynamics method for predicting the solvation dynamics of transition metal complexes in solution.

Femtochemistry and Femtobiology
Femtochemistry and Femtobiology

Author: Abderrazzak Douhal

Publisher: World Scientific

Published: 2002

Total Pages: 854

ISBN-13: 9810248660

DOWNLOAD EBOOK

This book contains important contributions from top international scientists on the-state-of-the-art of femtochemistry and femtobiology at the beginning of the new millennium. It consists of reviews and papers on ultrafast dynamics in molecular science.The coverage of topics highlights several important features of molecular science from the viewpoint of structure (space domain) and dynamics (time domain). First of all, the book presents the latest developments, such as experimental techniques for understanding ultrafast processes in gas, condensed and complex systems, including biological molecules, surfaces and nanostructures. At the same time it stresses the different ways to control the rates and pathways of reactive events in chemistry and biology. Particular emphasis is given to biological processes as an area where femtodynamics is becoming very useful for resolving the structural dynamics from techniques such as electron diffraction, and X-ray and IR spectroscopy. Finally, the latest developments in quantum control (in both theory and experiment) and the experimental pulse-shaping techniques are described.

Femtochemistry and Femtobiology
Femtochemistry and Femtobiology

Author: Monique M. Martin

Publisher: Elsevier

Published: 2004-04-16

Total Pages: 589

ISBN-13: 0080506267

DOWNLOAD EBOOK

This book reflects the heights of knowledge of ultrafast chemical processes attained in these early years of the 21st century : the latest research in femtosecond and picosecond molecular processes in Chemistry and Biology, carried out around the world, is described here in more than 110 articles. The results were presented and discussed at the VIth International Conference on Femtochemistry, in Paris, France, from July 6 to July 10, 2003. The articles published here were reviewed by referees selected from specialists in the Femtochemistry community, guaranteeing a collective responsability for the quality of the research reported in the next 564 pages. Femtochemistry is an ever-growing field, where new research areas are constantly opening up, and one which both stimulates and accompanies the development of ultrafast technologies. The increasing interest in femtobiology and chemistry at the frontier with biology is an obvious indicator of the present impact of life sciences in our society. New materials and reactions at surfaces are also some of the relatively new topics that promise rapid developments. New methodologies and technologies for probing and following in real time molecular dynamical phenomena have appeared within the last ten years or so. These methods, based on multidimensional IR spectroscopies, ultrafast X-ray and electron diffraction techniques, are well represented in this book. Of ever-improving performance, they are now applied to the characterization of structural dynamics of an increasing number of chemical and biological systems.This book reports the state of research in Femtochemistry and Femtobiology presented at Paris, at the Maison de la Chimie, in July 2003, representing the tenth anniversary of the conference.* Overview of the most recent research on ultrafast events* Application of new methodologies on chemical and biological systems* Contributions by key players in the field