Attempted Identification Of 13 Biradicals By Flash Photolysis And Pulse Radiolysis

Chemical Kinetics bridges the gap between beginner and specialist with a path that leads the reader from the phenomenological approach to the rates of chemical reactions to the state-of-the-art calculation of the rate constants of the most prevalent reactions: atom transfers, catalysis, proton transfers, substitution reactions, energy transfers and electron transfers. For the beginner provides the basics: the simplest concepts, the fundamental experiments, and the underlying theories. For the specialist shows where sophisticated experimental and theoretical methods combine to offer a panorama of time-dependent molecular phenomena connected by a new rational. Chemical Kinetics goes far beyond the qualitative description: with the guidance of theory, the path becomes a reaction path that can actually be inspected and calculated. But Chemical Kinetics is more about structure and reactivity than numbers and calculations. A great emphasis in the clarity of the concepts is achieved by illustrating all the theories and mechanisms with recent examples, some of them described with sufficient detail and simplicity to be used in general chemistry and lab courses. * Looking at atoms and molecules, and how molecular structures change with time. * Providing practical examples and detailed theoretical calculations* Of special interest to Industrial Chemistry and Biochemistry

The development of mechanistic organic chemistry is filled with claims of short-lived reactive intermediates connecting starting material to product. In many ways this book represents a personal odyssey of the editor in this area of chemistry. I well remember my introduction to organic chemistry as an undergraduate working in the laboratories of Shelton Bank at SUNY Albany in the early 1970s, and the excitement and frustration attending the piecing together of the details of a reaction mechanism by working backwards from the stable products of the reaction. In those days the reaction and the reactive intermediates flew by too rapidly to permit direct observation. Thus it came as something of a revelation to me as a graduate student at Yale that it was possible to slow down a reaction and actually "see" such ephemeral species as carbenes and biradicals by spectroscopic methods, by generating them photochemically at cryogenic temperatures. In this monograph several chap ters are devoted to low-temperature studies. Dougherty has described the matrix EPR spectra of biradicals, which were pure conjecture only ten years ago. Michl and Arnold have described the matrix spectroscopy of cyciobutadiene, a molecule that has fascinated organic chemists for over a hundred years. They have shown that by using a combination of matrix spec troscopic methods it is possible to learn nearly as much about the structure of cyciobutadiene, the prototypical antiaromatic biradicaloid, as about that of a common shelf-stable reagent.

Applications of EPR in Radiation Research is a multi-author contributed volume presented in eight themes: I. Elementary radiation processes (in situ and low temperature radiolysis, quantum solids); II: Solid state radiation chemistry (crystalline, amorphous and heterogeneous systems); III: Biochemistry, biophysics and biology applications (radicals in biomaterials, spin trapping, free-radical-induced DNA damage); IV: Materials science (polymeric and electronic materials, materials for treatment of nuclear waste, irradiated food); V: Radiation metrology (EPR-dosimetry, retrospective and medical applications); VI: Geological dating; VII: Advanced techniques (PELDOR, ESE and ENDOR spectroscopy, matrix isolation); VIII: Theoretical tools (density-functional calculations, spectrum simulations).

The critically acclaimed laboratory standard for more than forty years, Methods in Enzymology is one of the most highly respected publications in the field of biochemistry. Since 1955, each volume has been eagerly awaited, frequently consulted, and praised by researchers and reviewers alike. More than 285 volumes have been published (all of them still in print) and much of the material is relevant even today--truly an essential publication for researchers in all fields of life sciences.

Plants produce chemicals as part of their normal metabolic activities. These include primary metabolites found in all plants, such as sugars and fats, as well as secondary metabolites, which can have therapeutic effects in humans and be refined to produce drugs. Plants synthesize a bewildering variety of phytochemicals, but most are derivatives of a few biochemical motifs. Numerous herbal-derived substances have been evaluated for their therapeutic potential. These include alkaloids, coumarins, saponins, plant pigments and flavonoids. Flavonoids, carotenoids and anthocyanins are probably the best known of these substances due to their antioxidant properties. Carotenoids: Structure and Function in the Human Body presents comprehensive coverage of carotenoids. The text covers the scientific literature and clinical significance of this organic pigment, with an emphasis on its therapeutic potential. The authors approach carotenoids from a range of perspectives, from their structural and physicochemical properties to their distribution in nature, interaction with the human metabolism, and use as a coloring agent in various products. The intake, metabolism and secretion of anthocyanins in the human body are covered in-depth, as are the biosynthetic pathways through which these compounds are synthesized in the natural system. Factors affecting stability and extraction are listed, and health-related uses and biological activities are covered in great detail. Present and future trends in carotenoid research are also presented. This book provides a solid background in carotenoids for researchers and professionals in food science, food technology, nutrition, biology, chemistry and medical sciences.

Advanced EPR: Applications in Biology and Biochemistry provides an up-to-date survey of existing EPR techniques and their applications in biology and biochemistry, and also provides a wealth of ideas for future developments in instrumentation and theory. The material is broadly organized into four parts. In the first part (chapters 1 to 6) pulsed EPR is discussed in detail. The second part (chapters 7 to 12) provides detailed discussions of a number of novel and experimental methods. The third part comprises seven chapters on double-resonance techniques, five on ENDOR and two on optically- and reaction yield-detected resonance. The final part is devoted to a thorough discussion of a number of new developments in the application of EPR to various biological and biochemical problems. Advanced EPR will interest biophysicists, physical biochemists, EPR spectroscopists and others who will value the extensive treatment of pulsed EPR techniques, the discussion of new developments in EPR instrumentation, and the integration of theory and experimental details as applied to problems in biology and biochemistry.