Organic Structures From Spectra

Organic Structures from Spectra Fourth Edition i ii Organic Structures from Spectra Fourth Edition L D Field University of New South Wales, Australia S Sternhell University of Sydney, Australia J R Kalman University of Technology Sydney, Australia JOHN WILEY AND SONS LTD Chichester New York Brisbane Toronto Singapore iii Copyright C 2007 by John Wiley and Sons All rights reserved etc.. etc.. etc. iv CONTENTS _______________________________________________________________ PREFACE LIST OF TABLES LIST OF FIGURES 1 INTRODUCTION 1.1 1.2 1.3 1.4 1.5 1.6 GENERAL PRINCIPLES OF ABSORPTION SPECTROSCOPY CHROMOPHORES DEGREE OF UNSATURATION CONNECTIVITY SENSITIVITY PRACTICAL CONSIDERATIONS 2 ULTRAVIOLET (UV) SPECTROSCOPY 2.1 2.2 2.3 2.4 2.5 10 2.6 2.7 IMPORTANT UV CHROMOPHORES THE EFFECT OF SOLVENTS 10 14 ABSORPTION RANGE AND THE NATURE OF IR ABSORPTION EXPERIMENTAL ASPECTS OF INFRARED SPECTROSCOPY GENERAL FEATURES OF INFRARED SPECTRA IMPORTANT IR CHROMOPHORES IONIZATION PROCESSES INSTRUMENTATION MASS SPECTRAL DATA REPRESENTATION OF FRAGMENTATION PROCESSES FACTORS GOVERNING FRAGMENTATION PROCESSES EXAMPLES OF COMMON TYPES OF FRAGMENTATION 5 NUCLEAR MAGNETIC RESONANCE (NMR) SPECTROSCOPY 5.1 5.2 5.3 5.4 5.5 5.6 5.7 7 7 8 8 9 4 MASS SPECTROMETRY 4.1 4.2 4.3 4.4 4.5 4.6 1 3 3 4 5 5 BASIC INSTRUMENTATION THE NATURE OF ULTRAVIOLET SPECTROSCOPY QUANTITATIVE ASPECTS OF ULTRAVIOLET SPECTROSCOPY CLASSIFICATION OF UV ABSORPTION BANDS SPECIAL TERMS IN ULTRAVIOLET SPECTROSCOPY 3 INFRARED (IR) SPECTROSCOPY 3.1 3.2 3.3 3.4 vii xi xiii 1 THE PHYSICS OF NUCLEAR SPINS AND NMR INSTRUMENTS CONTINUOUS WAVE (CW) NMR SPECTROSCOPY FOURIER-TRANSFORM (FT) NMR SPECTROSCOPY CHEMICAL SHIFT IN 1H NMR SPECTROSCOPY SPIN-SPIN COUPLING IN 1H NMR SPECTROSCOPY ANALYSIS OF 1H NMR SPECTRA RULES FOR SPECTRAL ANALYSIS 15 15 16 16 17 21 21 23 24 28 29 29 33 33 37 39 40 50 53 55 v Contents 6 13C NMR SPECTROSCOPY 6.1 6.2 6.3 65 13C NMR SPECTRA COUPLING AND DECOUPLING IN DETERMINING 13C SIGNAL MULTIPLICITY USING DEPT SHIELDING AND CHARACTERISTIC CHEMICAL SHIFTS IN 13C NMR SPECTRA 7 MISCELLANEOUS TOPICS 65 67 70 75 / 7.1 7.2 7.3 7.4 7.5 7.6 DYNAMIC PROCESSES IN NMR - THE NMR TIME-SCALE THE EFFECT OF CHIRALITY THE NUCLEAR OVERHAUSER EFFECT (NOE) TWO DIMENSIONAL NMR THE NMR SPECTRA OF "OTHER NUCLEI" SOLVENT - INDUCED SHIFTS 75 77 79 80 84 84 8 DETERMINING THE STRUCTURE OF ORGANIC MOLECULES FROM SPECTRA 85 9 PROBLEMS 89 89 373 383 419 9.1 9.2 9.3 9.4 ORGANIC STRUCTURES FROM SPECTRA THE ANALYSIS OF MIXTURES PROBLEMS IN 2-DIMENSIONAL NMR NMR SPECTRAL ANALYSIS APPENDIX 444 INDEX 451 vi PREFACE _______________________________________________________________ The derivation of structural information from spectroscopic data is an integral part of Organic Chemistry courses at all Universities. At the undergraduate level, the principal aim of such courses is to teach students to solve simple structural problems efficiently by using combinations of the major techniques (UV, IR, NMR and MS), and over more than 25 years we have evolved a course at the University of Sydney, which achieves this aim quickly and painlessly. The text is tailored specifically to the needs and philosophy of this course. As we believe our approach to be successful, we hope that it may be of use in other institutions. The course has been taught at the beginning of the third year, at which stage students have completed an elementary course of Organic Chemistry in first year and a mechanistically-oriented intermediate co