Download or read book Deuterium Isotope Effects in Selected Substitution and Elimination Reactions written by Joyce Naoko Takahashi and published by . This book was released on 1960 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Enzyme Mechanism from Isotope Effects written by Paul F. Cook and published by CRC Press. This book was released on 1991-09-20 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt: Isotope effects have become one of the most powerful tools available to the enzymologist for probing enzymic mechanisms. Enzyme Mechanism from Isotope Effects presents the basic theory underlying isotope effects, including the latest findings on proton tunneling and coupled atomic notions. Specific theoretical applications are emphasized in regard to the types of information that can be obtained using isotope effects. The book also examines recent theoretical treatments of the product dependence of deuterium isotope effects, multiple isotope effects and isotope effects on intermediate partitioning. Other topics include a complete discussion of methods for measuring isotope effects, including a detailed description of the use of the isotope ratio mass spectrometer to obtain isotope effects, and a review of the literature regarding mechanistic information obtained from isotope effects for individual classes of enzyme-catalyzed reactions. Enzyme Mechanism from Isotope Effects is an excellent reference source for investigators using isotope effects in their research. The book is also valuable for reference libraries and instructors teaching courses in enzyme mechanism.

Download or read book Secondary Deuterium Isotope Effects in Bimolecular Elimination Reactions written by Bradley Bruce Basinger and published by . This book was released on 1981 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Deuterium Isotope Effects and Mechanisms of Solvolytic Elimination Reactions written by Dennis Arthur Nollen and published by . This book was released on 1979 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Deuterium Isotope Effect in the Nucleophilic Substitution Reaction of Benzyl Chlorides with Cyanide Ion written by Chih-Kuo Ho and published by . This book was released on 1969 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Secondary Deuterium Isotope Effects for Certain Acyl Transfer Reactions of Phenyl Formates written by Juan Jose Ortiz O. and published by . This book was released on 1977 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Deuterium Isotope Effects in Chemistry and Biology written by David Kritchevsky and published by . This book was released on 1960 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Deuterium Isotope Effects in the Reactions of Trans stilbene The Alpha Deuterium Effect written by Norman Tunkel and published by . This book was released on 1959 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Deuterium Isotope Effects on the Solvolysis Rates of Cyclopentyl Brosylates and Tosylates written by Jimmie Duane Christen and published by . This book was released on 1968 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The brosylates and tosylates of cyclopentanol and its 1-d1, c̲i̲s̲-2-d1, t̲r̲a̲n̲s̲-2-d1, and 2,2,5,5-d4 analogs have been synthesized and their solvolysis rates measured at 25° in 70% vol. ethanol-water. The solvoylsis reactions were monitored by a conductance method. The isotope effects, k[subscript H]/k[subscript D], observed for the brosylates and tosylates of each of the isotopically substituted cyclopentyl alcohols are as follows: 1-d1-brosylate (1.1869) and 1-31-tosylate (1l1836); c̲i̲s̲-2-d1-brosylate (1.1533) and c̲i̲s̲-2-31-tosylate (1.1577); t̲r̲a̲n̲s̲-2-d1-brosylate (1.1803) and t̲r̲a̲n̲s̲-2-d1-tosylate (1.1765); 2,2,5,5-d4-brosylate (1.8881) and 2,2,5,5-d4-tosylate (1.8863). The closeness in magnitude of the isotope effects for the c̲i̲s̲- and t̲r̲a̲n̲s̲-isomers is important in that it shows the cyclopentyl system to be very nearly planer. If they had been greatly different it would have indicated that the ring was quite puckered. More important, however, is the fact that the t̲r̲a̲n̲s̲-isotope effect is greater than the c̲i̲s̲-isotope effect. this means that specific solvation of the [underscore Beta]-hydrogens, leading to an elimination driving force, is a possible explanation of secondary deuterium isotope effects. The isotope effects for the d4-compounsd were calculated by taking the products of the squares of the c̲i̲s̲- and t̲r̲a̲n̲s̲-isotope effects. The calculated isotope effect was 1.8530 for the d4-brosylate and 1.8552 for the d4-tosylate. These vales are very near the observed values of 1.8881 and 1.8863 for the brosylate and tosylate, respectively. Because of the great precision (~0.1-0.2%) of the technique used in obtaining these results, the difference between the calculated and the observed isotope effects for both the brosylate and tosylate is considered to be a true difference. However, the closeness of the calculated and observed values does indicate an almost cumulative isotope effects which supports the hyperconjugation postulate as a possible explanation of secondary deuterium isotope rate effects. There is a very close agreement between the isotope effects for the brosylate and tosylate of any one given isotopically substituted cyclopentyl alcohol, e.g., the greatest difference exhibited was that of 0.38% for the c̲i̲s̲-compounds. This close agreement tends to indicate that when changing from one leaving group to another structurally similar leaving group there is a negligible influence on the isotope effect. Attempts were made to synthesize 2,2-d2-cyclopentyl alcohol and c̲i̲s̲-2-d1-5,5-d2-cyclopentyl alcohol and the procedures are described in the Experimental section. Unfortunately, these synthetic procedures were unsuccessful"--Abstract, leaves iii-iv.

Download or read book Deuterium and Shift Calculation written by U Fleischer and published by . This book was released on 1990-12-19 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Deuterium Isotope Effects Upon Solvolyses of Alkyl Sulfonates in Dimethyl Sulfoxide written by Keith Douglas Bowersox and published by . This book was released on 1985 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1975 with total page 1396 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Isotope Effects written by Max Wolfsberg and published by Springer Science & Business Media. This book was released on 2009-12-15 with total page 477 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the title suggests, Isotope Effects in the Chemical, Geological and Bio Sciences deals with differences in the properties of isotopically substituted molecules, such as differences in the chemical and physical properties of water and the heavy waters. Since the various fields in which isotope effects are applied do not only share fundamental principles but also experimental techniques, this book includes a discussion of experimental apparatus and experimental techniques. Isotope Effects in the Chemical, Geological and Bio Sciences is an educational monograph addressed to graduate students and others undertaking isotope effect research. The fundamental principles needed to understand isotope effects are presented in appropriate detail. While it is true that these principles are more familiar to students of physical chemistry and some background in physical chemistry is recommended, the text provides enough detail to make the book an asset to students in organic and biochemistry, and geochemistry.

Download or read book Deuterium Isotope Effects in Some Solvolysis Reactions written by Mary S. Feng and published by . This book was released on 1962 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Secondary Deuterium Isotope Effects in the Solvolysis of Propionyl D b0 s 2 2 D b2 sand 3 3 3 D b3 schlorides written by Uan Gen Kang and published by . This book was released on 1969 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Study of the Deuterium Kinetic Isotope Effect in Aromatic Substitutions written by Peter P. Klemchuk and published by . This book was released on 1957 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Deuterium and Shift Calculation written by and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1931 Vrey, Brickwedde, and Murphy discovered the hydrogen isotope deuterium. The isotopic enrichment was found to arise from the fact that the electrolysis oflight water is faster than of heavy water [1,2]. This success showed that although different isotopes of an element behave identically from a chemical standpoint the different isotopic masses nevertheless lead to both isotope effects on equilibrium as well as on rate constants of chemical reactions. Soon, ratios of equilibrium constants of isotopic reactions were called "equilibrium isotope effects" (EIE), ratios of isotopic rate constants "kinetic isotope effects" (KIE). Isotope effects have been found to be especially large for those elements which are directly involved in bond breaking and bond formation during the reaction studied [3]. Such effects are, therefore, referred to as "primary". Isotopic substitution in atomic sites which maintain all chemical bonds with their neighbors during the reaction of interest leads then only to smaller "secondary" isotope effects. Because of the unique mass relation between the different hydrogen isotopes hydrogen/deuterium isotope effects are particularly large and have attracted most attention. The largest contributions to these effects arise from changes in the vibrational frequencies of the reactants. The theory of equilibrium isotope effects has been founded by Vrey [4] and Bigeleisen [5,6] and has widely been accepted [3].