PK [subscript A] Prediction for Organic Acids and Bases /D.D. Perrin, Boyd Dempsey, and E.P. Serjeant PDF Download

Author: Douglas Dalzell Perrin
Publisher:
ISBN:
Category : Ionization constants
Languages : en
Pages : 0

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Author: D. Perrin
Publisher: Springer Science & Business Media
ISBN: 9400958838
Category : Science
Languages : en
Pages : 154

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Many chemists and biochemists require to know the ionization constants of organic acids and bases. This is evident from the Science Citation Index which lists The Determination of Ionization Constants by A. Albert and E. P. Serjeant (1971) as one of the most widely quoted books in the chemical literature. Although, ultimately, there is no satisfactory alternative to experimental measurement, it is not always convenient or practicable to make the necessary measure ments and calculations. Moreover, the massive pK. compilations currently available provide values for only a small fraction of known or possible acids or bases. For example, the compilations listed in Section 1. 3 give pK. data for some 6 000--8 000 acids, whereas if the conservative estimate is made that there are one hundred different substituent groups available to substitute in the benzene ring of benzoic acid, approximately five million tri-substituted benzoic acids are theoretically possible. Thus we have long felt that it is useful to consider methods by which a pK. value might be predicted as an interim value to within several tenths of a pH unit using arguments based on linear free energy relationships, by analogy, by extrapolation, by interpolation from existing data, or in some other way. This degree of precision may be adequate for many purposes such as the recording of spectra of pure species (as anion, neutral molecule or cation), for selection of conditions favourable to solvent extraction, and for the interpretation of pH-profiles for organic reactions.

Author: D.D. Perrin
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author: George C. Shields
Publisher: CRC Press
ISBN: 1466508787
Category : Science
Languages : en
Pages : 178

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The pKa of a compound describes its acidity or basicity and, therefore, is one of its most important properties. Its value determines what form of the compound—positive ion, negative ion, or neutral species—will be present under different circumstances. This is crucial to the action and detection of the compound as a drug, pollutant, or other active chemical agent. In many cases it is desirable to predict pKa values prior to synthesizing a compound, and enough is now known about the salient features that influence a molecule’s acidity to make these predictions. Computational Approaches for the Prediction of pKa Values describes the insights that have been gained on the intrinsic and extrinsic features that influence a molecule’s acidity and discusses the computational methods developed to estimate acidity from a compound’s molecular structure. The authors examine the strengths and weaknesses of the theoretical techniques and show how they have been used to obtain information about the acidities of different classes of chemical compounds. The book presents theoretical methods for both general and more specific applications, covering methods for various acids in aqueous solutions—including oxyacids and related compounds, nitrogen acids, inorganic acids, and excited-state acids—as well as acids in nonaqueous solvents. It also considers temperature effects, isotope effects, and other important factors that influence pKa. This book provides a resource for predicting pKa values and understanding the bases for these determinations, which can be helpful in designing better chemicals for future uses.

Author: Howard Maskill
Publisher: John Wiley & Sons
ISBN: 0470994169
Category : Science
Languages : en
Pages : 392

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A range of alternative mechanisms can usually be postulated for most organic chemical reactions, and identification of the most likely requires detailed investigation. Investigation of Organic Reactions and their Mechanisms will serve as a guide for the trained chemist who needs to characterise an organic chemical reaction and investigate its mechanism, but who is not an expert in physical organic chemistry. Such an investigation will lead to an understanding of which bonds are broken, which are made, and the order in which these processes happen. This information and knowledge of the associated kinetic and thermodynamic parameters are central to the development of safe, efficient, and profitable industrial chemical processes, and to extending the synthetic utility of new chemical reactions in chemical and pharmaceutical manufacturing, and academic environments. Written as a coherent account of the principal methods currently used in mechanistic investigations, at a level accessible to academic researchers and graduate chemists in industry, the book is highly practical in approach. The contributing authors, an international group of expert practitioners of the techniques covered, illustrate their contributions by examples from their own research and from the relevant wider chemical literature. The book covers basic aspects such as product analysis, kinetics, catalysis, and investigation of reactive intermediates. It also includes material on significant recent developments, e.g. computational chemistry, calorimetry, and electrochemistry, in addition to topics of high current industrial relevance, e.g. reactions in multiphase systems, and synthetically useful reactions involving free radicals and catalysis by organometallic compounds.

Author: Anthony J. Kinloch
Publisher: Springer Science & Business Media
ISBN: 9401577641
Category : Technology & Engineering
Languages : en
Pages : 452

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Over the last decade, or so, the growth in the use of adhesives, especially in ever more technically demanding applications, has been rapid and many major developments in the technology of adhesives have been reported. This growth has also led to attention being focused on somewhat more basic studies of the science of adhesion and adhesives, and in recent years our level of fundamental knowledge concerning the formation and mechanical performance of adhesive joints has increased dramatically. Such studies have, of course, been aided greatly by the development of the tools at the disposal of the investigators. For example, specific surface analytical techniques, such as X-ray photoelectron and secondary-ion mass spectroscopy, and the increasingly sophisticated methods of stress analysis and fracture mechanics have been put to good use in furthering our understanding of the science of adhesion and adhesives. The present book attempts to review the multidisciplined subject of adhesion and adhesives, considering both the science and technology involved in the formation and mechanical performance of adhesive joints. The author would like to thank his friends and colleagues for useful discus sions and help in the preparation of this book. I am particularly grateful to P. Cawley, J. Comyn, W. A. Lees, A. C. Roulin-Moloney, W. C. Wake, J. G. Williams and R. J. Young who have read and commented on various chapters and P. Farr for preparing the diagrams.

Author: Wade H. Shafer
Publisher: Springer
ISBN:
Category : Education
Languages : en
Pages : 328

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Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) * at Purdue University in 1 957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all con cerned if the printing and distribution of the volumes were handled by an interna tional publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Cor poration of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 28 (thesis year 1 983) a total of 10,661 theses titles from 26 Canadian and 197 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this important annual reference work. While Volume 28 reports theses submitted in-1983, on occasion, certain univer sities do report theses submitted in previous years but not reported at the time.

Author: Adrien Albert
Publisher: Springer Science & Business Media
ISBN: 9400955480
Category : Science
Languages : en
Pages : 223

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This practical manual is devised for organic chemists and biochemists who, in the course of their researches and without previous experience, need to determine an ionization constant. We are gratified that earlier editions were much used for this purpose and that they also proved adequate for the in service training of technicians and technical officers to provide a Department with a pK service. The features of previous editions that gave this wide appeal have been retained, but the subject matter has been revised, extended, and brought up to date. We present two new chapters, one of which describes the determination of the stability constants of the complexes which organic ligands form with metal cations. The other describes the use of more recently introduced techniques for the determination of ionization constants, such as Raman and nuclear magnetic resonance spectroscopy, thermometric titrations, and paper electro phoresis. Chapter 1 gives enhanced help in choosing between alternative methods for determining ionization constants. The two chapters on potentiometric methods have been extensively revised in the light of newer understanding of electrode processes and of the present state of the art in instrumen tation.

Author: A. R. Katritzky
Publisher: Elsevier
ISBN: 1483273199
Category : Science
Languages : en
Pages : 497

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Physical Methods in Heterocyclic Chemistry, Volume IV, discusses the application of physical methods to organic chemistry, and in particular to heterocyclic chemistry. Since the publication in 1963 of the first two volumes of this treatise, the application of physical methods to organic chemistry, and in particular to heterocyclic chemistry, has proceeded apace. The importance of physical methods to structure determination and to the understanding of inter- and intramolecular interactions has increased no less than the flood of new work. Heterocyclic chemists are thus faced with the necessity of having more to comprehend for the efficient execution of their own work. The present volume includes chapters on electric dipole moments and heteroaromatic reactivity, which originally appeared in Volume I, and chapters on nuclear quadrupole resonance, nuclear magnetic resonance, and infrared spectra, which originally formed part of Volume II. Also included is one new topic: dielectric absorption.

Author: Alex Avdeef
Publisher: John Wiley & Sons
ISBN: 0471450251
Category : Science
Languages : en
Pages : 313

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Many times drugs work fine when tested outside the body, but when they are tested in the body they fail. One of the major reasons a drug fails is that it cannot be absorb by the body in a way to have the effect it was intended to have. Permeability, Solubility, Dissolution, and Charged State of Ionizable Molecules: Helps drug discovery professionals to eliminate poorly absorbable molecules early in the drug discovery process, which can save drug companies millions of dollars. Extensive tabulations, in appendix format, of properties and structures of about 200 standard drug molecules.