The Electron Capture Detector and The Study of Reactions With Thermal Electrons

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

Table of Contents:
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 8.2 Evaluation of Atomic Electron Affinities 169 8.3 Mulliken Electronegativities 178 8.4 Electron Affinities of Atomic Clusters 184 8.5 Summary 189 References 190 9. Diatomic and Triatomic Molecules and Sulfur Fluorides 193 9.1 Introduction 193 9.2 Diatomic Molecules 194 9.2.1 Electron Affinities and Periodic Trends of Homonuclear Diatomic Molecules 194 9.2.2 Electron Affinities and Morse Potential Energy Curves: Group VII Diatomic Molecules and Anions 197 9.2.3 Electron Affinities and Morse Potential Energy Curves: Group VI Diatomic Molecules and Anions 205 9.2.4 Electron Affinities and Morse Potential Energy Curves: Group IA and IB Homonuclear Diatomic Molecules and Anions 209 9.2.5 Electron Affinities and Morse Potential Energy Curves: NO and NO(-) 214 9.3 Triatomic Molecules and Anions 216 9.4 Electron Affinities and Morse Potential Energy Curves: Sulfur Fluorides and Anions 224 9.5 Summary 229 References 229 10. Negative Ions of Organic Molecules 234 10.1 Introduction 234 10.2 Electron Affinities and Potential Energy Curves for Nitrobenzene and Nitromethane 235 10.3 Electron Affinities Determined Using the Magnetron, Alkali Metal Beam, Photon, and Collisional Ionization Methods 238 10.3.1 Electron Affinities Determined Using the Magnetron Method 238 10.3.2 Electron Affinities Determined Using the AMB Method 240 10.3.3 Electron Affinities Determined Using Photon Methods 241 10.3.4 Electron Affinities Determined Using Collisional Ionization Methods 243 10.4 Electron Affinities Determined Using the ECD, NIMS, and TCT Methods 244 10.4.1 Electron Affinities of Aromatic Hydrocarbons by the ECD Method 244 10.4.2 Electron Affinities of Organic Carbonyl Compounds by the ECD Method 246 10.4.3 Electron Affinities of Organic Nitro Compounds the ECD and TCT Methods 253 10.5 Electron Affinities of Charge Transfer Complex Acceptors 257 10.6 Substituent Effect 261 10.7 Summary 263 References 263 11. Thermal Electrons and Environmental Pollutants 266 11.1 Introduction 266 11.2 Alkyl Halides 267 11.2.1 Morse Potential Energy Curves 267 11.2.2 Experimental Activation Energies 269 11.2.3 Alkyl Fluorocompounds 272 11.2.4 Electron Affinities of the Alkyl Halides 274 11.3 Aromatic Halides 276 11.3.1 Electron Affinities of Fluoro- and Chlorobenzenes 276 11.3.2 Electron Affinities from Reduction Potentials and CURES-EC 283 11.3.3 Negative-Ion Mass Spectra and Electron Affinities 284 11.4 Negative-Ion Mass Spectrometry 287 11.5 Calculation of the ECD and NIMS Temperature Dependence 291 11.6 Summary 293 References 293 12. Biologically Significant Molecules 296 12.1 Introduction 296 12.2 Electron Affinities of Purines and Pyrimidines 299 12.2.1 Predictions of Electron Affinities 299 12.2.2 Electron Affinities from Reduction Potentials 300 12.2.3 Gas Phase Measurements of Electron Affinities 302 12.2.4 Theoretical Electron Affinities 305 12.3 Electron Affinities of Biological Molecules from Reduction Potentials 307 12.4 Gas Phase Acidities of Nucleic Acids 310 12.5 Morse Potential Energy Curves for Thymine and Cytosine 311 12.6 Gas Phase Acidities and Electron Affinities of the Amino Acids 315 12.7 The Calculation of the ECD and NIMS Temperature Dependence 316 12.8 Electron Affinities of AT AU and GC 318 12.9 Radiation Damage in DNA 320 12.10 Summary 326 References 327 Appendices 329 I Glossary of Terms, Acronyms, and Symbols 331 II Structures of Organic Molecules 336 III General Least Squares 339 IV Tables of Evaluated Electron Affinities 349 Table A.1 Atoms 349 Table A1.2 Main Group Homonuclear Diatomic Molecules 351 References 352 Table A2.1 and A.2 CH Molecules 355 References 357 Table A2.3 and A2.4 CHX Molecules 357 References 359 Table A3.1 and A3.2 CHNX Molecules 360 References 361 Table A4.1 and A4.2 CHO Molecules 362 Table A4.3 and A4.4 CHOX Molecules 366 References 369 Table A5.1 and A5.2 CHON Molecules 370 Table A5.3 and A5.4 CHONX Molecules 375 References 376 Table A6.1 Bergman Dewar set 377 Table A6.2 Values Different from NIST Values (from Tables A2.1 to A5.4) 378 Table A6.3 Unpublished or Updated Gas Phase Values not in NIST Tables 380 Table A6.4 Values for Adenine, Guanine, Cytosine, Uracil, Thymine, and Their Hydrates 382 Table A6.5 Values for Charge Transfer Complex Acceptors not in NIST Tables 382 Table A6.6 Values for Chlorinated Hydrocarbons from Reduction Potentials and CURES-EC 383 Table A6.7 Values for Biological Compounds from Reduction Potentials 383 Author Index 387 Subject Index 395

About the Author :
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.

Review :
“…contains a wealth of thermochemical information.” (ChemPhysChem, 2005; Vol. 6, 9) "This book is thorough and comprehensive in its coverage of ECDs and ECDs to study the reactions with thermal electrons…" (E-STREAMS, October 2004)