Rotational Spectra and Molecular Structure

PrefaceChapter 1 Rotational Spectra 1-1. Energy Levels and Rotational Transitions 1-2. Information Contained in Rotational SpectraChapter 2 Rigid Rotor 2-1. Introduction 2-2. Molecular Parameters 2-3. Classes of Molecules 2-4a. Rigid Linear Molecules 2-4b. Spectrum and Selection Rules 2-5a. Rigid Symmetric Top Molecules 2-5b. Spectrum and Selection Rules 2-6a. Rigid Asymmetric Top Molecules 2-6b. Matrix Elements of E(κ) 2-6c. Asymmetric Rotor Functions 2-6d. Selection Rules 2-6e. K Doubling in an Asymmetric Rotor 2-6f. Graphical Methods for Determining κ and (A — C)/2 2-7. Rotational Transition Intensities 2-8. Statistical Weights 2-9. Nuclear Spin Statistics for Linear Molecules 2-10a. Nuclear Spin Statistics for Symmetric Tops 2-10b. Rotational Wave Functions 2-10c. Spin Wave Functions 2-1la. Nuclear Spin Statistics for Asymmetric Tops 2-11b. Rotational Wave Functions 2-11c. Spin Wave Functions 2-12a. Dipole Matrix Elements 2-12b. Dipole Matrix Elements for a Linear Molecule 2-12c. Dipole Matrix Elements for a Symmetric Rotor 2-12d. Dipole Matrix Elements for an Asymmetric Rotor 2-13. Transition Strengths and Approximate Wave Functions for Near Symmetric Tops Chapter 3 Centrifugal Distortion, Coriolis Coupling, and Fermi Resonance 3-1. Introduction 3-2. Classical Appearance of Centrifugal and Coriolis Forces 3-3. Centrifugal Distortion in a Linear Molecule 3-4. Centrifugal Distortion in Symmetric Top Molecules 3-5. The Coriolis Coupling Constant 3-6a. l-Type Doubling in Linear Molecules 3-6b. Direct l-Type Transitions 3-7a. Degenerate Coriolis Splitting 3-7b. l-Type Doubling in Symmetric Top Molecules 3-7c. Energy Levels and Effects of Centrifugal Distortion 3-8. Dipole Matrix Elements and Selection Rules for l-Doubling 3-9. Fermi Resonance in Linear Molecules 3-10a. Nonrigid Effects in Asymmetric Rotors 3-10b. Perturbation Treatment of Vibration-Rotation Hamiltonian 3-10c. Interactions for Near Degeneracies 3-11. Coriolis Coupling Effects on Rotational Constants 3-12. Centrifugal Distortion in Asymmetric Tops 3-13. Fermi Resonance in Nonlinear Molecules Chapter 4 Molecular Structure 4-1. Internuclear Distances and Moments of Inertia 4-2. r0 Structure 4-3. rs Structure 4-4a. Linear Molecules 4-4b. Comparison of r0 and rs Structures for Linear Molecules 4-5. Off-Axis Substitution in a Symmetric Top 4-6a. Planar Asymmetric Tops 4-6b. Nonplanar Asymmetric Tops 4-7. Structure Determinations When All Atoms are Not Isotopically Substituted 4-8a. Determination of Coordinates near Principal Axes:Linear Molecules 4-8b. Near Axis Coordinates in Asymmetric Tops 4-8c. Coordinates of Atoms near the COM in an Asymmetric Top with a Plane of Symmetry 4-9a. The Inertia Defect 4-9b. Planar Molecules 4-9c. Inertia Defect and Molecular Structure of Planar Molecules 4-9d. Inertia Defect in Nonplanar Molecules 4-10. Variation of Bond Length with Isotopic Substitution 4-11. Values and Limitations of the Average Structure Chapter 5 Nuclear Quadrupole Coupling 5-1. Quadrupole Nuclei in Molecules 5-2. Origin of the Quadrupole Interaction 5-3. Matrix Elements of HQ 5-4. First-Order Quadrupole Energy 5-5. Second-Order Quadrupole Energy 5-6. Molecules with Two Quadrupole Nuclei 5-7. Molecules with Three Quadrupole Nuclei 5-8. Quadrupole Hyperfine Structure in Excited Vibrational States 5-9. Relative Intensities of Quadrupole Components Chapter 6 Internal Rotation 6-1a. Introduction 6-1b. Physical Models 6-1c. Potential Energy and Hindered Rotation 6-2. High Potential Barriers 6-3a. Energy Levels, Selection Rules, and Intensities for a High Barrier 6-3b. A Single Internal Rotor 6-3c. Two Equivalent Internal Rotors 6-4. The PAM for a Symmetric Top Molecule 6-5. The IAM for a Symmetric Top Molecule 6-7. IAM for Asymmetric Top Molecules 6-8. Low Barriers 6-9. Completely Asymmetric Molecules 6-10. Internal Rotation Barriers from Intensities 6-11. Internal Barriers from Vibration-Rotation Interactions 6-12. Excited Torsional States 185 6-13a. Coriolis Interactions and Internal Rotation in Symmetric Top Molecules 6-13b. Coriolis Interactions in Excited Torsional States of Asymmetric Rotors 6-14. V6 Contributions to the Torsional Barrier 6-15. Internal Rotation and Nuclear Quadrupole Coupling 6-16a. Molecules with Two Equivalent Methyl Groups 6-16b. Kinetic Energy 6-17. Symmetric Tops with Three Methyl Groups 6-18. Rotational Isomerism 6-19. Barriers Determined from Rotational Spectra Chapter 7 Inversion 7-1. Characteristics of the Inversion Motion 7-2. Properties of the Inversion Wave Functions 7-3. Inversion in Symmetric Top Molecules 7-4a. Some Potential Functions for the Twofold Inversion Barrier 7-4b. Morse-Stuckelberg Potential 7-4c. Dennison-Uhlenbeck Potential 7-4d. Rosen-Morse Potential 7-4e. Manning Potential 7-4f. Wall-Glocker Potential 7-4g. Newton-Thomas Potential 7-4h. Sutherland-Costain Potential 7-4i. Harmonic Oscillator Perturbed by a Gaussian Barrier 7-4j. Quartic Oscillator 7-4k. Mixed Harmonic-Quartic Potential 7-5. Inversion-Vibration Interactions 7-6. Reduced Mass for NH3-like Symmetric Tops 7-7. Rotational Dependence of Inversion Splittings in Symmetric Tops 7-8. Inversion Transitions in Ammonia 7-9a. Inversion in Asymmetric Tops 7-9b. Selection Rules for Asymmetric Tops 7-9c. Types of Barriers 7-9d. Application of Symmetric Top Potential Functions to Asymmetric Tops 7-9e. Reduced Mass for Inversion in an Asymmetric Top 7-9f. Rotational Dependence of the Inversion Splittings in an Asymmetric Rotor 7-10. Inversion-Inversion Coupling 7-11. Inversion and Internal Rotation—The Methyl Amines 7-12a. Inversion in Near-Planar Molecules 7-12b. Inertial Defect 7-12c. Satellites and Intensities 7-12d. Stark Effect 7-12e. Far Infrared Spectrum 7-12f. Variation of Rotational Constants with Vibrational State 7-13. Vibration-Rotation Interactions Chapter 8 Stark Effect 8-1. Introduction 8-2. General Properties of the Stark Effect 8-3. Matrix Elements of Ht 8-4. First-Order Stark Effect 8-5. Second-Order Stark Effect 8-6. High Field Stark Effect and Higher-Order Perturbation Terms 8-7. Stark Effect for Near Degeneracies 8-8a. Stark Effect and Quadrupole Hyperfine Structure 8-8b. Weak Field with a Single Quadrupole Nucleus (με << eqQ) 8-8c. Strong Field with a Single Quadrupole Nucleus (με >> eqQ) 8-8d. Intermediate Case (με ≈ eqQ) 8-8e. Near Degeneracies 8-9. Polarizability 8-10a. Stark Splittings and Relative Intensities 8-10b. ΔM = 0 Transitions 8-10c. ΔM = ± 1 Transitions 8-10d. Intensities in the Presence of Hyperfine Structure 8-11a. Stark Effect in a Linear Molecule—OCS 8-11b. Stark Effect for an l-Type Doublet 8-11c. Stark Effect in a Symmetric Top Molecule—CH3F 8-11d. Stark Effect in an Asymmetric Rotor—CH3CHF2 8-11e. Stark Effect in a Ð Electronic State—NO 8-12. Stark Effect and Hindered Internal Motions 8-13. Dipole Moment Measurement Techniques 8-14. Stark Effects in Rapidly Varying Fields 8-15. Variation of μ with Isotopic Substitution and with Vibrational StateChapter 9 Instrumentation 9-1. Spectroscopy in the Microwave Region 9-2. General Qualities of the Spectrometer 9-3a. Characteristics of Microwave Spectrometers 9-3b. Radiation Sources 9-3c. Source Stabilization 9-3d. Waveguide Stark Cell 9-3e. Modulation, Detection, and Display 9-3f. Frequency Measurements 9-3g. Millimeter and Submillimeter Techniques 9-4. Relative Intensity and Line Width Measurement 9-5. Parallel Plate Spectrometers 9-6. High Temperature and Molecular Beam Spectroscopy 9-7. Applications of Double-Resonance and Beam-Maser Spectrometers 9-8. Study of Free Radicals and Unstable Species 9-9. Zeeman Effect Spectrometers Appendix 1 References Appendix 2 Short Table of Physical Constants, Conversion Factors, and Waveguide Nomenclature Appendix 3 Evaluation of E(κ) Appendix 4 Derivation of the Hamiltonian for Treating the Vibration-Rotation Interaction Problem Appendix 5 Derivation of the Inertial Defect Appendix 6 Coupling of Angular Momentum Vectors Appendix 7 The Van Vleck TransformationAppendix 8 Internal Rotation Splittings for the IAM Appendix 9 Barriers to Internal Rotation Determined by Microwave Spectroscopy Appendix 10 Vanishing of Odd-Orde'r Nondegenerate Stark Corrections Appendix 11 Mathieu's Equation Appendix 12 Perturbation Coefficients for the Internal Rotation Problem Appendix 13 Molecular Zeeman Effect Appendix 14 Stark Corrections for a Linear MoleculeAuthor IndexSubject Index