Download or read book The Design and Synthesis of Organic Chromophores for Faraday Rotation and Photoluminescence written by Zachary Nelson and published by . This book was released on 2021 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis summarizes the design, synthesis, and application of novel small-molecule and polymeric materials, with emphasis on understanding and tuning the chromophore electronic structure to maximize properties including Faraday rotation and delayed fluorescence. In Chapter 1, we introduce the magneto-optical property Faraday rotation. The current frontiers in performance, applications, and mechanistic understanding of Faraday rotation in organic-chromophore thin-films is discussed. Faraday rotation measurements of several novel materials are introduced in context. In Chapter 2, we evaluate the Faraday rotation in thin films of several phthalocyanine and porphyrin derivatives, and observe maximum Verdet constants greater than those found in competing inorganic materials. The effect of chemical modifications, including the introduction of paramagnetic and chiral centers, is discussed. In Chapter 3, we evaluate the Faraday rotation in thin films of pi-conjugated polymers when influenced by chiral moieties. We demonstrate the key role chirality serves in the magneto-optical properties of these materials, the influence of structural order and film thickness on Faraday rotation, and report among the largest Verdet constants observed to date in organic thin films. In Chapter 4, we develop the polymerization for and evaluate the properties of a new class of polyarylene chalcogenides. We utilized dynamic covalent SNAr behavior to demonstrate selective depolymerization. In addition, we studied the mechanism of the bright photoemission, ascribing it to delayed fluorescence enabled by the presence of sulfur atoms. In Chapter 5, we discuss the synthesis and properties of two classes of solution-processable materials: M(III) and Au(I) arylthiolate coordination polymers. We demonstrate the presence of strong metal-metal interactions between M(III) centers along the polymer backbone. Further, we discuss the strong phosphorescence and dynamic supramolecular coordination in the solution phase of the Au(I) coordination polymers.
Download or read book Design and Synthesis of Organic Chromophores for Imaging Lithography and Organic Electronics written by Trisha Lionel Andrew and published by . This book was released on 2011 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: The absorption and emission maxima, photostabilities and photoreactivities of small-molecule organic chromophores can be tailored by (a) the choice of an appropriate parent structure and (b) the deliberate introduction of substituents that predictably alter the optical properties and photochemistry of this parent structure. Suitably-designed chromophores can be used in a variety of applications, such as imaging (for example, as fluorescent labeling agents or as indicators for specific analytes), optical lithography and as active components in organic electronic devices. In Chapter 1, a fluorogenic chemosensor to detect saturated nitramine and nitrate ester explosives was devised based on a photochemical reduction reaction. 10-Methyl-9,10- dihydroacridine (AcrH2) was found to transfer a hydride ion equivalent to the high explosives RDX and PETN upon irradiation at 313 nm in degassed acetonitrile solutions. Mechanistic photophysical studies indicated that the photoreduction of RDX proceeded via a two-step electron-hydrogen atom transfer reaction, whereas PETN photoreduction proceeded via a threestep electron-proton-electron transfer sequence. A zinc analog was synthesized and found to display an 80- or 25-fold increase in 480 nm emission intensity upon reaction with RDX or PETN, respectively; moreover, the Zn analog was found to be unresponsive to TNT and other common contaminants, in addition to being photostable under ambient conditions. In Chapter 2, the nitramine-containing explosive RDX and the nitroester-containing explosive PETN were shown to be susceptible to photodegradation upon exposure to sunlight. The products of this photodegradation were identified as reactive, electrophilic NOx species, such as nitrous and nitric acid, nitric oxide, and nitrogen dioxide. NN-Dimethylaniline was capable of being nitrated by the reactive, electrophilic NOx photodegradation products of RDX and PETN. A series of 9,9-disubstituted 9,10-dihydroacridines (DHAs) were synthesized from either N-phenylanthranilic acid methyl ester or a diphenylamine derivative and were similarly shown to be rapidly nitrated by the photodegradation products of RDX and PETN. An increase in the emission signal at 550 nm was observed upon nitration of DHAs due to the generation of fluorescent donor-acceptor chromophores. Using fluorescence spectroscopy, the presence of ca. 1.2 ng of RDX and 320 pg of PETN could be detected by DHA indicators in the solid state upon exposure to sunlight. In Chapter 3, optical lithography with organic photochromes is demonstrated. In the past, the formation of microscale patterns in the far field by light has been diffractively limited in resolution to roughly half the wavelength of the radiation used. We demonstrated lines with an -4- average width of 36 nm, about one-tenth the illuminating wavelength ( 11 = 325 nm), made by applying a film of thermally-stable photochromic molecules above the photoresist. Simultaneous irradiation of a second wavelength (k= 633 nm) rendered the film opaque to the writing beam except at nodal sites, which let through a spatially constrained segment of incident 1 light, allowing subdiffractional patterning. In Chapter 4, rylene dyes functionalized with varying numbers of phenyl trifluorovinylether (TFVE) moieties were subjected to a thermal emulsion polymerization to yield shape-persistent, water-soluble chromophore nanoparticles. Perylene and terrylene diimide derivatives containing either two or four phenyl TFVE functional groups were synthesized and subjected to thermal emulsion polymerization in tetraglyme. Dynamic light scattering measurements indicated that particles with sizes ranging from 70 - 100 nm were obtained in tetraglyme, depending on monomer concentration. The photophysical properties of individual monomers were preserved in the nanoemulsions and emission colors could be tuned between yellow, orange, red, and deep red. The nanoparticles retained their shape upon dissolution into water and the resulting water suspensions displayed moderate to high fluorescence quantum yield, thus making them attractive candidates for bioimaging applications. In Chapter 5, a series of substituted 6,6-dicyanofulvenes (DCFs) were synthesized starting from masked, dimeric or monomeric cyclopentadienones. DCFs lacking sufficient steric bulk around the fulvene core tended to reversibly undergo a [4+2] dimerization. In addition to being highly crystalline, DCFs were darkly-colored compounds due to the presence of weak electronic transitions in the visible region of the electromagnetic spectrum. DCFs displayed two distinct, reversible one-electron reductions by cyclic voltammetry. Based on their high crystallinity and suitable electron affinities, and buoyed by their relatively cheap and straightforward synthesis, DCFs are interesting candidates for organic electron-transport materials.
Download or read book Design and Synthesis of Organic and Organometallic pi conjugated Donor acceptor Chromophores written by 陳展耀 and published by . This book was released on 2015 with total page 355 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Exploration of Supramolecular Systems and Nanostructures by Photochemical Techniques written by Paola Ceroni and published by Springer Science & Business Media. This book was released on 2011-11-01 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Exploration of Supramolecular Systems and Nanostructures by Photochemical Techniques provides a comprehensive view of the most commonly used photochemical and photophysical techniques and their applications to the study of supramolecular systems. Optical inputs are extremely powerful in the study of nanostructures since they can be used both to “read” the state of the system and to provide it energy to work. After a brief introduction to the realm of photochemistry, electronically excited state formation and the different pathways of excited state deactivation, the book focuses on the theoretical basis and the practical aspects related to the most widely used photophysical and photochemical techniques, from absorption to time-resolved emission techniques with polarized light. Each chapter illustrates an example of the application of that particular technique to the study of a supramolecular system. The Exploration of Supramolecular Systems and Nanostructures by Photochemical Techniques not only discusses the latest advances of the field of supramolecular photochemistry but it also offers technical and operative details useful in the laboratory. It is therefore suitable for both the novice and the expert.
Download or read book Light Emitting Electrochemical Cells written by Rubén D. Costa and published by Springer. This book was released on 2017-07-31 with total page 371 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the recent achievements towards the next generation of Light-emitting electrochemical cells (LEC). Its first part focus on the definition, history and mechanism of LEC, going then to concepts and challenges and, finally, giving the reader examples of current application of new electroluminescent materials. The chapters are written by different international groups working on LEC.
Download or read book Magneto Optical Imaging written by Tom H. Johansen and published by Springer Science & Business Media. This book was released on 2004-05-31 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magneto-Optical Imaging has developed rapidly over the last decade to emerge as a leading technique to directly visualise the static and dynamic magnetic behaviour of materials, capable of following magnetic processes on the scale of centimeters to sub-microns and at timescales from hours to nanoseconds. The images are direct, real-time, and give space-resolved information, such as ultrafast magnetic processes and revealing the motion of individual vortices in superconductors. The book is a fully up-to-date report of the present status of the technique.
Download or read book Principles of Fluorescence Spectroscopy written by Joseph R. Lakowicz and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 487 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fluorescence methods are being used increasingly in biochemical, medical, and chemical research. This is because of the inherent sensitivity of this technique. and the favorable time scale of the phenomenon of fluorescence. 8 Fluorescence emission occurs about 10- sec (10 nsec) after light absorp tion. During this period of time a wide range of molecular processes can occur, and these can effect the spectral characteristics of the fluorescent compound. This combination of sensitivity and a favorable time scale allows fluorescence methods to be generally useful for studies of proteins and membranes and their interactions with other macromolecules. This book describes the fundamental aspects of fluorescence. and the biochemical applications of this methodology. Each chapter starts with the -theoreticalbasis of each phenomenon of fluorescence, followed by examples which illustrate the use of the phenomenon in the study of biochemical problems. The book contains numerous figures. It is felt that such graphical presentations contribute to pleasurable reading and increased understand ing. Separate chapters are devoted to fluorescence polarization, lifetimes, quenching, energy transfer, solvent effects, and excited state reactions. To enhance the usefulness of this work as a textbook, problems are included which illustrate the concepts described in each chapter. Furthermore, a separate chapter is devoted to the instrumentation used in fluorescence spectroscopy. This chapter will be especially valuable for those perform ing or contemplating fluorescence measurements. Such measurements are easily compromised by failure to consider a number of simple principles.
Download or read book Organic Optoelectronic Materials written by Yongfang Li and published by Springer. This book was released on 2015-05-30 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume reviews the latest trends in organic optoelectronic materials. Each comprehensive chapter allows graduate students and newcomers to the field to grasp the basics, whilst also ensuring that they have the most up-to-date overview of the latest research. Topics include: organic conductors and semiconductors; conducting polymers and conjugated polymer semiconductors, as well as their applications in organic field-effect-transistors; organic light-emitting diodes; and organic photovoltaics and transparent conducting electrodes. The molecular structures, synthesis methods, physicochemical and optoelectronic properties of the organic optoelectronic materials are also introduced and described in detail. The authors also elucidate the structures and working mechanisms of organic optoelectronic devices and outline fundamental scientific problems and future research directions. This volume is invaluable to all those interested in organic optoelectronic materials.
Download or read book Effects of Light on Materials in Collections written by Terry T. Schaeffer and published by Getty Publications. This book was released on 2001-08-16 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: The impact of light on works of art and archival materials has long been an issue of concern to conservators and other museum professionals, yet the literature on this subject has never been systematically reviewed. This volume fills that gap by providing a survey of the impact of exposure to light with an emphasis on photoflash and reprographic sources. The information provided will assist the professional audience, especially conservators and collections managers, in assessing the risk to art and archival objects of such exposures. The text surveys relevant photophysical and photochemical principles, photometric and radiometric measurement, and the spectral outputs of several light sources. Materials discussed include colorants and natural fibers; pulp, paper, and wood; natural and synthetic polymers; fluorescent whitening agents; photographic and reprographic materials; and objects containing combinations of materials. Approximations and assumptions used in the evaluation process are discussed in some detail, with examples of the different types of calculations. The Research in Conservation reference series presents the findings of research conducted by the Getty Conservation Institute and its individual and institutional research partners, as well as state-of-the-art reviews of conservation literature. Each volume covers a topic of current interest to conservators and conservation scientists.
Download or read book Iridium III in Optoelectronic and Photonics Applications written by Eli Zysman-Colman and published by John Wiley & Sons. This book was released on 2017-03-07 with total page 736 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fundamental photophysical properties of iridium(III) materials make this class of materials the pre-eminent transition metal complex for use in optoelectronic applications. Iridium(III) in Optoelectronic and Photonics Applications represents the definitive account of photoactive iridium complexes and their use across a wide variety of applications. This two-volume set begins with an overview of the synthesis of these complexes and discusses their photophysical properties. The text highlights not only mononuclear complexes but also the properties of multinuclear and polymeric iridium-based materials and the assembly of iridium complexes into larger supramolecular architectures such as MOFs and soft materials. Chapters devoted to the use of these iridium-based materials in diverse optoelectronic applications follow, including: electroluminescent devices such as organic light emitting diodes (OLEDs) and light-emitting electrochemical cells (LEECs); electrochemiluminescence (ECL); bioimaging; sensing; light harvesting in the context of solar cell applications; in photoredox catalysis and as components for solar fuels. Although primarily targeting a chemistry audience, the wide applicability of these compounds transcends traditional disciplines, making this text also of use to physicists, materials scientists or biologists who have interests in these areas.
Download or read book Organic Electroluminescence written by Zakya H. Kafafi and published by CRC Press. This book was released on 2018-10-03 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic light-emitting diode(OLED) technology has achieved significant penetration in the commercial market for small, low-voltage and inexpensive displays. Present and future novel technologies based on OLEDs involve rigid and flexible flat panel displays, solid-state lighting, and lasers. Display applications may range from hand-held devices to large flat panel screens that can be rolled up or hung flat on a wall or a ceiling. Organic Electroluminescence gives an overview of the on-going research in the field of organic light-emitting materials and devices, covering the principles of electroluminescence in organic thin films, as well as recent trends, current applications, and future potential uses. The book begins by giving a background of organic electroluminescence in terms of history and basic principles. It offers details on the mechanism(s) of electroluminescence in thin organic films. It presentsin-depth discussions of the parameters that control the external electroluminescence quantum efficiency including the photoluminescence quantum yield, the light-output coupling factor, carrier/charge injection and transport, and electron and hole recombination processes in organic semiconductors. The authors address the design and the characterization of amorphous charge transport materials with high glass transition temperatures, light-emitting small molecules and conjugated polymers. The book covers state-of-the-art concepts and technologies such as fluorescent and phosphorescent OLEDs, various approaches for patterning organics, and active matrix organic emissive displays including their back panel thin film transistors and pixel electronics. It concludes by summarizing future directions for OLEDs in organic light-emitting displays, large area distributed solid state light sources, and lasers using organic thin films, nanostructures, and photonic crystals. Organic Electroluminescence is an excellent resource and reference for stu
Download or read book Introduction to Fluorescence Sensing written by Alexander P. Demchenko and published by Springer Nature. This book was released on 2020-12-01 with total page 673 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides systematic knowledge of basic principles in the design of fluorescence sensing and imaging techniques together with critical analysis of recent developments. Fluorescence is the most popular technique in chemical and biological sensing because of its ultimate sensitivity, high temporal and spatial resolution and versatility that enables imaging within the living cells. It develops rapidly in the directions of constructing new molecular recognition units, new fluorescence reporters and in improving sensitivity of response up to detection of single molecules. Its application areas range from control of industrial processes to environment monitoring and clinical diagnostics. Being a guide for students and young researchers, it also addresses professionals involved in active basic and applied research. Making a strong link between education, research and product development, this book discusses prospects for future progress.
Download or read book The Nature of the Mechanical Bond written by Carson J. Bruns and published by John Wiley & Sons. This book was released on 2016-11-07 with total page 788 pages. Available in PDF, EPUB and Kindle. Book excerpt: “The story is told by THE inventor-pioneer-master in the field and is accompanied by amazing illustrations… [it] will become an absolute reference and a best seller in chemistry!” Alberto Credi “… the great opus on the mechanical bond. A most impressive undertaking!” Jean-Marie Lehn Congratulations to co-author J. Fraser Stoddart, a 2016 Nobel Laureate in Chemistry. In molecules, the mechanical bond is not shared between atoms—it is a bond that arises when molecular entities become entangled in space. Just as supermolecules are held together by supramolecular interactions, mechanomolecules, such as catenanes and rotaxanes, are maintained by mechanical bonds. This emergent bond endows mechanomolecules with a whole suite of novel properties relating to both form and function. They hold unlimited promise for countless applications, ranging from their presence in molecular devices and electronics to their involvement in remarkably advanced functional materials. The Nature of the Mechanical Bond is a comprehensive review of much of the contemporary literature on the mechanical bond, accessible to newcomers and veterans alike. Topics covered include: Supramolecular, covalent, and statistical approaches to the formation of entanglements that underpin mechanical bonds in molecules and macromolecules Kinetically and thermodynamically controlled strategies for synthesizing mechanomolecules Chemical topology, molecular architectures, polymers, crystals, and materials with mechanical bonds The stereochemistry of the mechanical bond (mechanostereochemistry), including the novel types of dynamic and static isomerism and chirality that emerge in mechanomolecules Artificial molecular switches and machines based on the large-amplitude translational and rotational motions expressed by suitably designed catenanes and rotaxanes. This contemporary and highly interdisciplinary field is summarized in a visually appealing, image-driven format, with more than 800 illustrations covering both fundamental and applied research. The Nature of the Mechanical Bond is a must-read for everyone, from students to experienced researchers, with an interest in chemistry’s latest and most non-canonical bond. Read the Preface
Download or read book Nanomaterials Chemistry written by C. N. R. Rao and published by John Wiley & Sons. This book was released on 2007-09-24 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: With this handbook, the distinguished team of editors has combined the expertise of leading nanomaterials scientists to provide the latest overview of this field. They cover the whole spectrum of nanomaterials, ranging from theory, synthesis, properties, characterization to application, including such new developments as quantum dots, nanoparticles, nanoporous materials, nanowires, nanotubes, and nanostructured polymers. The result is recommended reading for everybody working in nanoscience: Newcomers to the field can acquaint themselves with this exciting subject, while specialists will find answers to all their questions as well as helpful suggestions for further research.
Download or read book Multiporphyrin Arrays written by Dongho Kim and published by CRC Press. This book was released on 2012-01-12 with total page 817 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive review of the fundamentals and applications of multiporphyrin arrays ranging from basic spectroscopic features to a wide range of promising applications such as molecular wires, switches, sensors, artificial photosynthetic devices, and dye-sensitized solar cells based on a variety of multiporphyrin architectures u
Download or read book Molecular Machines and Motors written by J.-P. Sauvage and published by Springer Science & Business Media. This book was released on 2001-07-03 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: This series presents critical reviews of the present position and future trends in modern chemical research. It consists of short and concise reports on chemistry, each written by the world’s renowned experts, and still valid and useful after 5 or 10 years.
Download or read book Organic Semiconducting Polymers written by J. E. Katon and published by . This book was released on 1968 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:
