Broad in scope, this book describes the general theory and practice of using the Electron Capture Detector (ECD) to study reactions of thermal electrons with molecules. It reviews electron affinities and thermodynamic and kinetic parameters of atoms, small molecules, and large organic molecules obtained by using various methods.
* Summarizes other methods for studying reactions of thermal electrons with molecules
* Discusses applications in analytical chemistry, physical chemistry, and biochemistry
* Provides a data table of electron affinities
Autorentext
E. C. M. CHEN is Professor Emeritus in the Department of Natural and Applied Sciences at the University of Houston-Clear Lake.
E. S. CHEN is formerly of the Center for Research on Parallel Computation at Rice University in Houston, Texas.
Klappentext
Covers the general theory and practice of using an Electron Capture Detector (ECD) to study reactions of thermal electrons with molecules
In 1897, J. J. Thompson "discovered" the electron. Around the same time, Mikhail Semenovich Tswett presented a lecture on his novel method of dynamic adsorption analysis, soon known as chromatography. These achievements laid the groundwork for James Lovelock, who fifty years later observed the perturbation of ion currents by the reactions of thermal electrons with molecules. Lovelock's invention of the Electron Capture Detector (ECD) created an instrument for measuring the properties of these compounds and the reactions involved.
Today, with the ECD in widespread use and many molecular affinities and rate constants for thermal electron attachment measured, it is an appropriate time to review the techniques for studying the reactions of thermal electrons with molecules. The Electron Capture Detector and the Study of Reactions with Thermal Electrons provides just such a timely review, as well as a thorough evaluation of the results attained thus far. In addition, this text:
* Summarizes other methods for studying reactions of thermal electrons with molecules
* Reviews electron affinities and thermodynamic and kinetic parameters of atoms, small molecules, and large organic molecules obtained using various techniques
* Describes ECD applications in analytical chemistry, physical chemistry, and biochemistry
* Provides an Appendix with electron affinities in tabular form
With coverage ranging from the history of the electron to definitions and nomenclature, experimental procedures, and modern applications, the scope of this text is greater than any other available book on the subject of negative ions. Professionals and graduate students in analytical, physical, and environmental chemistry can now turn to The Electron Capture Detector and the Study of Reactions with Thermal Electrons for a comprehensive guide to the theory and practice of ECD.
Inhalt
Foreword xiii
Preface xv
1. Scope and History of the Electron 1
1.1 General Objectives and Organization 1
1.2 General Scope 2
1.3 History of the Electron 4
References 6
2. Definitions, Nomenclature, Reactions, and Equations 8
2.1 Introduction 8
2.2 Definition of Kinetic and Energetic Terms 8
2.3 Additional Gas Phase Ionic Reactions 15
2.4 Electron Affinities from Solution Data 16
2.5 Semi-Empirical Calculations of Energetic Quantities 17
2.6 Herschbach Ionic Morse Potential Energy Curves 18
2.7 Summary 19
References 20
3. Thermal Electron Reactions at the University of Houston 22
3.1 General Introduction 22
3.2 The First Half-Century, 1900 to 1950 23
3.3 Fundamental Discovery, 1950 to 1960 25
3.4 General Accomplishments, 1960 to 1970 27
3.4.1 Introduction 27
3.4.2 The Wentworth Group 28
3.4.3 Stable Negative-Ion Formation 28
3.4.4 Dissociative Thermal Electron Attachment 33
3.4.5 Nonlinear Least Squares 35
3.5 Milestones in the Wentworth Laboratory and Complementary Methods, 1970 to 1980 37
3.6 Negative-Ion Mass Spectrometry and Morse Potential Energy Curves, 1980 to 1990 40
3.7 Experimental and Theoretical Milestones, 1990 to 2000 41
3.8 Summary of Contributions at the University of Houston 42
References 43
4. Theoretical Basis of the Experimental Tools 47
4.1 Introduction 47
4.2 The Kinetic Model of the ECD and NIMS 47
4.3 Nondissociative Electron Capture 50
4.4 Dissociative Electron Attachment 59
4.5 Electron Affinities and Half-Wave Reduction Potentials 64
4.6 Electron Affinities and Ionization Potentials of Aromatic Hydrocarbons 66
4.7 Electron Affinities and Charge Transfer Complex Energies 67
4.8 Summary 71
References 73
5. Experimental Procedures and Data Reduction 75
5.1 Introduction 75
5.2 Experimental ECD and NICI Procedures 76
5.3 Reduction of ECD Data to Fundamental Properties 85
5.3.1 Introduction 85
5.3.2 Acetophenone and Benzaldehyde 86
5.3.3 Benzanthracene, Benz[a]pyrene, and 1-Naphthaldehyde 87
5.3.4 Carbon Disulfide 89
5.3.5 Nitromethane 90
5.3.6 Consolidation of Electron Affinities for Molecular Oxygen 91
5.4 Reduction of Negative-Ion Mass Spectral Data 93
5.5 Precision and Accuracy 96
5.6 Evaluation of Experimental Results 97
5.7 Summary 101
References 101
6. Complementary Experimental and Theoretical Procedures 103
6.1 Introduction 103
6.2 Equilibrium Methods for Determining Electron Affinities 105
6.3 Photon Techniques 110
6.4 Thermal Charge Transfer Methods 116
6.5 Electron and Particle Beam Techniques 121
6.6 Condensed Phase Measurements of Electron Affinities 124
6.7 Complementary Theoretical Calculations 125
6.7.1 Atomic Electron Affinities 126
6.7.2 Polyatomic Molecules 128
6.8 Rate Constants for Attachment, Detachment, and Recombination 132
6.9 Summary 134
References 134
7. Consolidating Experimental, Theoretical, and Empirical Data 139
7.1 Introduction 139
7.2 Semi-Empirical Quantum Mechanical Calculations 140
7.3 Morse Potential Energy Curves 150
7.3.1 Classification of Negative-Ion Morse Potentials 151
7.3.2 The Negative-Ion States of H 2 153
7.3.3 The Negative-Ion States of I 2 156
7.3.4 The Negative-Ion States of Benzene and Naphthalene 157
7.4 Empirical Correlations 161
7.5 Summary 165
References 166
8. Selection, Assignment, and Correlations of Atomic Electron Affinities 168
8.1 Introduction 168