При исследовании аллильных, бензильных и пиридильных производных моно-, дисилана и дисилоксана методами: УФ-, флуоресцентной, ИК-, рама- новской, 1H-, 13С- и 29Si-ЯМР-спектроскопии - установлено наличие внутримоле- кулярного донорно-акцепторного взаимодействия, реализующегося непосред- ственно через пространство по механизму (p-d)p,s-гомосопряжения между ва- кантными 3d-орбиталями атома кремния и заселенными граничными орбиталя- ми p- или n-электронодонорного центра, находящегося в молекуле в b-по- ложении относительно кремния. При этом показано, что в фенильных и бен- зильных дисилоксановых производных существенный вклад в делокализацию электронной плотности вносит (d-d)-гомосопряжение между атомами кремния. Кроме того, впервые обнаружено, что кремнийорганические дианионы могут обладать термически достижимым парамагнитным состоянием. На основе анализа своих и литературных экспериментальных данных и обобщения соответствующих выводов, в развитие теоретической элементоорга- нической химии сформулирована гипотеза, согласно которой (p-d)p,s- и (d-d)-го- мосопряжение является одним из основных механизмов “неклассической” дело- кализации электронной плотности в нейтральных элементоорганических соеди- нениях, в ряде случаев более важным, чем (p-d)p- и (d-d)-сопряжение, а также “прямое” и “обратное” сверхсопряжение. В совокупности с последними или самостоятельно (p-d)p,s- и/или (d-d)-гомосопряжение на основе областей класси- ческого p-сопряжения и/или неподеленных электронных пар может привести к образованию в молекуле единой зоны “квазисопряжения”. С позиций развивае- мых представлений дана интерпретация рассматриваемых экспериментальных данных, в том числе, низкой энергии первого триплетного уровня кремнийорга- нических дианионов. Кроме того, предсказано существование нового класса жестко-гибких полимерных систем - полигомосопряженных элементоорганиче- ских полимеров, характеризующихся наличием зон расширенного квазисопря- жения, решающий вклад в образование которых вносит (p-d)p,s- и (d-d)-гомосо- пряжение. УФ-спектры первого целенаправленно синтезированного полимера с заранее заданной структурой полигомосопряженного полимера - поли(диметил- силил-п-ксилилиден)а - подтверждают наличие в нем предсказываемых зон расширенного квазисопряжения.

Surface tension between water and air is caused by the attraction forces acting on the molecules of the liquid. A contact angle is the angle between the edge of the meniscus and the sold material, hydrophilic for hydrophobic.

The first book to cover conceptual quantum chemistry, Atomic Charges, Bond Properties, and Molecular Energies deftly explores chemical bonds, their intrinsic energies, and the corresponding dissociation energies, which are relevant in reactivity problems. This unique first-hand, self-contained presentation develops relatively uncomplicated but physically meaningful approaches to molecular properties by providing derivations of all the required formulas from scratch, developed in Professor Fliszar's laboratory. This book is vitally relevant to organic- and biochemists, molecular biologists, materials scientists, and nanoscientists.

This pioneering text provides not only a guideline for developing synthetic strategies for creating block copolymers with defined characteristics, but also a key to the relationship between the physical properties...and the structure and dynamics of materials.

Vol. 1 : Hydrolysis,Oxidation and Reduction. - 225 p.

This book describes 180 chemical compounds, some familiar to almost everyone, and some less commonly known. Each description includes some basic chemical and physical information about the compound, such as its chemical formula, other names by which the compound is known, and the molecular weight, melting point, freezing point, and solubility of the compound.

This volume is based on the National Academy of Sciences' colloquium entitled "Chemical Ecology: The Chemistry of Biotic Interaction." The articles appearing in these pages were contributed by speakers at the colloquium. Any opinions, findings, conclusions, or recommendations expressed in this volume are those of the authors and do not necessarily reflect the views of the National Academy of Sciences.

Vol. 1 : A-C. - 1419 p.

Written at a level accessible to nonspecialists, including high-school students, college students in introductory courses, and the general public, this encyclopedia's purpose is to assist users in acquiring knowledge and understanding of chemistry. The 509 alphabetically arranged, signed articles were written by subject specialists and range from concise definitions to multiple-page overviews. Broad areas covered include analytical chemistry applications, biochemistry, biographies, elements, energy, environmental chemistry, medicine, organic chemistry, physical chemistry, reactions, states of matter, and structure. Examples of specific article titles are Alchemy; Artificial sweeteners; Boron; Clones; Franklin, Rosalind; Isomerism; Mole concept; Nanochemistry; Rubber; Spectroscopy; and zwitterions. In addition to explaining scientific principles, this set relates chemistry to everyday life. For example, Silly Putty (a silicone-based material) is a "liquid solid," the color of hydrangeas is determined by soil acidity, and endorphins may allow marathoners' bodies to endure long races. An 18-page glossary and 67-page subject index are included in each volume. Glossary definitions also appear in the margins next to the text. Although there are some cross-references in the articles, the index is more thorough. About 300 black-and-white illustrations and diagrams clarify the concepts under discussion. There are no color illustrations; color would have been useful to elucidate concepts such as bonding and molecular structure. Bibliographic references and related Internet resources are listed at the end of many articles. A "For Your Reference" section at the beginning of each volume provides selected metric conversions, an alphabetic table of the elements; common abbreviations, symbols and acronyms, and a periodic table of the elements. The similar four-volume Macmillan Encyclopedia of Chemistry (1997), also edited by Lagowski, is aimed at a more academic audience and provides additional coverage of some topics. Although Chemistry: Foundations and Applications could be improved with the inclusion of some color illustrations, the very impressive scholarly contributors make this set worthy of consideration, particularly for high-school, large public, and undergraduate libraries. Nancy Cannon Copyright © American Library Association. All rights reserved

Chemistry: An Introduction for Medical and Health Sciences provides students and practitioners with a clear, readable introduction to the chemical terms and concepts that are relevant to their study and practice. Assuming little prior knowledge of the subject the book describes and explains the chemistry underlying many of the most commonly prescribed drugs and medicines. It also includes information on chemical aspects of digestion and nutrition, oxidation, radioactivity and an overview of how chemicals fight disease.

This Third Edition of Glassman's classic text clearly defines the role of chemistry, physics, and fluid mechanics as applied to the complex topic of combustion. Glassman's insightful introductory text emphasizes underlying physical and chemical principles, and encompasses engine technology, fire safety, materials synthesis, detonation phenomena, hydrocarbon fuel oxidation mechanisms, and environmental considerations. Combustion has been rewritten to integrate the text, figures, and appendixes, detailing available combustion codes, making it not only an excellent introductory text but also an important reference source for professionals in the field.

Vol. 2 : ADDITIONS TO C-X П-BONDS, PART 2 . - 1233 p.

Examines computer modeling of enzyme reactions (including enzyme kinetics), techniques popular in the fields of physical, organic, and biochemistry as well as pharmaceutical research. Includes practical computer exercises and sample computer programs which can be run on a PC. The programs serve as simple illustrations of the different concepts of computer modeling and as an introduction to more versatile computer modeling packages which can be run on mainframes. Also provides an introduction to the rapidly growing field of computer simulation and modeling of macromolecules, emphasizing structure-function correlation in proteins and the action of enzymes.

Until now, the literature has offered a rather limited approach to the use of fundamental kinetics and their application to catalytic reactions. Subsequently, this book spans the full range from fundamentals of kinetics and heterogeneous catalysis via modern experimental and theoretical results of model studies to their equivalent large-scale industrial production proce... more »sses. This second edition includes significant new developments, with all the chapters updated by way of recent examples and relevant new literature. With its focus on practical application, rather than theory, the result is key knowledge for students at technical universities and professionals already working in industry.

Emphasizing the potential and impact of the burgeoning nanotechnology field, this six-volume encyclopedia set discusses the fundamental principles, theories, and methodologies that impact nanosystem design innovations in nanostructured materials, nanodevices, and system architectures. Unparalleled in scope and depth, it examines the properties, performance, and engineering of materials that have controllable features on the nanometer scale; new simulation tools and computational methods; and the construction, integration, and application of tools for the measurement and imaging of biological materials.

To render the surface of ultrafiltration membranes biocidal, cellulose membranes were modified with chitosan, a naturally occurring polycationic biocide. Through the use of chitosans of different molecular weights and membranes with different pore sizes, the alteration of the morphological structure of tethered chitosan layers was achieved. The importance of such structural differences in the antimicrobial activity of the prepared membranes against gram-positive Staphylococcus aureus and gram-negative Escherichia coli was studied. The antimicrobial efficiency improved with the use of chitosans with higher molecular weights and membranes with smaller pore sizes. This suggested that the surface location of the grafted chitosan chains was more preferential for a higher antimicrobial activity of the surface. Membranes modified with chitosan showed higher antimicrobial efficiency against gram-positive S. aureus than against gramnegative E. coli.

Der Anfänger findet hier eine ausführliche Einführung in den Umgang mit den Laborgeräten des organisch-chemischen Praktikums. Außerdem werden nützliche Informationen z.B. zur Herstellung von Lösungen bestimmter Konzentrationen oder zum Reinigen und Trocknen von Lösungsmitteln angeboten.