Download or read book Electronic Studies of High spin Organic Molecules written by Scot Harris Bodnar and published by . This book was released on 2002 with total page 411 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: high-spin, ferromagnetic, coupling, exchange, semiquinone.
Download or read book Electronic Studies of High Spin Organic Molecules From the Effects of Substituents on Exchange Coupling to New Heterospin Species written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Design, synthesis, and characterization of novel high-spin species are critical in better understanding the field of molecular magnetism. It is also critical in advancing the field to a level of application, where new magnetic materials can be used in daily life. In this work, structure-property relationships of bis(semiquinone)s (SQ's) were studied, substituent effects on exchange coupling were investigated, and a series of novel, heterospin, complexes were synthesized and characterized. A strong comparison of exchange coupling to mixed valency is made in a bis(SQ) based on magnetic and electrochemistry data. This comparison is possible because of the isostructural species involved in the study, a Trimethylenemethane-Type (TMM) coupled bis(SQ), and a similarly mediated mixed-valent species. The sole difference between the two species being a single electron. A substituent effect was found to operate in an isostructural series of three meta-phenylene-Type (MPH), ferromagnetically coupled bis(SQ)s. Using common electron donating, withdrawing, and 'neutral' substituents, (NMe2, NO2, and t-Bu respectively) it was shown that both donating and withdrawing groups attenuate the singlet-triplet gap in the ground-state triplet species. A relatively simple HÜckle molecular orbital explanation describes the effect. It is the first time that a singlet-triplet gap of a ground-state triplet biradical has been affected by substituents. Finally, a series of new heterospin complexes consisting of a nitronyl nitroxide (NN), semiquinone (SQ), and metal (II) ion were synthesized and characterized. These species are among the limited few examples of a molecular species containing up to three entirely different spin-carriers. Also, of great importance, is the novel variation on the TMM-type coupling within the complexes. This ferromagnet coupling between the nitronyl nitroxide and the semiquinone portions of the complex is so strong (lower limit of + 310 cm−1).
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2003 with total page 860 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book World Scientific Reference On Spin In Organics In 4 Volumes written by Zeev Valy Vardeny and published by World Scientific. This book was released on 2017-12-27 with total page 1364 pages. Available in PDF, EPUB and Kindle. Book excerpt: This reference work on Spin in Organics contains four volumes dedicated to spin injection, spin transport, spin pumping, organic magnetic field effect, and molecular spintronics. The field of Organic Spintronics has accelerated and matured in the last dozen years with the realization of an organic spin-valve (in 2004) and magneto-resistance and magneto-electroluminescence in organic optoelectronic devices (2006).The book series is comprehensive in that it summarizes all aspects of Organic Spintronics to date. The first two volumes deal with spin injection, spin transport, spin manipulation and spin pumping into organic semiconductors. The main device that is thoroughly discussed here is the organic spin-valve, where spinterface states at the interface between the organic semiconductor and the ferromagnetic (FM) electrode has been the focus of many chapters. An interesting emerging subject is the role of chirality in the organic layer of the device. A relatively new method of achieving spin aligned carriers in organic semiconductors is spin pumping, where magnons in the FM substrate generate spin aligned carriers in the organic layer at the FM/organic interface.The third volume deals mainly with magnetic field effect in organic devices. Several spin-mixture processes that lead to magnetic field effect in devices and films are thoroughly discussed, such as hyperfine interaction, direct spin-orbit coupling, indirect spin-orbit coupling via Δg, triplet-triplet annihilation, and thermal spin alignment. The similarity between the magnetic field effect obtained in optoelectronic devices based on organic semiconductors and the novel hybrid organic-inorganic semiconductors is also a subject of intense interest. The fourth volume deals with spin in molecular films and devices. It includes thorough discussion of spin exchange interaction that leads to organic ferromagnets, as well as manifestation of various spin interactions in thin molecular films and devices.
Download or read book Spin Exchange written by I︠U︡riĭ Nikolaevich Molin and published by Springer. This book was released on 1980 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spin Exchange written by Y.N. Molin and published by Springer. This book was released on 1980 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spin exchange between paramagnetic particles is one of the few elementary bimolecular processes in solutions that is readily accessible to detailed experimental studies and to strict theoretical description. Due to this fact spin exchange is now widely used in solving various problems of chemistry, physics, and molecular biology. Spin exchange allows one to study in detail elementary acts of collisions of molecules. By use of spin exchange one can obtain quantitative information on collision rates of molecules in solutions, steric hinderance in collisions, electrostatic interactions in collisions of charged particles, and overlap of electron orbitals in collisions. Par ticularly valuable is the possibility of using spin exchange to study col lisions in such complex systems as polymer solutions, multicomponent mix tures, heterogeneous mixtures, and especially biological systems. This monograph contains a comprehensive description of spin exchange in solutions. It consists of four chapters. The introductory chapter contains a brief summary of the physical principles of spin exchange and outlines the range of its main applications. In this chapter a historic background of research in this field is also given. The second chapter contains a com prehensive presentation of the theory of spin exchange including that of its spectroscopic manifestations. The third chapter is devoted to a detailed description of the technique of experimental studies of spin exchange. The last - the fourth - chapter summarizes the results of experimental studies of spin exchange and considers various applications of spin exchange in che mistry, molecular physics, and biology.
Download or read book Spin orbit Coupling in Molecules written by William Graham Richards and published by Oxford University Press, USA. This book was released on 1981 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Substituent Effects on Spin Density Distribution and Exchange Coupling in Semiquinone Complexes written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Substituent Effects on the Spin exchange Interaction in Flexible Organic Biradicals written by Jonathan David Ball and published by . This book was released on 1997 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spin Injection and Manipulation in Organic Semiconductors written by Karthik Raman Venkataraman and published by . This book was released on 2011 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of organic semiconductors to enable organic spintronic devices requires the understanding of transport and control of the spin state of the carriers. This thesis deals with the above issue, focusing on the interface between the organic semiconductor and the spin source. The morphology of the organic molecule at the interface is shown to play a dominant role in this study, influencing spin injection. The interface molecule morphology affects the form of interaction between the organic molecule and the ferromagnet. This interaction ranges from a weak Van der Waals' to a chemical interaction leading to charge transfer, hybridization and other interface chemistry. As a result, the spin-dependent density of states is modified, influencing the spin injection process. The first part of the thesis focuses on identifying the interface properties between the ferromagnet and the organic semiconductor, rubrene. This is performed in a vertical organic junction geometry using different interface characterization tools. The growth morphology of the rubrene molecule is shown to influence the electronic coupling between the molecule and the ferromagnet. This has a pronounced effect on the spin injection efficiency and the magnetoresistance signals in the devices. The complex nature of the top interface is dealt with in detail. These studies provide insights on the importance of tailoring the interface properties to control and realize optimum behavior. As an alternative to conventional ferromagnets, a spin-filter material, europium sulphide, is demonstrated as a spin-polarized source. Spin-filter materials have shown the possibility to inject spin-polarized electrons into the organic semiconductor at higher voltage bias. This knowledge encouraged to seek organic spin-filter materials. Understanding the importance of molecule morphology from the work on rubrene, the second part of the thesis involved the study on a new class of organic materials called the phenalenyl compounds. Study using the compound, Zinc methyl phenalenyl, was initiated that showed large magnetoresistance signals of 50% at 4.2 K to 20% at close to room temperature. The origin of this magnetoresistance is attributed to a new interface phenomena described by the spin-filtering effect. The interface molecule morphology is found to play a very important role at the interface inducing an antiferromagnetic state and dominating the device physics. This technique opens up a new approach to engineer the interface and realize new functional devices without worrying about the bulk disorder of the organic film. This thesis thus shows the feasibility of tuning the property of the interface using tailor-made molecules to realize new functional devices at room temperature that can lead to development of the field and technological applications.
Download or read book Handbook of Spintronics written by Yongbing Xu and published by Springer. This book was released on 2015-10-14 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over two volumes and 1500 pages, the Handbook of Spintronics will cover all aspects of spintronics science and technology, including fundamental physics, materials properties and processing, established and emerging device technology and applications. Comprising 60 chapters from a large international team of leading researchers across academia and industry, the Handbook provides readers with an up-to-date and comprehensive review of this dynamic field of research. The opening chapters focus on the fundamental physical principles of spintronics in metals and semiconductors, including an introduction to spin quantum computing. Materials systems are then considered, with sections on metallic thin films and multilayers, magnetic tunnelling structures, hybrids, magnetic semiconductors and molecular spintronic materials. A separate section reviews the various characterisation methods appropriate to spintronics materials, including STM, spin-polarised photoemission, x-ray diffraction techniques and spin-polarised SEM. The third part of the Handbook contains chapters on the state of the art in device technology and applications, including spin valves, GMR and MTJ devices, MRAM technology, spin transistors and spin logic devices, spin torque devices, spin pumping and spin dynamics and other topics such as spin caloritronics. Each chapter considers the challenges faced by researchers in that area and contains some indications of the direction that future work in the field is likely to take. This reference work will be an essential and long-standing resource for the spintronics community.
Download or read book Lanthanide Single Molecule Magnets written by Jinkui Tang and published by Springer. This book was released on 2015-04-24 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book begins by providing basic information on single-molecule magnets (SMMs), covering the magnetism of lanthanide, the characterization and relaxation dynamics of SMMs and advanced means of studying lanthanide SMMs. It then systematically introduces lanthanide SMMs ranging from mononuclear and dinuclear to polynuclear complexes, classifying them and highlighting those SMMs with high barrier and blocking temperatures – an approach that provides some very valuable indicators for the structural features needed to optimize the contribution of an Ising type spin to a molecular magnet. The final chapter presents some of the newest developments in the lanthanide SMM field, such as the design of multifunctional and stimuli-responsive magnetic materials as well as the anchoring and organization of the SMMs on surfaces. In addition, the crystal structure and magnetic data are clearly presented with a wealth of illustrations in each chapter, helping newcomers and experts alike to better grasp ongoing trends and explore new directions. Jinkui Tang is a professor at Changchun Institute of Applied Chemistry, Chinese Academy of Sciences. Peng Zhang is currently pursuing his PhD at Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, with a specific focus on the molecular magnetism of lanthanide compounds under the supervision of Prof. Jinkui Tang.
Download or read book Nitroxides written by Gertz I. Likhtenshtein and published by Springer Nature. This book was released on 2020-01-03 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by a pioneer in the development of spin labeling in biophysics, this expert book covers the fundamentals of nitroxide spin labeling through cutting-edge applications in chemistry, physics, materials science, molecular biology, and biomedicine. Nitroxides have earned their place as one of the most popular organic paramagnets due to their suitability as inhibitors of oxidative processes, as a means to polarize magnetic nuclei, and, in molecular biology, as probes and labels to understand molecular structures and dynamics AS DRAGS FOR CANCER AND OTHER DISEASES. Beginning with an overview of the basic methodology and nitroxides’ 145-year history, this book equips students with necessary background and techniques to undertake original research and industry work in this growing field.
Download or read book Molecular Materials written by Duncan W. Bruce and published by John Wiley & Sons. This book was released on 2011-04-04 with total page 455 pages. Available in PDF, EPUB and Kindle. Book excerpt: “... the book does an excellent job of putting together several different classes of materials. Many common points emerge, and the book may facilitate the development of hybrids in which the qualities of the “parents” are enhanced.” –Angew. Chem. Int. Ed. 2011 With applications in optoelectronics and photonics, quantum information processing, nanotechnology and data storage, molecular materials enrich our daily lives in countless ways. These materials have properties that depend on their exact structure, the degree of order in the way the molecules are aligned and their crystalline nature. Small, delicate changes in molecular structure can totally alter the properties of the material in bulk. There has been increasing emphasis on functional metal complexes that demonstrate a wide range of physical phenomena. Molecular Materials represents the diversity of the area, encapsulating magnetic, optical and electrical properties, with chapters on: Metal-Based Quadratic Nonlinear Optical Materials Physical Properties of Metallomesogens Molecular Magnetic Materials Molecular Inorganic Conductors and Superconductors Molecular Nanomagnets Structured to include a clear introduction, a discussion of the basic concepts and up-to-date coverage of key aspects, each chapter provides a detailed review which conveys the excitement of work in that field. Additional volumes in the Inorganic Materials Series: Low-Dimensional Solids | Molecular Materials | Porous Materials | Energy Materials
Download or read book An Introduction to Nonlinear Chemical Dynamics written by Irving R. Epstein and published by Oxford University Press. This book was released on 1998-10-22 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: Just a few decades ago, chemical oscillations were thought to be exotic reactions of only theoretical interest. Now known to govern an array of physical and biological processes, including the regulation of the heart, these oscillations are being studied by a diverse group across the sciences. This book is the first introduction to nonlinear chemical dynamics written specifically for chemists. It covers oscillating reactions, chaos, and chemical pattern formation, and includes numerous practical suggestions on reactor design, data analysis, and computer simulations. Assuming only an undergraduate knowledge of chemistry, the book is an ideal starting point for research in the field. The book begins with a brief history of nonlinear chemical dynamics and a review of the basic mathematics and chemistry. The authors then provide an extensive overview of nonlinear dynamics, starting with the flow reactor and moving on to a detailed discussion of chemical oscillators. Throughout the authors emphasize the chemical mechanistic basis for self-organization. The overview is followed by a series of chapters on more advanced topics, including complex oscillations, biological systems, polymers, interactions between fields and waves, and Turing patterns. Underscoring the hands-on nature of the material, the book concludes with a series of classroom-tested demonstrations and experiments appropriate for an undergraduate laboratory.
Download or read book Spin Crossover Materials written by Malcolm A. Halcrow and published by John Wiley & Sons. This book was released on 2013-01-07 with total page 729 pages. Available in PDF, EPUB and Kindle. Book excerpt: The phenomenon of spin-crossover has a large impact on the physical properties of a solid material, including its colour, magnetic moment, and electrical resistance. Some materials also show a structural phase change during the transition. Several practical applications of spin-crossover materials have been demonstrated including display and memory devices, electrical and electroluminescent devices, and MRI contrast agents. Switchable liquid crystals, nanoparticles, and thin films of spin-crossover materials have also been achieved. Spin-Crossover Materials: Properties and Applications presents a comprehensivesurvey of recent developments in spin-crossover research, highlighting the multidisciplinary nature of this rapidly expanding field. Following an introductory chapter which describes the spin-crossover phenomenon and historical development of the field, the book goes on to cover a wide range of topics including Spin-crossover in mononuclear, polynuclear and polymeric complexes Structure: function relationships in molecular spin-crossover materials Charge-transfer-induced spin-transitions Reversible spin-pairing in crystalline organic radicals Spin-state switching in solution Spin-crossover compounds in multifunctional switchable materials and nanotechnology Physical and theoretical methods for studying spin-crossover materials Spin-Crossover Materials: Properties and Applications is a valuable resource for academic researchers working in the field of spin-crossover materials and topics related to crystal engineering, solid state chemistry and physics, and molecular materials. Postgraduate students will also find this book useful as a comprehensive introduction to the field.
Download or read book Selenium and Tellurium Chemistry written by J. Derek Woollins and published by Springer Science & Business Media. This book was released on 2011-07-28 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our knowledge of the chemistry of selenium and tellurium has seen significant progress in the last few decades. This monograph comprises contributions from leading scientists on the latest research into the synthesis, structure and bonding of novel selenium and tellurium compounds. It provides insight into mechanistic studies of these compounds and describes coordination chemistry involving selenium and tellurium containing ligands. Contributions also describe the theoretical and spectroscopic studies of selenium and tellurium compounds. Additionally, this monograph outlines the applications of selenium and tellurium in biological systems, materials science and as reagents in organic synthesis and shows how these applications have been a fundamental driving force behind the research into the inorganic and organic chemistry these fascinating elements.
