Download or read book Coordination driven 2 2 metallo macrocycles isomers conformational control and photophysical properties written by Yunting Zeng and published by OAE Publishing Inc.. This book was released on 2022-06-30 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, fluorescent supramolecular materials have received significant attention due to their wide application prospects. However, the relationship between the conformation of supramolecules and their photophysical properties remains an open question. In this study, two rhomboidal metallacycle isomers, SA and SB, self-assembled with trans- and cis-isomers of tetraphenylethylene-based ditopic pyridyl ligands (LA and LB), and a 120° di-platinum (II) acceptor were prepared. Compared with metallacycle SB constructed by cis- tetraphenylethylene (TPE)-based ligand LB, the curved rhomboidal metallacycle SA constructed with trans-TPE-based ligand LA can restrict molecular motions of the aromatic groups on TPE and exhibits better light-emitting properties. Moreover, curved SA also exhibited better fluorescence stability than isomer SB towards molecules with strongly electron-withdrawing groups. This work provides a new platform to explore the relationship between conformation and the corresponding photophysical properties.
Download or read book Metallomacrocycles written by Hai-Bo Yang and published by Royal Society of Chemistry. This book was released on 2018-10-05 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive overview of metallomacrocycles from designing complex functional metallosupramolecular systems to their applications.
Download or read book Metallo Supramolecular Polymers written by Masayoshi Higuchi and published by Springer Nature. This book was released on 2019-11-12 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the synthesis, electrochemical and photochemical properties, and device applications of metallo-supramolecular polymers, new kinds of polymers synthesized by the complexation of metal ions and organic ditopic ligands. Their electrochemical and photochemical properties are also interesting and much different from conventional organic polymers. The properties come from the electronic intra-chain interaction between the metal ions and the ligands in the polymer chain. In this book, for example, the electrochromism that the Fe(II)-based metallo-supramolecular polymer exhibits is described: the blue color of the polymer film disappears by the electrochemical oxidation of Fe(II) ions to Fe(III) and the colorless film becomes blue again by the electrochemical reduction of Fe(III) to Fe(II). The electrochromism is explained by the disappearance/appearance of the metal-to-ligand charge transfer absorption. The electrochromic properties are applicable to display devices such as electronic paper and smart windows.
Download or read book Expanded Contracted Isomeric Porphyrins written by J.L. Sessler and published by Elsevier. This book was released on 1997-08-21 with total page 533 pages. Available in PDF, EPUB and Kindle. Book excerpt: The porphyrins are a class of naturally-occurring macrocycles and are ubiquitous in our world. As such, they have been called the Pigments of Life. This auspicious designation reflects their importance in numerous biological functions. Indeed, life as we understand it relies on the full range of biological processes that are either performed by or catalyzed by porphyrin-containing proteins. Chlorophyll-containing photosynthetic reaction centers in plants, for instance, convert light energy into chemical energy while producing oxygen along the way. It is this oxygen, evolved from photosynthesis, that is transported, stored, and reduced by heme-containing proteins in many organisms, including mammals. Not surprisingly, therefore, these molecules remain of fundamental interest to chemists and biochemists. Indeed, they continue to be intensely investigated by researchers world-wide. Inspired by the importance of the porphyrins, a new research direction has emerged in recent years that is devoted to the preparation and study of non-porphyrin polypyrrole macrocycles. Here, the principal objectives have been to generate completely synthetic systems that bear some structural resemblance to naturally-occurring porphyrin derivatives while being quite different in their specific chemical makeup. Within this context, three different research directions have evolved, namely those involving the syntheses of contracted, isomeric, and expanded porphyrins, respectively. It is the chemistry of these systems that is the subject of this book. Because of the newness of the field, the emphasis of this book will be on synthesis and characterization (all work on porphyrin isomers and much of that associated with expanded porphyrins has only appeared in the last 10 years). One chapter on applications has, however, been included. Also, in the context of the preparative portions of the text, some efforts have been made to explain why various porphyrin analogue targets are of interest.
Download or read book Chirality in Drug Design and Synthesis written by C. Brown and published by Academic Press. This book was released on 2013-10-22 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chirality in Drug Design and Synthesis is a collection of papers that discusses the property of asymmetry in the structural and synthetic chemistry of natural products, including the significance of chirality in medicinal chemistry. These papers examine the need for the preparation and study of pure enantiomers of chiral drug substances and their mechanism of interaction with enzymes and receptors. These papers also investigate the techniques in studying these interactions, as well as analyze the methods for their synthesis in enantiomerically pure form. One paper discusses the pharmacological and pharmacokinetic analyses made that point to the differences in the activity and disposition of enantiometric pairs. Another paper reviews the implications of the neglect of stereoselectivity at the different levels during the examination process of racemic drugs. Since no general guidelines exists for the development of drugs with chiral centers, one paper suggests a case-by-case approach in evaluating the safety and efficacy of drugs, particularly as regards how isomers differ in their effects. This collection is suitable for the pharmacologist, medicinal chemists, toxicologists, mechanistic chemists and synthetic organic chemists.
Download or read book An Ion Exchange Study of Possible Hybridized 5f Bonding in the Actinides written by R. M. Diamond and published by . This book was released on 1953 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study has been made of the elution behavior of curium(III), americium(III), plutonium(III), actinium(III), plutonium(IV), neptunium(IV), uraniuM(IV), thorium(IV), neptunium(V), plutonium (VI), uranium (VI), lanthanum(III), cerium(III), europium(III), ytterbium(III), ytterium(III), strontium(II), barium(II), radium(II), cesium(I) with 3.2 M, 6.2 M, 9.3 M, and 12.2 M HCl solutions from Dowex-50 cation exchange resin columns. These elutions show that in high concentrations of hydrochloric acid the actinides form complex ions with chloride ion to a much greater extent than the lanthanides. The strengths of the tripositive actinide complex ions apparently go in the order plutonium > americium> curium, although their ionic radii also decrease in this same order. To explain these results, a partial covalent character may be ascribed to the bonding in the transuranium complex ions. It is shown that a reasonable structure for such covalent bonding involves hybridization of the 5f orbitals in the actinide elements.
Download or read book Vinyl Cations written by Peter Stang and published by Elsevier. This book was released on 2012-12-02 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vinyl Cations provides a comprehensive and detailed treatment of the reactive intermediate in which the electron-deficient carbon is an integral part of a ? unsaturation. This book emphasizes that the reaction through vinyl cations is a viable pathway among the multitude of mechanistic routes for vinylic substitution. The aryl, ethynyl, and allenyl cations from the viewpoint of direct solvolytic generation from appropriate allenyl precursors are briefly discussed. Other topics include the preparative aspects of electrophilic additions to alkynes, participation of allenyl bonds in solvolyses, and vinyl cations generated through diazonium ions. The nature of the cationic intermediates, migrations across the double bond, thiirenium ions, and species related to vinyl cations are likewise elaborated. This publication is beneficial to chemists and researchers concerned with vinyl cations.
Download or read book Supramolecular Chemistry in the 3rd Millennium written by Catherine E. Housecroft and published by MDPI. This book was released on 2021-08-18 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Special Issue is one of the first for the new MDPI flagship journal Chemistry (ISSN 2624-8549) which has a broad remit for publishing original research in all areas of chemistry. The theme of this issue is Supramolecular Chemistry in the 3rd Millennium and I am sure that this topic will attract many exciting contributions. We chose this topic because it encompasses the unity of contemporary pluridisciplinary science, in which organic, inorganic, physical and theoretical chemists work together with molecular biologists and physicists to develop a systems-level understanding of molecular interactions. The description of supramolecular chemistry as 'chemistry beyond the molecule' (Jean-Marie Lehn, Nobel Lecture and Gautam R. Desiraju, Nature, 2001, 412, 397) addresses the wide variety of weak, non-covalent interactions that are the basis for the assembly of supramolecular architectures, molecular receptors and molecular recognition, programed molecular systems, dynamic combinatorial libraries, coordination networks and functional supramolecular materials. We welcome submissions from all disciplines involved in this exciting and evolving area of science.
Download or read book Analytical Methods in Supramolecular Chemistry written by Christoph A. Schalley and published by John Wiley & Sons. This book was released on 2012-09-25 with total page 849 pages. Available in PDF, EPUB and Kindle. Book excerpt: The second edition of "Analytical Methods in Supramolecular Chemistry" comes in two volumes and covers a broad range of modern methods and techniques now used for investigating supramolecular systems, e. g. NMR spectroscopy, mass spectrometry, extraction methods, crystallography, single molecule spectroscopy, electrochemisty, and many more. In this second edition, tutorial inserts have been introduced, making the book also suitable as supplementary reading for courses on supramolecular chemistry. All chapters have been revised and updated and four new chapters have been added. A must-have handbook for Organic and Analytical Chemists, Spectroscopists, Materials Scientists, and Ph.D. Students in Chemistry. From reviews of the first edition: "This timely book should have its place in laboratories dealing with supramolecular objects. It will be a source of reference for graduate students and more experienced researchers and could induce new ideas on the use of techniques other than those usually used in the laboratory." Journal of the American Chemical Society (2008) VOL. 130, NO. 1 doi: 10.1021/ja0769649 "The book as a whole or single chapters will stimulate the reader to widen his horizon in chemistry and will help him to have new ideas in his research." Anal Bioanal Chem (2007) 389:2039-2040 DOI: 10.1007/s00216-007-1677-1
Download or read book Anion Receptor Chemistry written by Jonathan L Sessler and published by Royal Society of Chemistry. This book was released on 2007-10-31 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anion recognition plays a critical role in a range of biological processes, and a variety of receptors and carriers can be found throughout the natural world. Chemists working in the area of supramolecular chemistry have created a range of anion receptors, drawing inspiration from nature as well as their own inventive processes. This book traces the origins of anion recognition chemistry as a unique sub-field in supramolecular chemistry while illustrating the basic approaches currently being used to effect receptor design. The combination of biological overview and summary of current synthetic approaches provides a coverage that is both comprehensive and comprehensible. First, the authors detail the key design motifs that have been used to generate synthetic receptors and which are likely to provide the basis for further developments. They also highlight briefly some of the features that are present in naturally occurring anion recognition and transport systems and summarise the applications of anion recognition chemistry. Providing as it does a detailed review for practitioners in the field and a concise introduction to the topic for newcomers, Anion Receptor Chemistry reflects the current state of the art. Fully referenced and illustrated in colour, it is a welcome addition to the literature.
Download or read book Beauty in Chemistry written by Luigi Fabbrizzi and published by Springer Science & Business Media. This book was released on 2012-02-22 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Beauty of Chemistry in the Words of Writers and in the Hands of Scientists, by Margherita Venturi, Enrico Marchi und Vincenzo Balzani Living in a Cage Is a Restricted Privilege, by Luigi Fabbrizzi Inner and Outer Beauty, by Kenneth N. Raymond und Casey J. Brown The Mechanical Bond: A Work of Art, by Carson J. Bruns und J. Fraser Stoddart The Beauty of Knots at the Molecular Level, by Jean-Pierre Sauvage und David B. Amabilino
Download or read book Cage Metal Complexes written by Yan Voloshin and published by Springer. This book was released on 2017-05-11 with total page 475 pages. Available in PDF, EPUB and Kindle. Book excerpt: This fundamental book presents the most comprehensive summary of the current state in chemistry of cage metal complexes. After their previous book “The Encapsulation Phenomenon” (www.springer.com/978-3-319-27737-0) the authors in this book focus on the encapsulation of metal ions by different types of three-dimensional mono- and polynucleating caging ligands. Within these cage metal complexes, (metal) ions can be isolated from external factors. The book provides both a classification of the cage compounds and summaries of synthetic approaches. On that basis the authors then describe the unique chemical and physical properties and the resulting reactivity of the cage compounds, as well as practical and potential applications as potent topological drugs and prodrugs, antifibrillogenic agents, radiodiagnostic and radiotherapeutic compounds, paramagnetic probes, single-molecule magnets, electrocatalysts for hydrogen production, (photo)electronic devices, and many more. Readers will find a well-structured and concise overview, with particular emphasis on a review of synthesis and reactivity of various cage metal complexes, summarizing over 400 literature references, clearly presented in over 300 color schemes and figures.
Download or read book Molecular Devices and Machines written by Vincenzo Balzani and published by John Wiley & Sons. This book was released on 2006-03-06 with total page 511 pages. Available in PDF, EPUB and Kindle. Book excerpt: The miniaturization of bulky devices and machines is a process that confronts us on a daily basis. However, nanoscale machines with varied and novel characteristics may also result from the enlargement of extremely small building blocks, namely individual molecules. This bottom-up approach to nanotechnology is already being pursued in information technology, with many other branches about to follow. - Written by a team of experienced authors headed by Vincenzo Balzani, one of the pioneers in the development of molecular machines - Covers such diverse aspects as sensors, memory components, solar energy conversion, biomolecules as molecular machines, and much more - Presented in a lucid style and didactically structured, with both the expert and the newcomer in mind - Includes a glossary of terms and numerous references to the recent literature Be among the first to explore the fascinating possibilities of this future-oriented technology! A must-have for every chemist and materials scientist with an interest in nanotechnology.
Download or read book Data Mining in Crystallography written by D. W. M. Hofmann and published by Springer. This book was released on 2009-12-24 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: Humans have been “manually” extracting patterns from data for centuries, but the increasing volume of data in modern times has called for more automatic approaches. Early methods of identifying patterns in data include Bayes’ theorem (1700s) and Regression analysis (1800s). The proliferation, ubiquity and incre- ing power of computer technology has increased data collection and storage. As data sets have grown in size and complexity, direct hands-on data analysis has - creasingly been augmented with indirect, automatic data processing. Data mining has been developed as the tool for extracting hidden patterns from data, by using computing power and applying new techniques and methodologies for knowledge discovery. This has been aided by other discoveries in computer science, such as Neural networks, Clustering, Genetic algorithms (1950s), Decision trees (1960s) and Support vector machines (1980s). Data mining commonlyinvolves four classes of tasks: • Classi cation: Arranges the data into prede ned groups. For example, an e-mail program might attempt to classify an e-mail as legitimate or spam. Common algorithmsinclude Nearest neighbor,Naive Bayes classi er and Neural network. • Clustering: Is like classi cation but the groups are not prede ned, so the algorithm will try to group similar items together. • Regression: Attempts to nd a function which models the data with the least error. A common method is to use Genetic Programming. • Association rule learning: Searches for relationships between variables. For example, a supermarket might gather data of what each customer buys.
Download or read book Gold Chemistry written by Fabian Mohr and published by John Wiley & Sons. This book was released on 2009-04-20 with total page 425 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by world-class authors, this most recent major book on the topic highlights new and current trends as well as future directions. It is comprehensive in its scope, covering all aspects of gold chemistry -- from homogeneous to heterogeneous catalysis, from supramolecular assemblies to sensors and medicinal applications. The result is an invaluable work for both organic and inorganic chemists working in universities and industry, as well as material scientists.
Download or read book Dynamic Combinatorial Chemistry written by Joost N. H. Reek and published by John Wiley & Sons. This book was released on 2010-02-02 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: This long-awaited first book on this exciting new field in organic and supramolecular chemistry explains the fundamentals as well as possible applications of DCC. Authored by the "Who's Who" of DCC it spans the whole range of topics: catalysts, sensors, polymers, ligands, receptors, concluding with a look at future developments and perspectives. All set to become the standard text in the field, this one-stop reference contains everything organic, catalytic, polymer, physical and biochemists need to know.
Download or read book Macrocyclic Chemistry written by K. Gloe and published by Springer Science & Business Media. This book was released on 2005-12-05 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: Macrocyclic Chemistry: Current Trends and Future Perspectives illustrates essential concepts in this expanding research field covering both basic and applied studies. Written by well-known experts from around the world, the topics of the chapters range from new macrocyclic architectures with different functions and self-assembly processes through to the modeling and dynamics of such systems. The content also reflects on application possibilities in analytical chemistry, separation processes, material preparation and medicine. Thus this book serves as a creative source of research strategies and methodic tools. Providing an excellent overview of the field, this book will be a valuable resource for researchers in industry and academic institutions as well as for teachers of science and graduate students. This book is devoted to the long-standing tradition of the International Symposia on Macrocyclic Chemistry (ISMC) and published to coincide with the 30th meeting, Dresden, Germany.
