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 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 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 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 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 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 Macromolecular Metal Carboxylates and Their Nanocomposites written by Anatolii D. Pomogailo and published by Springer Science & Business Media. This book was released on 2010-09-02 with total page 311 pages. Available in PDF, EPUB and Kindle. Book excerpt: Data on the synthesis and physicochemical studies of salts of mono- or dibasic unsaturated carboxylic acids and macromolecular metal carboxylates are generalised and described systematically in this monograph. The structures and properties of the COO group in various compounds and characteristic features of the structures of carboxylate are analysed. The main routes and kinetics of polymerisation transformations of unsaturated metal carboxylates are considered. The attention is focused on the effect of the metal ion on the monomer reactivity and the polymer morphology and structure. The possibility of stereochemical control of radical polymerisation of unsaturated metal carboxylates is demonstrated. The electronic, magnetic, optical, absorption and thermal properties of metal (co)polymers and nanocomposites and their main applications are also considered.
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 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 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 Metallo Supramolecular Polymers written by Masayoshi Higuchi and published by Springer Nature. This book was released on 2019-11-12 with total page 92 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 Dynamic Covalent Chemistry written by Wei Zhang and published by John Wiley & Sons. This book was released on 2017-11-29 with total page 471 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first and only exhaustive review of the theory, thermodynamic fundamentals, mechanisms, and design principles of dynamic covalent systems Dynamic Covalent Chemistry: Principles, Reactions, and Applications presents a comprehensive review of the theory, thermodynamic fundamentals, mechanisms, and design principles of dynamic covalent systems. It features contributions from a team of international scientists, grouped into three main sections covering the principles of dynamic covalent chemistry, types of dynamic covalent chemical reactions, and the latest applications of dynamic covalent chemistry (DCvC) across an array of fields. The past decade has seen tremendous progress in (DCvC) research and industrial applications. The great synthetic power and reversible nature of this chemistry has enabled the development of a variety of functional molecular systems and materials for a broad range of applications in organic synthesis, materials development, nanotechnology, drug discovery, and biotechnology. Yet, until now, there have been no authoritative references devoted exclusively to this powerful synthetic tool, its current applications, and the most promising directions for future development. Dynamic Covalent Chemistry: Principles, Reactions, and Applications fills the yawning gap in the world literature with comprehensive coverage of: The energy landscape, the importance of reversibility, enthalpy vs. entropy, and reaction kinetics Single-type, multi-type, and non-covalent reactions, with a focus on the advantages and disadvantages of each reaction type Dynamic covalent assembly of discrete molecular architectures, responsive polymer synthesis, and drug discovery Important emerging applications of dynamic covalent chemistry in nanotechnology, including both material- and bio-oriented directions Real-world examples describing a wide range of industrial applications for organic synthesis, functional materials development, nanotechnology, drug delivery and more Dynamic Covalent Chemistry: Principles, Reactions, and Applications is must-reading for researchers and chemists working in dynamic covalent chemistry and supramolecular chemistry. It will also be of value to academic researchers and advanced students interested in applying the principles of (DCvC) in organic synthesis, functional materials development, nanotechnology, drug discovery, and chemical biology.
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.
Download or read book Silicon Containing Dendritic Polymers written by Petar R. Dvornic and published by Springer Science & Business Media. This book was released on 2009-01-09 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the last two decades silicon-containing dendritic polymers have become one of the fastest growing areas of development in polymer science. The eruption of interest in these new polymers stems from their unprecedented molecular architecture, unique resulting properties and the realization that they represent ideal building blocks for chemical nanotechnology. This is the first book to solely focus on silicon-containing dendritic polymers. The contributions of those experts who originally introduced each field or played a major role in its progress are reported. The developments in all major areas of this field are presented from their origins to the present. It is anticipated that this text will become an invaluable guide and vanguard of reference for experienced scientists interested in the fields of polymer and material science, synthetic chemistry, and nanotechnology. It will also serve advanced graduate students either as a source of creative inspiration or as a textbook for appropriate courses.
Download or read book Recent Development in Clusters of Rare Earths and Actinides Chemistry and Materials written by Zhiping Zheng and published by Springer. This book was released on 2016-10-21 with total page 343 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemical structure and bonding. The scope of the series spans the entire Periodic Table and addresses structure and bonding issues associated with all of the elements. It also focuses attention on new and developing areas of modern structural and theoretical chemistry such as nanostructures, molecular electronics, designed molecular solids, surfaces, metal clusters and supramolecular structures. Physical and spectroscopic techniques used to determine, examine and model structures fall within the purview of Structure and Bonding to the extent that the focus is on the scientific results obtained and not on specialist information concerning the techniques themselves. Issues associated with the development of bonding models and generalizations that illuminate the reactivity pathways and rates of chemical processes are also relevant. The individual volumes in the series are thematic. The goal of each volume is to give the reader, whether at a university or in industry, a comprehensive overview of an area where new insights are emerging that are of interest to a larger scientific audience.
Download or read book Supramolecular Chemistry written by Vincenzo Balzani and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 465 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first NATO Science Forum was held in Biarritz in September 1990. This Taormina Conference is the second in a series that we wish to be a long one and I believe that it has equalled the success of its predecessor. In setting up these meetings the NATO Science Committee wanted to gather leading experts to review fields of strong present interest. It was intended that presentations and discussions should pay special attention to potential developments. This "forward look" is indeed precious to us in mapping out the evolution of our Science Programme but more importantly, it is an essential part of the progress of Science. I believe that NATO, being able to bring together eminent scientists from both sides of the Atlantic, is in a priviliged position to provide this service to our Scientific Community. It was only proper that Chemistry should be one of the first areas to be targeted: a central science with many rich borders touching on other disciplines, it deserved the full attention of our Committee. In its vast domain, among many possible topics, the present one was carefully selected and its choice resulted from an extensive consultation of many leading chemists. The large fraction of replies which pointed to Supramolecular Chemistry left us with little doubt about the timeliness of a Forum in this area and the strong interest attached to it.
Download or read book Fullerenes written by Andreas Hirsch and published by John Wiley & Sons. This book was released on 2006-03-06 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this handbook, the leading experts in the field presents important and fundamental aspects of the organic and organometallic chemistry of fullerenes. Naturally they also cover the applications in material and medicinal science for these fascinating molecules. Completely self-contained, the book is logically arranged such that information is easy to retrieve, and the style lends itself to effortless reading and to learning more about the chemical properties of this family of molecules. A definitive "must" for everyone working in this ever-expanding sphere.
