[PDF] Relaxation Processes In Molecular Excited States eBook

Author : J. Fünfschilling
Publisher : Springer Science & Business Media
Page : 282 pages
File Size : 49,36 MB
Release : 2012-12-06
Category : Science
ISBN : 9400908636

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Relaxation phenomena of excited molecular states are abundant in all nature. They mediate such key processes as photochemical reactions or even the pathways of ordinary chemical reactions. However, for a long time the main research in electronic relaxation processes was concerned with anorganic solids, in part because of their great technological importance (photography, semiconductors ... ) in part also because these compounds were the "workhorses" of the solid state physicists. In the last 30 years, there was a steadily increasing interest in organic molecular systems, first in molecular crystals and later in all forms of molecular solids (glasses, polymers, membranes, ... ). The present volume combines papers on quite different types of relaxation phenomena: the type of solid studied, the electronic states involved, the physical processes responsible for the relaxations are all different. Nevertheless, after reading this book, a more clear and complete picture of the phenomenon "relaxa tion" emerges that proves that this volume is more than just a collection of individual articles. The volume starts with the paper "Spin-lattice and spin-spin relaxation in photo-excited triplet states in molecular crystals" by Jan Schmidt. Even in these seemingly simple systems of isolated guest molecules in a single crystal host, the relaxation phenomena are quite involved and a very thorough investigation is necessary to find the key relaxation processes. The end of the article provides a bridge to the following paper: it treats interactions of two molecules (dimers), where resonant interactions become important and lead to new, characteristic relaxation processes.

Author : Edward Lim
Publisher : Elsevier
Page : 217 pages
File Size : 19,24 MB
Release : 2012-12-02
Category : Science
ISBN : 0323159982

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Excited States, Volume 5 consists of three concise and detailed chapters. These chapters cover the topics of excited-state potential surfaces of polyatomic molecules; vibronic spectroscopy of benzene; and quantum statistical mechanical (QSM) theory for molecular relaxation processes. Chapter 1 discusses excited-state potential surfaces with focus on ab initio calculations. Simple methods of computational schemes are also presented in this chapter. Chapter 2 reviews the excited electronic states of benzene. This chapter also includes the basic theory of benzene electronic excitations and the various types of spectroscopy (absorption, vibrational Raman, and electron-impact). Lastly, Chapter 3 presents a unified QSM theory, phenomenological theory of irreversible thermodynamics, and kinetics. The focus of QSM theory is on the nonlinear domain and is used to construct a nonlinear theory for the relaxation of excited molecules that are electric, vibrating, and rotating. This volume is a good reference for students and researchers studying in the field of chemistry and physics.

Author : Sheng Lin
Publisher : Elsevier
Page : 440 pages
File Size : 16,51 MB
Release : 2012-12-02
Category : Science
ISBN : 0323150276

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Radiationless Transitions is a critical discussion of research studies on the theory and experiments in radiationless transitions. This book is composed of nine chapters, and begins with discussions on the theory and experiment of photophysical processes of single vibronic levels and/or single rovibronic levels. The subsequent chapters deal with the spectroscopic investigations of intramolecular vibrational relaxation; the dynamics of molecular excitation by light; and the photophysical processes of small molecules in condensed phase. The discussions then shift to the high pressure effects on molecular luminescence and the internal conversion involving localized excitations, presenting one qualitative and one quantitative example, as well as the intersystem crossing with localized excitations. A chapter explores the energy transfer processes that occur after a molecule in solution is excited by light, with an emphasis on solid solutions in which the large amplitude molecular motion is largely quenched. This chapter also looks into the liquid solutions in which the molecules can translate and rotate under the influence of fluctuating forces from the liquid. The concluding chapter focuses on ultrafast processes. Researchers in the fields of physics, chemistry, and biology will benefit from this book.

Author : Detlef Bahnemann
Publisher : Springer Nature
Page : 1914 pages
File Size : 16,60 MB
Release : 2022-06-25
Category : Science
ISBN : 3030637131

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The handbook comprehensively covers the field of inorganic photochemistry from the fundamentals to the main applications. The first section of the book describes the historical development of inorganic photochemistry, along with the fundamentals related to this multidisciplinary scientific field. The main experimental techniques employed in state-of-art studies are described in detail in the second section followed by a third section including theoretical investigations in the field. In the next three sections, the photophysical and photochemical properties of coordination compounds, supramolecular systems and inorganic semiconductors are summarized by experts on these materials. Finally, the application of photoactive inorganic compounds in key sectors of our society is highlighted. The sections cover applications in bioimaging and sensing, drug delivery and cancer therapy, solar energy conversion to electricity and fuels, organic synthesis, environmental remediation and optoelectronics among others. The chapters provide a concise overview of the main achievements in the recent years and highlight the challenges for future research. This handbook offers a unique compilation for practitioners of inorganic photochemistry in both industry and academia.

Author : Kazuyuki Horie
Publisher : John Wiley & Sons
Page : 216 pages
File Size : 20,36 MB
Release : 2008-07-11
Category : Technology & Engineering
ISBN : 3527613218

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New organic compounds with interesting and improved electronic and photonic properties are being reported on a daily basis, with new light-triggered materials being designed for molecular and bioelectronic devices. The relatively new concept of molecular photonics embraces photochemistry and photophysics, dealing with light-induced changes in materials and their electronic states as well as the field of optics. This volume begins with a background and survey of current light-related research fields, moving on to the fundamentals of molecular photonics. Subsequent chapters deal with the characteristics of photochemical reaction and typical processes of photophysical chemistry, while the last two chapters focus on the study of materials-induced changes in light. The most important concepts are summarized in overview tables to promote active understanding of new topics. .

Author : R. Daudel
Publisher : Springer Science & Business Media
Page : 321 pages
File Size : 36,77 MB
Release : 2012-12-06
Category : Science
ISBN : 9401021562

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Proceedings of the First International Congress of Quantum Chemistry, held at Menton, France, July 4-10, 1973