Author: Christopher Patrick Price
Publisher:
ISBN:
Category :
Languages : en
Pages : 322

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Book Description

Author: Yongfang Li
Publisher: Springer
ISBN: 3319168622
Category : Technology & Engineering
Languages : en
Pages : 402

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Book Description
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.

Author: Rui Tamura
Publisher: Springer
ISBN: 4431555552
Category : Science
Languages : en
Pages : 699

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Book Description
For the last decade, the topics of organic crystal chemistry have become diversified, and each topic has been substantially advanced in concert with the rapid development of various analytical and measurement techniques for solid-state organic materials. The aim of this book is to systematically summarize and record the recent notable advances in various topics of organic crystal chemistry involving liquid crystals and organic–inorganic hybrid materials that have been achieved mainly in the last 5 years or so. The authors are invited members of the Division of Organic Crystals, The Chemical Society of Japan (CSJ), and prominent invited experts from abroad. This edited volume is planned to be published periodically, at least every 5 years, with contributions by prominent authors in Japan and from abroad.

Author: Xiaochuan Yang (Ph. D.)
Publisher:
ISBN:
Category :
Languages : en
Pages : 164

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Book Description
The formation of organic molecular nanocrystals is a topic of great interest in the pharmaceutical industry because of the potential increase in dissolution rate and solubility of organic crystals below 1 ptm and their potential use in drug products. Previous investigators have developed various methods to produce them; however, breakage, high supersaturation and high intensity mixing are often involved in those methods, producing amorphous solids and if crystalline solid is obtained making control of desired polymorphs difficult. The aim of this thesis is to: (1) Evaluate practical methods to produce organic molecular nano-crystals of the desired form; (2) determine the change in crystal solid properties with size; (3) develop a better fundamental understanding of nucleation kinetics during concomitant nucleation of polymorphs. The first approach tried used bi-functional Self-Assembled Monolayers (SAMs) substrates. Using mefenamic acid as the model compound, micro-sized and nano-sized crystals were obtained with controlled polymorphs and narrow size distributions. By tuning experimental conditions and surface chemistry, exclusive production of one polymorph was demonstrated as well. On the 1 ptm gold islands a single crystal was obtained on each of the islands with a crystal size of ~ 300 nm. The second approach is crystallization under nano-sized confinement. Using soft confinement (porous polymer membranes), we reported the use of a novel solution impregnation method to form nanocrystals in polymer matrices with various microstructures to systemically study the role of soft confinement and polymer chemistry on the nucleation process of nano-sized crystals. We obtained 100% crystalline materials of four compounds in all experiments and in most cases nanocrystals were the most stable form. The smallest nanocrystals produced were ~ 100 nm. In the rigid confinement (porous silica particles of ~ 40nm pores), we explored the polymorphic outcome of four different compounds using solid state NMR. We found that three out of the four compounds can crystallize in the pores although one showed two polymorphs concomitantly crystallized the same time and another one produces a mixture of two polymorphs and amorphous states. All these nanocrystals under soft and rigid confinement showed significant enhancement of dissolution profiles. These results help advance the fundamental understanding of nucleation under rigid confinement and may lead to potential applications in developing new formulations in the pharmaceutical industry. The third approach is the use of nano spray drying. We used glycine as the model compound and compare this approach with the first one we developed, and the results suggest that the nanocrystals produced by spraying exhibit wider size distribution and worse surface structures. These defects existing on crystal surface may improve mobility of molecules and cause "crystal-bridging" to form big crystals. To explore the change in crystal solid properties regarding size, we also measured the solubility vs size curves of two polymorphs of glycine. Both polymorphs showed 20%-30% increase of solubility when crystal size goes down to -300 nm. Although the curves did not cross in the range that we measured, the extended trends suggested that p-glycine solubility could be lower than [beta]-glycine when the crystal size is smaller than ~100 nm.

Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 868

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Author: Michael Harmata
Publisher: Elsevier
ISBN: 0080556027
Category : Science
Languages : en
Pages : 537

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Book Description
A classic in the area of organic synthesis, Strategies and Tactics in Organic Synthesis provides a forum for investigators to discuss their approach to the science and art of organic. Rather than a simple presentation of data or a second-hand analysis, we are given stories that vividly demonstrate the power of the human endeavour known as organic synthesis and the creativity and tenacity of its practitioners. First hand accounts of each project tell of the excitement of conception, the frustration of failure and the joy experienced when either rational thought and/or good fortune give rise to successful completion of a project. In this book we learn how synthesis is really done and are educated, challenged and inspired by these stories, which portray the idea that triumphs do not come without challenges. We also learn that we can meet challenges to further advance the science and art of organic synthesis, driving it forward to meet the demands of society, in discovering new reactions, creating new designs and building molecules with atom and step economies that provide solutions through function to create a better world. * Presents state-of-the-art developments in organic synthesis * Provides insight and offers new perspective to problem-solving * Written by leading experts in the field

Author: Kevin J. Roberts
Publisher: Springer
ISBN: 9402411178
Category : Science
Languages : en
Pages : 481

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Book Description
This book highlights the current state-of-the-art regarding the application of applied crystallographic methodologies for understanding, predicting and controlling the transformation from the molecular to crystalline state with the latter exhibiting pre-defined properties. This philosophy is built around the fundamental principles underpinning the three inter-connected themes of Form (what), Formation (how) and Function (why). Topics covered include: molecular and crystal structure, chirality and ferromagnetism, supramolecular assembly, defects and reactivity, morphology and surface energetics. Approaches for preparing crystals and nano-crystals with novel physical, chemical and mechanical properties include: crystallisation, seeding, phase diagrams, polymorphic control, chiral separation, ultrasonic techniques and mechano-chemistry. The vision is realised through examination of a range of advanced analytical characterisation techniques including in-situ studies. The work is underpinned through an unprecedented structural perspective of molecular features, solid-state packing arrangements and surface energetics as well as in-situ studies. This work will be of interest to researchers, industrialists, intellectual property specialists and policy makers interested in the latest developments in the design and supply of advanced high added-value organic solid-form materials and product composites.

Author: Fumio Toda
Publisher: Springer Science & Business Media
ISBN: 9401700893
Category : Science
Languages : en
Pages : 279

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Book Description
Most organic reactions have long been carried out in organic solvents without concern for their real necessity, reaction efficiency, and pollution problems. Very recently, we have found that most organic reactions can be carried out in the absence of a solvent, namely, in the solid state. In many cases, the solid-state reaction proceeds more easily and efficiently, and even more selectively than solution reaction. This shows that molecules move easily and selectively in the solid state. This finding changed the classical idea which suggests "molecules do not move and reactions do not occur in the solid state", and opened up a new research field for the study molecular dynamics in the solid state. The organic solid state reactions have many possibilities to be developed. For example, enantioselective reactions can easily be accomplished by carrying out the reaction in an inclusion complex crystal with an optically active host compound. Catalytic reactions also proceed in the solid state. Moreover, the solid-state reactions are more economical and ecologically sound. In the future, pollution-free synthetic procedures in the solid state will become increasingly important, not only in chemical industries but also in university laboratories.

Author: Norbert Karl
Publisher: Springer Science & Business Media
ISBN: 3642762530
Category : Science
Languages : en
Pages : 169

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Book Description
Lattice defects of organic molecular crystals affect their optical or electrical properties by changing the local energy structure. Lattice defects also playa very important role in the chemical and physical properties, for example, as an active site of a catalyst or an initiating point of a solid state reaction. However, very little has been reported on the defect structure of real organic crystals. In the past ten years it became clear that the origin and the structure of the defects depend on the geometrical and chemical nature of the building units of the crystal, the molecules. Molecular size, form and anisotropy, charge distribution, etc. cause the characteristic structure of the defect. Accordingly, a defect structure found in one compound may not be found in others. The defect structure of an organic crystal cannot be defined solely by the displacement of the molecular center from the normal lattice site. A rotational displacement of a molecule is frequently accompanied by a parallel shift of the molecular center. In addition to the usual geometrical crystallographic defects, chemical defects are important too which originate, for example, from differences in the substitution sites of molecules carrying side groups. In order to reveal such defect structures, direct imaging of molecules by high resolution electron microscopy is the only direct method.

Author: Tong Li
Publisher: John Wiley & Sons
ISBN: 1119046297
Category : Science
Languages : en
Pages : 432

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Book Description
An important resource that puts the focus on understanding and handling of organic crystals in drug development Since a majority of pharmaceutical solid-state materials are organic crystals, their handling and processing are critical aspects of drug development. Pharmaceutical Crystals: Science and Engineering offers an introduction to and thorough coverage of organic crystals, and explores the essential role they play in drug development and manufacturing. Written contributions from leading researchers and practitioners in the field, this vital resource provides the fundamental knowledge and explains the connection between pharmaceutically relevant properties and the structure of a crystal. Comprehensive in scope, the text covers a range of topics including: crystallization, molecular interactions, polymorphism, analytical methods, processing, and chemical stability. The authors clearly show how to find solutions for pharmaceutical form selection and crystallization processes. Designed to be an accessible guide, this book represents a valuable resource for improving the drug development process of small drug molecules. This important text: Includes the most important aspects of solid-state organic chemistry and its role in drug development Offers solutions for pharmaceutical form selection and crystallization processes Contains a balance between the scientific fundamental and pharmaceutical applications Presents coverage of crystallography, molecular interactions, polymorphism, analytical methods, processing, and chemical stability Written for both practicing pharmaceutical scientists, engineers, and senior undergraduate and graduate students studying pharmaceutical solid-state materials, Pharmaceutical Crystals: Science and Engineering is a reference and textbook for understanding, producing, analyzing, and designing organic crystals which is an imperative skill to master for anyone working in the field.