Author: Lisa Kirchner Publisher: ISBN: Category : Crystal growth Languages : en Pages : 202
Book Description
This research was to design and successfully engineer crystals using the non-covalent halogen bonding interaction. A halogen bond is an attractive interaction between a positive electrostatic potential on a halogen atom and a negative site on another molecule. Halogen bonds are increasingly recognized as an effective force for the self-assembly of molecules in predictable patterns to produce new materials with certain desirable properties. The research focused on the formation of large planar polyaromatic assemblies of molecules containing halogen bond donor and acceptor sites. The planar polyaromatic compounds were synthesized using multiple Sonogashira Coupling reactions. This is a cross-coupling reaction that forms carbon-carbon bonds between a terminal alkyne and an aryl halide using palladium catalysts. The X-ray crystal structures of the series of iodo- and bromo-phenylethynylphenylethynylpyridines were shown to form self-complementary dimers in the solid state. The perfluoroiodo- and perfluorobromophenylethynylphenylethynyl derivatives, 3-[{4-[(2-bromo-3, 4, 5, 6- tetrafluorophenyl)ethynyl]phenyl}ethynyl]pyridine, 3-[{4-[(2, 3, 4, 5-tetrafluoro-6-iodophenyl)ethynyl]phenyl}ethynyl]pyridine and 2-[{4-[(3-bromo-2, 4, 5, 6-tetrafluoro- phenyl)ethynyl]phenyl}ethynyl]pyridine, formed self-complementary halogen-bonded dimeric units in the solid state. In contrast, 3-[{4-[(2-bromo-4, 5-difluorophenyl)ethynyl]phenyl}ethynyl]pyridine formed a C-H···N hydrogen- bonded dimer.
Author: Stefan Huber Publisher: John Wiley & Sons ISBN: 3527347313 Category : Technology & Engineering Languages : en Pages : 418
Book Description
Long-awaited on the importance of halogen bonding in solution, demonstrating the specific advantages in various fields - from synthesis and catalysis to biochemistry and electrochemistry! Halogen bonding (XB) describes the interaction between an electron donor and the electrophilic region of a halogen atom. Its applicability for molecular recognition processes long remained unappreciated and has mostly been studied in solid state until recently. As most physiological processes and chemical reactions take place in solution, investigations in solutions are of highest relevance for its use in organic synthesis and catalysis, pharmaceutical chemistry and drug design, electrochemistry, as well as material synthesis. Halogen Bonding in Solution gives a concise overview of halogen bond interactions in solution. It discusses the history and electronic origin of halogen bonding and summarizes all relevant examples of its application in organocatalysis. It describes the use of molecular iodine in catalysis and industrial applications, as well as recent developments in anion transport and binding. Hot topic: Halogen bonding is an important interaction between molecules or within a molecule. The field has developed considerably in recent years, with numerous different approaches and applications having been published. Unique: There are several books on halogen bonding in solid state available, but this will be the first one focused on halogen bonding in solution. Multi-disciplinary: Summarizes the history and nature of halogen bonding in solution as well as applications in catalysis, anion recognition, biochemistry, and electrochemistry. Aimed at facilitating exciting future developments in the field, Halogen Bonding in Solution is a valuable source of information for researchers and professionals working in the field of supramolecular chemistry, catalysis, biochemistry, drug design, and electrochemistry.
Author: Chamara Abeywickramasinghe Gunawardana Publisher: ISBN: Category : Languages : en Pages :
Book Description
A set of multifunctional molecules [isomeric forms of 1-(pyridylmethyl)-2,2'-biimidazole] was synthesized and subjected to systematic co-crystallizations with selected hydrogen- and halogen-bond donors in order to explore the impact of interaction type, geometry and electrostatics on the resulting supramolecular architectures. The structural outcome with hydrogen-bond donors (carboxylic acids) is somewhat unpredictable because of the presence of the acid···biimidazole heterosynthon that can compete with biimidazole···biimidazole homosynthon. In contrast, the solid-state supramolecular behavior of those probe molecules is largely unchanged in halogen-bonded co-crystals. Only two types of primary interactions, the two-point hydrogen bonds responsible for pairing biimidazole moieties, and the single-point halogen bonds responsible for the co-crystal formation and structure extension, are present in these systems. The results highlight that, by incorporating geometric biases along with orthogonal interactions, one can effectively prevent synthon crossover which is of paramount importance in complex crystal engineering endeavors. Heterobifunctional ligands pave the way for elaborate metallo-supramolecular systems, and are also useful for combining metal-ligand bonding with other types of non-covalent interactions. Nine new acetylacetonate ligands featuring either pyridyl- or thiophenyl-heterocycles were successfully prepared, and their metal binding abilities were studied with selected di- and tri-valent transition metal ions. As expected, the acetylacetonate ligation to metal dications remains consistent. In each case, the metal is four-coordinate and resides in a square planar environment. Differences in the overall architectures arise from the role played by the terminal heterocycles and the solvent. In seven (out of nine) structures, the heterocyclic end is involved in a structure-directing interaction and it is more prevalent in ligands bearing 4-pyridinyl unit. Divergent molecules containing bulky substituents tend to produce porous materials via frustrated packing. Two rigid tetrahedral cores, tetraphenylmethane and 1,3,5,7-tetraphenyladamantane, grafted peripherally with four (trimethylsilyl)ethynyl moieties were found to have only isolated voids in their crystal structures. Hence, they were modified into tecton-like entities, tetrakis(4-(iodoethynyl)phenyl)methane [I4TEPM] and 1,3,5,7-tetrakis(4-(iodoethynyl)phenyl)adamantane [I4TEPA], and the effect of motif-forming characteristics of iodoethynyl units on molecular arrangement and crystal porosity was analyzed. I4TEPM not only holds increased free volume compared to its precursor, but also forms one-dimensional channels. Furthermore, it readily co-crystallizes with Lewis basic solvents to afford two-component porous materials even though they suffer from stability issues. As the binding sites in I4TEPM and I4TEPA are tetrahedrally-predisposed, they can be further utilized for the modular assembly of highly symmetric, three-dimensional extended architectures. With that in mind, these two building blocks were subsequently allowed to react with various halide salts, and it was found that the reactions between I4TEPM and tetraphenylphosphonium halides readily yield four-fold interpenetrated diamondoid networks sustained by C-I⋯X− (X− = chloride, bromide, iodide) halogen-bonding interactions. The halide anions exhibit mutual-induced fitting of their coordination and act as four-connecting tetrahedral nodes, while the tetraphenylphosphonium cations render essential templating information and structural support.
Author: Juan J Novoa Publisher: Royal Society of Chemistry ISBN: 1788013336 Category : Science Languages : en Pages : 782
Book Description
The field of crystal engineering concerns the design and synthesis of molecular crystals with desired properties. This requires an in-depth understanding of the intermolecular interactions within crystal structures. This new book brings together the latest information and theories about intermolecular bonding, providing an introductory text for graduates. The book is divided into three parts. The first part covers the nature, physical meaning and methods for identification and analysis of intermolecular bonds. The second part explains the different types of bond known to occur in molecular crystals, with each chapter written by a specialist in that specific bond type. The final part discusses the cooperativity effects of different bond types present in one solid. This comprehensive textbook will provide a valuable resource for all students and researchers in the field of crystallography, materials science and supramolecular chemistry.
Author: A Kitaigorodsky Publisher: Elsevier ISBN: 0323145655 Category : Science Languages : en Pages : 571
Book Description
Molecular Crystals and Molecules deals with some of the problems of molecular crystallography and certain aspects of molecular structure. This book is composed of eight chapters that specifically cover the significant progress of conformational research. The opening chapter describes the structure of crystals considering the close-packing principle, disorder elements, and binary systems. The next two chapters examine the calculation of crystal lattice energy and dynamics. These topics are followed by discussions on the molecular movement, structural, and thermodynamic aspects of crystals. The final chapters look into the parameters for conformational calculations of molecules, macromolecules, and biopolymers. This book will be of great value to physical chemists and researchers who are interested in crystal and molecular structure.
Author: Tatsuo Kaiho Publisher: John Wiley & Sons ISBN: 1118878655 Category : Science Languages : en Pages : 668
Book Description
This book comprehensively covers iodine, its chemistry, and its role in functional materials, reagents, and compounds. • Provides an up-to-date, detailed overview of iodine chemistry with discussion on elemental aspects: characteristics, properties, iodides, and halogen bonding • Acts as a useful guide for readers to learn how to synthesize complex compounds using iodine reagents or intermediates • Describes traditional and modern processing techniques, such as starch, cupper, blowing out, and ion exchange resin methods • Includes seven detailed sections devoted to the applications of iodine: Characteristics, Production, Synthesis, Biological Applications, Industrial Applications, Bioorganic Chemistry and Environmental Chemistry, and Radioisotopes • Features hot topics in the field, such as hypervalent iodine-mediated cross coupling reactions, agrochemicals, dye sensitized solar cells, and therapeutic agents
Author: Pierangelo Metrangolo Publisher: Springer ISBN: 3540743308 Category : Science Languages : en Pages : 230
Book Description
This series presents critical reviews of the present position and future trends in modern chemical research concerned with chemical structure and bonding. It contains short and concise reports, each written by the world's renowned experts. The series is still valid and useful after five or ten years. More information is available at springerlink.com along with the electronic version of the whole content.
Author: Lisa Kirchner
Author: Pierangelo Metrangolo
Author: Xin Ding
Author: Stefan Huber
Author: Rosa Daneen Bailey Walsh
Author: Chamara Abeywickramasinghe Gunawardana
Author: Juan J Novoa
Author: A Kitaigorodsky
Author: Tatsuo Kaiho
Author: Pierangelo Metrangolo