Spectroscopy of Defects in Organic Crystals

Electronic states of defects combine to form crystal near-to-band and band levels. These are discrete states in the vicinity of exciton bands, surface and dislocational excitons, etc.

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Author: N.I. Ostapenko

Publisher: Springer Science & Business Media

ISBN: 9789401116756

Category: Science

Page: 261

View: 832

Spectroscopy of Defects in Organic Crystals presents a masterly summary of the widespread and voluminous literature on the subject, presenting theoretical and experimental investigations of electron and vibronic optical spectra of organic crystals. Electronic states of defects combine to form crystal near-to-band and band levels. These are discrete states in the vicinity of exciton bands, surface and dislocational excitons, etc. Some studies have expressed dissimilar or even conflicting opinions about the nature of observed phenomena. In the choice of the material, preference has been given to phenomena which have received a theoretical interpretation. Some attention is paid to observations which are not completely understood and also to effects predicted but not yet confirmed. The monograph will be useful for scientists as well as undergraduate and postgraduate students of solid state physics.

Photosynthetic Excitons

E. A. Silinsh and V. Capek, Organic Molecular Crystals. Interaction, Localization and Transport Phenomena (AIP Press, New York, 1994). N. I. Ostapenko, V. I. Sugakov and M. T. Shpak, Spectroscopy of Defects in Organic Crystals (Kluwer ...

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Author: Herbert van Amerongen

Publisher: World Scientific

ISBN: 9789814496858

Category: Science

Page: 604

View: 708

Excitons are considered as the basic concept used by describing the spectral properties of photosynthetic pigment-protein complexes and excitation dynamics in photosynthetic light-harvesting antenna and reaction centers. Following the recently obtained structures of a variety of photosynthetic pigment-protein complexes from plants and bacteria our interest in understanding the relation between structure, function and spectroscopy has strongly increased. These data demonstrate a short interpigment distance (of the order of 1 nm or even smaller) and/or a highly symmetric (ring-like) arrangement of pigment molecules in peripheral light-harvesting complexes of photosynthetic bacteria. Books which were devoted to the exciton problem so far mainly considered the spectral properties of molecular crystals. However, the small size of these pigment aggregates in the pigment-protein complexes as well as the role of the protein, which is responsible for the structural arrangement of the complex, clearly will have a dramatic influence on the pigment spectra and exciton dynamics. All these aspects of the problem are considered in this book. Exciton theory is mainly considered for small molecular aggregates (dimers, ring-like structures etc.). Together with the theoretical description of the classical conceptual approach, which mainly deals with polarization properties of the absorption and fluorescence spectra, the nonlinear femtosecond spectroscopy which is widely used for investigations now is also discussed. A large part of the book demonstrates the excitonic effects in a multitude of photosynthetic pigment-protein complexes and how we can understand these properties on the basis of the exciton concept. Contents:Introduction: Structural Organization, Spectral Properties and Excitation Energy Transfer in PhotosynthesisThe Exciton ConceptSome Optical Properties of the Excitonically Coupled DimerMixing with Higher Excited StatesSpectral Shapes: Homogeneous and Inhomogeneous BroadeningSpectroscopy of Excitons in Molecular Crystals and AggregatesExcitonic Interactions in Photosynthetic Systems: Spectroscopic EvidenceExciton DynamicsExciton Dynamics in Different Antenna Complexes. Coherence and IncoherenceMigration of Localized Excitations: Förster Excitation Energy Transfer and Trapping by Reaction CentersExciton Energy Transfer and Trapping. ExperimentsNonlinear Annihilation of Excitons. TheoryNonlinear Annihilation of Excitons. ExperimentalNonlinear Spectroscopy Readership: Students and researchers in biophysics, condensed matter/solid state physics, atomic & molecular physics and biochemistry. keywords:Photosynthesis;Excitons;Biophysics;Excitation Energy Transfer and Trapping;Spectroscopy;Picosecond Spectroscopy;Femtosecond Spectroscopy;Polarized Spectroscopy;Exciton Dynamics;Optical Properties of Photosythetic Complexes;Homogeneous and Inhomogeneous;Broadening;Coherence and Incoherence;Nonlinear Annihilation of Excitons;Nonlinear Spectroscopy;Light Harvesting “… this is a unique book … The price is quite reasonable, and the book should not only be on the shelves of institutional libraries, but also in many private libraries and offices, where it will serve as a standard reference work for many years to come.” Photosynthesis Research

Handbook of Applied Solid State Spectroscopy

4.5.9 Paramagnetic Inorganic Ions in Organic Host Crystals In some systems under study by ENDOR techniques ... ENDOR Spectroscopy 190 Paramagnetc Inorganic Ions in Organic Host Crystals and Powders Defects and Complexes on Surfaces.

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Author: D.R. Vij

Publisher: Springer Science & Business Media

ISBN: 9780387375908

Category: Science

Page: 742

View: 353

Solid-State spectroscopy is a burgeoning field with applications in many branches of science, including physics, chemistry, biosciences, surface science, and materials science. This handbook brings together in one volume information about various spectroscopic techniques that is currently scattered in the literature of these disciplines. This concise yet comprehensive volume covers theory and applications of a broad range of spectroscopies. It provides an overview of sixteen spectroscopic technique and self-contained chapters present up-to-date scientific and technical information and references with minimal overlap and redundancy.

Organic Crystals Germanates Semiconductors

For many organic crystals lines narrow with decreasing temperature, allowing high spectral resolution at low temperature (e.g. at 4.2 K). Therefore analysis of low-temperature spectra can lead to detailed information on chemical defects ...

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Author: Norbert Karl

Publisher: Springer Science & Business Media

ISBN: 9783642677649

Category: Science

Page: 224

View: 803

1.1 Preface Organic chemistry had its origin in chemicals which are synthesized by living cells. These chemicals consist of molecules whose skeletons are built up of carbon atoms. The remaining valences are connected with ligands such as hydrogen, halo gens, -OH,==O, -NH . Some of the skeletal carbon atoms can be replaced by non 2 metals such as oxygen, nitrogen, or sulfur {"heteroatoms"}. It is characteristic for the living world, not to be in a crystalline state. However it is possible to obtain single crystals from many organic compounds both of natural and synthetic origin. For a number of years the physics and chem istry of these crystals have stimulated fundamental research on a rapidly growing scale. The great variety of possible organic structures {as compared to inorganics} opens up a large field of new materials and of novel material properties; for previous literature reviews and data compilations see 1-40) and Chap. 6. The art of producing good and pure organic single crystals has developed hand in-hand with the ever growing requirements of basic research, arising from its interest in fundamental interactions in the solid state. Interactions manifest themselves in a very detailed way by energy transfer.

Optics and Spectroscopy

On structural defects in dipole - molecule organic crystals S. V. Izvekov and V. I. Sugakov Institute for Nuclear Research , Academy of Sciences of Ukraine , 252022 , Kiev , Ukraine ( Received 23 July 1993 ) Opt . Spektrosk .

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Author:

Publisher:

ISBN: CHI:40353724

Category: Optics

Page:

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Disordered Pharmaceutical Materials

... defects 87 non-isothermal crystallization 328 normal mode, molecular origin 314 nucleation 17 o octaacetylmaltose (acMAL) 339 optical microscopy 118 on-line Raman spectroscopy 383 oral drug absorption barriers 57 organic crystals, ...

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Author: Marc Descamps

Publisher: John Wiley & Sons

ISBN: 9783527652723

Category: Science

Page: 544

View: 892

A one-stop resource for researchers, developers, and post graduate students in pharmaceutical science. This handbook and ready reference provides detailed, but not overloaded information -- presenting the topic without unnecessarily complex formalism. As such, it gives a systematic and coherent overview of disordered materials for pharmaceutical applications, covering fundamental aspects, as well as preparation and characterization techniques for the target-oriented development of drug delivery systems based on disordered crystals and amorphous solids. Special attention is paid to examine the different facets and levels of disorder in their structural and dynamic aspects as well as the effect of disorder on dissolution and stability. Chapters on processing induced disorder and on patenting issues round off the book. As a result the book helps overcoming the challenges of using these materials in the pharmaceutical industry. For pharmaceutical and medicinal chemists, materials scientists, clinical physicists, and pharmaceutical laboratories looking to make better and more potent pharmaceuticals.

Molecular Spectroscopy

Organic polymers have properties similar to that of molecular crystals. ... 'random' polymers and organic crystals with lattice defects has been described.89 Theoretical and practical aspects of vibrational spectroscopy of polymers have ...

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Author: R. F. Barrow

Publisher: Royal Society of Chemistry

ISBN: 9780851865461

Category: Reference

Page: 291

View: 731

Specialist Periodical Reports provide systematic and detailed review coverage of progress in the major areas of chemical research. Written by experts in their specialist fields the series creates a unique service for the active research chemist, supplying regular critical in-depth accounts of progress in particular areas of chemistry. For over 80 years the Royal Society of Chemistry and its predecessor, the Chemical Society, have been publishing reports charting developments in chemistry, which originally took the form of Annual Reports. However, by 1967 the whole spectrum of chemistry could no longer be contained within one volume and the series Specialist Periodical Reports was born. The Annual Reports themselves still existed but were divided into two, and subsequently three, volumes covering Inorganic, Organic and Physical Chemistry. For more general coverage of the highlights in chemistry they remain a 'must'. Since that time the SPR series has altered according to the fluctuating degree of activity in various fields of chemistry. Some titles have remained unchanged, while others have altered their emphasis along with their titles; some have been combined under a new name whereas others have had to be discontinued. The current list of Specialist Periodical Reports can be seen on the inside flap of this volume.

Organic Field Effect Transistors

... measurement for, 289 charge carrier mobility of, 270 charge injection physics of, 105 defects ... 491–492 SIMS, see Secondary ion mass spectrometry Single crystal mobility, 514 Single-crystal organic field-effect transistors, ...

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Author: Zhenan Bao

Publisher: CRC Press

ISBN: 9781420008012

Category: Technology & Engineering

Page: 640

View: 470

The remarkable development of organic thin film transistors (OTFTs) has led to their emerging use in active matrix flat-panel displays, radio frequency identification cards, and sensors. Exploring one class of OTFTs, Organic Field-Effect Transistors provides a comprehensive, multidisciplinary survey of the present theory, charge transport studies, synthetic methodology, materials characterization, and current applications of organic field-effect transistors (OFETs). Covering various aspects of OFETs, the book begins with a theoretical description of charge transport in organic semiconductors at the molecular level. It then discusses the current understanding of charge transport in single-crystal devices, small molecules and oligomers, conjugated polymer devices, and charge injection issues in organic transistors. After describing the design rationales and synthetic methodologies used for organic semiconductors and dielectric materials, the book provides an overview of a variety of characterization techniques used to probe interfacial ordering, microstructure, molecular packing, and orientation crucial to device performance. It also describes the different processing techniques for molecules deposited by vacuum and solution, followed by current technological examples that employ OTFTs in their operation. Featuring respected contributors from around the world, this thorough, up-to-date volume presents both the theory behind OFETs and the latest applications of this promising technology.

Biomedical Engineering

We originally proposed and demonstrated that defects in organic crystals can be detected as slight peak frequency shifts in the absorption lines of THz spectra, and that the magnitudes of these shifts are dependent on the defect ...

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Author: Akihiro Miyauchi

Publisher: CRC Press

ISBN: 9781000333749

Category: Medical

Page: 396

View: 491

Several developed countries are facing serious problems in medical environments owing to the aging society, and extension of healthy lifetime has become a big challenge. Biomedical engineering, in addition to life sciences and medicine, can help tackle these problems. Innovative technologies concerning minimally invasive treatment, prognosis and early diagnosis, point-of-care testing, regenerative medicine, and personalized medicine need to be developed to realize a healthy aging society. This book presents cutting-edge research in biomedical engineering from materials, devices, imaging, and information perspectives. The contributors are senior members of the Research Center for Biomedical Engineering, supported by the Ministry of Education, Culture, Sports, Science and Technology, Japan. All chapters are results of collaborative research in engineering and life sciences and cover nanotechnology, materials, optical sensing technology, imaging technology, image processing technology, and biomechanics, all of which are important areas in biomedical engineering. The book will be a useful resource for researchers, students, and readers who are interested in biomedical engineering.

Fourier Transform Infrared Spectra

... of crystalline polymorphs, molecular and crystal structure analysis, the determination of phase changes, compressibilities, vibrational anharmonicities, magnetic and ferroelectric modes, and defects in organic crystals.

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Author: John R. Ferraro

Publisher: Elsevier

ISBN: 9780323140171

Category: Science

Page: 311

View: 286

Fourier Transform Infrared Spectroscopy: Applications to Chemical Systems presents the chemical applications of the Fourier transform interferometry (FT-IR). The book contains discussions on the applications of FT-IR in the fields of chromatography FT-IR, polymers and biological macromolecules, emission spectroscopy, matrix isolation, high-pressure interferometry, and far infrared interferometry. The final chapter is devoted to the presentation of the use of FT-IR in solving national technical problems such as air pollution, space exploration, and energy related subjects. Research and analytical chemists will find the book insightful.