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:

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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 Laser Spectroscopy
Femtosecond Laser Spectroscopy

Author: Peter Hannaford

Publisher: Springer Science & Business Media

Published: 2005-12-27

Total Pages: 350

ISBN-13: 038723294X

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The embryonic development of femtoscience stems from advances made in the generation of ultrashort laser pulses. Beginning with mode-locking of glass lasers in the 1960s, the development of dye lasers brought the pulse width down from picoseconds to femtoseconds. The breakthrough in solid state laser pulse generation provided the current reliable table-top laser systems capable of average power of about 1 watt, and peak power density of easily watts per square centimeter, with pulse widths in the range of four to eight femtoseconds. Pulses with peak power density reaching watts per square centimeter have been achieved in laboratory settings and, more recently, pulses of sub-femtosecond duration have been successfully generated. As concepts and methodologies have evolved over the past two decades, the realm of ultrafast science has become vast and exciting and has impacted many areas of chemistry, biology and physics, and other fields such as materials science, electrical engineering, and optical communication. In molecular science the explosive growth of this research is for fundamental reasons. In femtochemistry and femtobiology chemical bonds form and break on the femtosecond time scale, and on this scale of time we can freeze the transition states at configurations never before seen. Even for n- reactive physical changes one is observing the most elementary of molecular processes. On a time scale shorter than the vibrational and rotational periods the ensemble behaves coherently as a single-molecule trajectory.

The Chemical Bond
The Chemical Bond

Author: Ahmed Zewail

Publisher: Elsevier

Published: 1992-05-14

Total Pages: 333

ISBN-13: 008092669X

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This inspired book by some of the most influential scientists of our time--including six Nobel laureates--chronicles our emerging understanding of the chemical bond through the last nine decades and into the future. From Pauling's early structural work using x-ray and electron diffraction to Zewail's femtosecond lasers that probe molecular dynamics in real time; from Crick's molecular biology to Rich's molecular recognition, this book explores a rich tradition of scientific heritage and accomplishment. The perspectives given by Pauling, Perutz, Rich, Crick, Porter, Polanyi, Herschbach, Zewail, and Bernstein celebrate major scientific achievements in chemistry and biology with the chemical bond playing a fundamental role. In a unique presentation that also provides some lively insights into the very nature of scientific thought and discovery, The Chemical Bond: Structure and Dynamics will be of general interest to scientists, science historians, and the scientifically inclined populous.

Springer Handbook of Lasers and Optics
Springer Handbook of Lasers and Optics

Author: Frank Träger

Publisher: Springer Science & Business Media

Published: 2012-05-05

Total Pages: 1704

ISBN-13: 3642194095

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This new edition features numerous updates and additions. Especially 4 new chapters on Fiber Optics, Integrated Optics, Frequency Combs and Interferometry reflect the changes since the first edition. In addition, major complete updates for the chapters: Optical Materials and Their Properties, Optical Detectors, Nanooptics, and Optics far Beyond the Diffraction Limit. Features Contains over 1000 two-color illustrations. Includes over 120 comprehensive tables with properties of optical materials and light sources. Emphasizes physical concepts over extensive mathematical derivations. Chapters with summaries, detailed index Delivers a wealth of up-to-date references.

Advances in Multi-photon Processes and Spectroscopy
Advances in Multi-photon Processes and Spectroscopy

Author: Y. Fujimura

Publisher: World Scientific

Published: 2001

Total Pages: 356

ISBN-13: 9789812791948

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In view of the rapid growth in both experimental and theoretical studies of multi-photon processes and multi-photon spectroscopy of atoms, ions and molecules in chemistry, physics, biology, materials science, etc., it is desirable to publish an advanced series of volumes containing review papers that can be read not only by active researchers in these areas, but also by those who are not experts but who intend to enter the field. The present series aims to serve this purpose. Each review article is written in a self-contained manner by the expert(s) in the area, so that the reader can grasp the knowledge without too much preparation.

Molecular Dynamics and Spectroscopy by Stimulated Emission Pumping
Molecular Dynamics and Spectroscopy by Stimulated Emission Pumping

Author: Hai-Lung Dai

Publisher: World Scientific

Published: 1995

Total Pages: 1154

ISBN-13: 9789810217495

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Since the first stimulated emission pumping (SEP) experiments more than a decade ago, this technique has proven powerful for studying vibrationally excited molecules. SEP is now widely used by increasing numbers of research groups to investigate fundamental problems in spectroscopy, intramolecular dynamics, intermolecular interactions, and even reactions. SEP provides rotationally pre-selected spectra of vibrationally highly excited molecules undergoing large amplitude motions. A unique feature of SEP is the ability to access systematically a wide variety of extreme excitations localized in various parts of a molecule, and to prepare populations in specific, high vibrational levels. SEP has made it possible to ask and answer specific questions about intramolecular vibrational redistribution and the role of vibrational excitation in chemical reactions.

Spectroscopy and Modeling of Biomolecular Building Blocks
Spectroscopy and Modeling of Biomolecular Building Blocks

Author: Jean-Pierre Schermann

Publisher: Elsevier

Published: 2007-10-16

Total Pages: 499

ISBN-13: 0080558224

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Spectroscopy and Modeling of Biomolecular Building Blocks presents an overview of recent advances in the intertwining of the following research fields: photon and electron spectroscopy, quantum chemistry, modelling and mass-spectrometry. The coupling of these disciplines offers a new point of view to the understanding of isolated elementary building blocks of biomolecules and their assemblies. It allows the unambiguous separation between intrinsic properties of biomolecular systems and those induced by the presence of their environment. The first chapters provide background in modelling (I), frequency-resolved spectroscopy using microwave, infrared and UV photons, time-resolved spectroscopy in the femtosecond domain and energy-resolved electron spectroscopy (II) and production of gas-phase neutral and ionic biomolecular species, mass-spectrometry, ion mobility and BIRD techniques (III). Chapter IV is devoted to case studies of gas-phase experimental investigations coupled to quantum or classical calculations. The topics are structural studies of nucleobases and oligonucleotides, peptides and proteins, sugars; neuromolecules; non-covalent complexes; chiral systems, interactions of low-energy electrons with biomolecules in the radiation chemistry context and very large gas-phase biomolecular systems. The fifth chapter concerns the link between gas-phase and liquid-phase. Different treatments of solvation are illustrated through examples pointing out the influence of progressive addition of water molecules upon properties of nucleobases, peptides, sugars and neuromolecules. - Offer a new perspective to the understanding of isolated elementary building blocks of bio molecules - Includes case studies of experimental investigations coupled to quantum or classical calculations

Advances In Multi-photon Processes And Spectroscopy, Vol 14 - Proceedings Of The Us–japan Workshop
Advances In Multi-photon Processes And Spectroscopy, Vol 14 - Proceedings Of The Us–japan Workshop

Author: Yuichi Fujimura

Publisher: World Scientific

Published: 2000-12-13

Total Pages: 349

ISBN-13: 981449173X

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In view of the rapid growth in both experimental and theoretical studies of multi-photon processes and multi-photon spectroscopy of atoms, ions and molecules in chemistry, physics, biology, materials science, etc., it is desirable to publish an advanced series of volumes containing review papers that can be read not only by active researchers in these areas, but also by those who are not experts but who intend to enter the field. The present series aims to serve this purpose. Each review article is written in a self-contained manner by the expert(s) in the area, so that the reader can grasp the knowledge without too much preparation.

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

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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.