Author: Marco Taddei Publisher: MDPI ISBN: 3039280023 Category : Mathematics Languages : en Pages : 120
Book Description
The present Special Issue of Symmetry is devoted to two important areas of global Riemannian geometry, namely submanifold theory and the geometry of Lie groups and homogeneous spaces. Submanifold theory originated from the classical geometry of curves and surfaces. Homogeneous spaces are manifolds that admit a transitive Lie group action, historically related to F. Klein's Erlangen Program and S. Lie's idea to use continuous symmetries in studying differential equations. In this Special Issue, we provide a collection of papers that not only reflect some of the latest advancements in both areas, but also highlight relations between them and the use of common techniques. Applications to other areas of mathematics are also considered.
Author: Abraham Clearfield Publisher: Royal Society of Chemistry ISBN: 1849733570 Category : Science Languages : en Pages : 676
Book Description
Metal phosphonate chemistry is a highly interdisciplinary field, as it encompasses several other areas, such as materials chemistry, gas storage, pharmaceutics, corrosion control, classical chemical synthesis, X-Ray crystallography, powder diffraction, etc. It has also acquired additional significance due to "Metal-Organic Frameworks", as evidenced by the hundreds of papers published each year. Currently there is no other book on the topic and this book fills the gap in the literature by summarising in a concise way the latest developments in the field. Metal phosphonate chemistry has seen impressive growth in the last 15-20 years and there is a clear need to systematize and organize all this growth. This unique book accomplishes just that need - edited by two experts, it includes contributions from other experienced researchers and organises, cateqorises and presents in an attractive way the latest hot topics in metal phosphonate chemistry and related applications. With an extensive bibliography, it is a great reference for academic and industrial researchers as well as students working in the field and will act as a starting point for further exploration of the literature. It is also of great interest to scientists working in the broader area of metal-organic frameworks and their applications.
Author: Houston Phillipp Perry Publisher: ISBN: Category : Languages : en Pages :
Book Description
The primary goal of the work described in this dissertation was the incorporation of functionality into metal phosphonates. This was done in one of several ways. The first involved using phosphonate ligands that had covalently attached organic functional groups. In some cases, these ligands undergo reactions during the solvothermal syntheses which can impart new chemical reactivity. Another method used to introduce functionality was to partially or completely substitute metal atoms within phosphonate clusters to create materials which may have interesting magnetic properties. By controlling the way these clusters pack in the solids, their magnetic properties may be able to be augmented. The final method used to impart functionality to metal phosphonates was the incorporation of N-donor and bulky aryl groups into the phosphonate ligands. These influences caused structural variations which exposed potentially active sites within the materials, including both Lewis acidic and basic sites, as well as Bronsted acid sites. The first strategy was employed in the design of tetravalent metal phosphonates which have covalently incorporated bipyridine moieties. The materials are porous so that the bipyridine sites can chelate Pd atoms from solution, which can then be reduced to stable nanoparticles trapped within the phosphonate matrix. This approach was also used in the synthesis of surface-functionalized divalent metal phosphonates which exhibit interesting amine uptake properties. Solvent and cation substitution effects were used to control the packing and connectivity of phosphonate-based clusters. The selective substitution of metal atoms within the clusters may lead to interesting magnetic materials. In other work, N-donor and bulky phosphonates were used to influence the structure of several SnII phosphonates, which resulted in the discovery of a new layered structure type. The effect of the Sn-N interaction on the structures is investigated, and found to have significant effects on the structural units formed and how they pack in the solid state. The work presented herein represents only a small fraction of the rich chemistry of metal phosphonates. Creative researchers will continue to push boundaries and find new and interesting applications for phosphonate-based materials.
Author: Ram K. Gupta Publisher: Springer Nature ISBN: 3031270622 Category : Science Languages : en Pages : 401
Book Description
This book provides fundamental electrochemical behavior and understanding of devices based on Metal Phosphates and Phosphonates. The basic concepts, properties and emerging applications of these materials as batteries, supercapacitors, fuel cells, sensors, biomedical and environmental are covered. Apart from conventional techniques, this book explores new aspects of synthesizing Metal Phosphates and Phosphonates.
Author: Tiffany L. Kinnibrugh Publisher: ISBN: Category : Languages : en Pages :
Book Description
This dissertation focuses on the challenge of developing porous metal arylphosphonates with both high crystallinity and functional porosity by using different synthetic approaches. Metal phosphonates are an extensive class of materials based upon extended inorganic-organic architectures such as chains, layers and three-dimensional networks. Metal phosphonates generally favor extended inorganic architectures leading to pillared materials with no porosity. We found that the use of template molecules, type of ligand and choice of metal ions could be used to deviate from the pillared structure. Many of these structures had interesting properties that were explored. The results can be divided into three areas: We developed non-pillared monovalent metal phosphonates by investigating both the role of water and template molecules in the solvothermal synthesis. The role of water in solvothermal reactions was found to have a profound influence on the structure of monovalent metal phosphonates and the structures could be tailored from zero/one-dimensional to two-dimensional. Non-pillared structures could be synthesized by using template molecules. For a zinc phosphonate, we converted a layered structure into a three-dimensional framework by using small template molecules in the solvothermal reaction. The compound exhibited reversible dehydration behavior. The change in the framework structure and guest positions was monitored during this process. Two different ligands were used in the development of porous aluminum phosphonates. One series exhibited reversible dehydration behavior, which had a dramatic influence on permanent porosity of the material. The stability of the dehydrated phase is a result of the geometry of the aluminum atom, which in some cases has coordinatively unsaturated metal sites. The second series was developed with ion exchange applications in mind therefore the pore environment was tailored to favor ion exchange processes. The most important aspect is that these compounds exhibit high selectivity for Th4+ ions. In total 28 new compounds were prepared, and their utility and structures clarified. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151103
Author: Kevin James Gagnon Publisher: ISBN: Category : Languages : en Pages :
Book Description
The goal of the work described in this dissertation was to investigate the structure of metal phosphonate frameworks which were composed of conformationally flexible ligands. This goal was achieved through investigating new syn-thetic techniques, systematically changing structural aspects (i.e. chain length), and conducting in situ X-ray diffraction experiments under non-ambient conditions. First, the use of ionic liquids in the synthesis of metal phosphonates was investigated. Reaction systems which had previously been studied in purely aqueous synthetic media were reinvestigated with the addition of a hydrophobic ionic liquid to the reaction. Second, the structural diversity of zinc alkylbisphosphonates was investigated through systematically varying the chain length and reaction conditions. Last, the structural changes associated with externally applied stimuli (namely temperature and pressure) on conformationally flexible metal phosphonates were investigated. Elevated temperature was used to investigate the structur-al changes of a 1-D cobalt chain compound through three stages of dehydration and also applied pressures of up to 10 GPa were used to probe the structural resilience of two zinc alkylbisphosphonate materials under. The iminobis(methylphosphonic acid) type ligands are a good example of a small, simple, conformationally flexible ligand. There are three distinct different structural types, utilizing this ligand with cobalt metal, described in the literature, all of which contain bound or solvated water molecules. The addition of a hydrophobic ionic liquid to an aqueous synthesis medium resulted in new anhydrous compounds with unique structural features. Systematic investigations of zinc alkylbisphosphonate materials, constructed with three to six carbon linker ligands, resulted in four new families of compounds. Each of these families has unique structural features which may prove interesting in future applications developments. Importantly, it is shown that whether the chain length is odd or even plays a role in structural type although it is not necessarily a requirement for a given structural type; furthermore, chain length itself is not strictly determinative of structural type. Dehydration in a cobalt phosphonate was followed via in situ single crystal X-ray diffraction. The compound goes through a two-stage dehydration mecha-nism in which the compound changes from a 1-D chain to a 2-D sheet. This pro-cess is reversible and shows unique switchable magnetic properties. The high pressure studies of an alkyl chain built zinc metal phosphonate showed that the chains provide a spring-like cushion to stabilize the compression of the system allowing for large distortions in the metal coordination environment, without destruction of the material. This intriguing observation raises questions as to whether or not these types of materials may play a role as a new class of piezo-functional solid-state materials. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151137
Author: Sasikumar Palani Publisher: LAP Lambert Academic Publishing ISBN: 9783659764547 Category : Languages : en Pages : 300
Book Description
This book chapters deals with synthetic development of new phosphonic acids and phosphate ligands. Interaction of these phosphorus based ligands with various main group-, transition metal ions and organotin precursors. The metal aggregates thus prepared were structurally and spectroscopically characterized. These aggregates were shown to be good single molecular precursors for material purpose. Ceriumphosphonate were utilized as catalyst for prepare pharmaceutically valuable functionalized dihydropyrimidines (three-component Biginelli reaction). All the di-nuclear metal aggregates were found to be artificial nucleases.
Author: Ali Morsali Publisher: John Wiley & Sons ISBN: 1119640431 Category : Science Languages : en Pages : 256
Book Description
Owing to the extensive interest in construction of functional metal organic frameworks (FMOFs), this book discusses the roles of functional groups on the structure and application of metal organic frameworks (MOFs). The contents of the book are classified based on the structural and chemical properties of organic functions, in order to make readers able to compare the different effects of each function on the structure and application of the MOFs. In each chapter, the chemical properties of applied functional groups are gathered to give deeper insight into the roles of organic functions in the structure and application of MOFs. In the function-application properties, the authors discuss how a functional group can dominate the host-guest chemistry of the MOFs and how this host-guest chemistry can expand the effectiveness and efficiency of the material in different fields of applications. Finally, function-structure properties are discussed. In function-application properties, it is discussed how a functional group can affect the topology, porosity, flexibility and stability of the framework. The features of this subject are novel and are presented for the first time.
Author: Marco Taddei
Author: Abraham Clearfield
Author: Houston Phillipp Perry
Author: Ram K. Gupta
Author: Mark R. Torgerson
Author: Tiffany L. Kinnibrugh
Author: Ferdinando Costantino
Author: Kevin James Gagnon
Author: Sasikumar Palani
Author: Ali Morsali