NMR Spectroscopy in Organic Chemistry

ISBN-13: 9781468417876 / Angielski / Miękka / 2013 / 382 str.

B. I. Ionin

Opis

In recent years high-resolution nuclear magnetic resonance spec- troscopy has found very wide application in organie chemistry in structural and physicochemical investigations and. also in the study of the characteristics of organic compounds which are re- lated to the distribution of the electron cloud in the molecules. The vigorous development of this method, which may really be re- garded as an independent branch of science, is the result of ex- tensive progress in NMR technology, the refinement of its theory, and the accumulation of large amounts of experimental material, which has been correlated by empiricallaws and principles. The literature directly concerned with the NMR method and its applica- tion has now grown to such an extent that a complete review of it is practically impossible. Therefore the authors have limited themselves to an examination of only the most important, funda- mental, and general investigations. The book consists of six chapters. In the first chapter we have attempted to present the fundamentals of the NMR method in such a way that the reader with little knowledge of the subject will be able to use the method in practical work for investigating simple compounds and solving simple problems. The three subsequent chapters give a deeper analysis of the method, while the last two chapters and the appendix illustrate the various applications of NMR spectroscopy in organic chemistry.

Spis treści

I. The Fundamentals of NMR Spectroscopy.- 1. Magnetic properties of matter. Nuclear moments Nuclear resonance.- 2. Observation of nuclear magnetic resonance.- 3. Spin-lattice relaxation.- 4. Line width in NMR spectra.- 5. Saturation.- 6. Rate of sweep of spectrum.- 7. Main parameters of NMR spectra.- Chemical shift.- Scale of chemical shifts of protons. References Spin-spin coupling. Simple first-order spectra.- 8. Some features of high-resolution NMR spectra.- Chemical exchange.- Internal rotation.- Spectra with masked and virtual spin—spin coupling.- Signal of a group of equivalent nuclei.- 9. High-resolution NMR spectrometers.- Calibration of NMR spectra.- 10. Scope and limits of applicability of the NMR method.- 11. Indexing of NMR spectra.- 12. Manuals and textbooks on nuclear magnetic resonance.- Literature Cited.- II. Chemical Shift.- A. Proton Chemical Shifts.- 1. Absolute scale of chemical shifts of hydrogen.- 2. Additive components of chemical shift.- 3. Atomic component of magnetic screening ?a.- Buckingham—Musher effect.- Chemical shift and donor-acceptor properties of substituents.- 4. Molecular component of magnetic screening ?M.- Chemical shifts and aromaticity.- Long-range screening. Magnetic anisotropy and stereochemistry.- 5. Additive empirical components of the chemical shift.- 6. Isotope and contact shift.- 7. Component of magnetic screening ?’ due to intermolecular interactions and macroscopic magnetic properties of sample.- Diamagnetic susceptibility of sample. External and internal references.- Anisotropy of the magnetic susceptibility of the solvent ?an. Solvents for NMR.- spectroscopy.- Polar effect. Coordination and hydrogen bond.- B. Chemical Shifts of Nuclei of Other Magnetic Isotopes.- 8. Chemical shifts of F19.- 9. Chemical shifts of C13.- 10. Chemical shifts of P31.- 11. Chemical shifts of other nuclei.- Literature Cited.- III. Spin — Spin Coupling.- 1. Spin—spin coupling between geminal protons.- 2. Spin—spin coupling between vicinal protons.- 3. Spin—spin coupling between remote protons (long-range coupling).- 4. H1 —C13 spin—spin coupling.- 5. Spin-spin coupling with the nucleus F19.- 6. Spin—spin coupling between fluorine nuclei Jff.- 7. Spin—spin coupling of protons and fluorine with magnetic nuclei of Group IV B elements.- 8. Spin—spin coupling involving P31 nuclei.- 9. Spin—spin coupling of protons and fluorine with other magnetic nuclei.- Literature Cited.- IV. Analysis of Complex Nuclear Magnetic Resonance Spectra.- A. Complete Analysis o f Spectra of Complex Systems of Nuclear Spins.- 1. System of two nonequivalent nuclei AB.- 2. System of three nonequivalent nuclei.- A2B spectrum.- ABX system.- Strongly coupled ABC system.- 3. System of four magnetic nuclei.- AA’BB’ spectra.- Analysis of strongly coupled AA’BB’ spectrum.- ABCX system.- 4. A3B2 and A3B2X system.- B Nuclear Magnetic Double Resonance.- 5. Action of strong rf field.- 6. Action of a weak perturbing field.- Literature Cited.- V. NMR Spectra and the Structure of Organic Molecules.- 1. Saturated hydrocarbons with an open chain and their functional derivatives containing no protons directly attached to heteroatoms.- Isomerism of saturated hydrocarbons.- Derivatives of saturated hydrocarbons containing heteroatoms 2. Saturated carbo- and heterocyclic compounds.- NMR spectra of three-membered rings.- Strained rings with more than three atoms.- Six-membered carbocyclic and heterocyclic.- saturated compounds.- 3. Olefinic and Acetylenic Compounds.- 4. Aromatic hydrocarbons and heterocycles.- Monosubstituted six-membered rings.- Aromatic rings with four unsubstituted protons.- Aromatic compounds with a smaller number of interacting spins.- Nonbenzoid aromatic hydrocarbons.- 5. NMR spectra of compounds with proton-containing functional groups.- Hydroxyl compounds.- Amino compounds.- Aldehydes, carboxylic acids, and their derivatives.- 6. Compounds containing atoms of fluorine, phosphorus, and other magnetic nuclei.- Literature Cited.- VI. Application of NMR Spectroscopy in Various Fields of Organic Chemistry.- 1. Intermediate reaction products and complexes.- 2. Kinetics and mechanism of organic reactions.- 3. Kinetics of exchange processes.- 4. Tautomerism and valence isomerism.- 5. Compounds containing an unpaired electron.- Literature Cited.