Table Of ContentChemical Spectroscopy and Photochemistry
in the Vacuum-Ultraviolet
NATO ADVANCED STUDY INSTITUTES SERIES
Proceedings of the Advanced Study Institute Programme, which aims
at the dissemination of advanced knowledge and
the formation of contacts among scientists from different countries
The series is published by an international board of publishers in conjunction
with NATO Scientific Affairs Division
A Life Sciences Plenum Publishing Corporation
B Physics London and New York
C Mathematical and D. Reidel Publishing Company
Physical Sciences Dordrecht and Boston
D Behavioral and Sijthoff International Publishing Company
Social Sciences Leiden
E Applied Sciences Noordhoff International Publishing
Leiden
Series C - Mathematical and Physical Sciences
Volume 8 - Chemical Spectroscopy and Photochemistry in the Vacuum-Ultraviolet
Chemical Spectroscopy
and Photochemistry
in the Vacuum-Ultraviolet
Proceedings of the Advanced Study Institute, held under the
Auspices of NATO and the Royal Society of Canada,
August 5-17, 1973, Valmorin, Quebec, Canada
edited by
c.
SAN D 0 R F Y, Universite de Montreal
P. J. AU S L 00 S, u.s. National Bureau of Standards
M. B. ROB IN, Bell Laboratories
D. Reidel Publishing Company
Dordrecht-Holland / Boston-U.S.A.
Published in cooperation with NATO Scientific Affairs Division
Library of Congress Catalog Card Number 73-91209
ISBN-13: 978-94-010-2155-5 e-ISBN-13: 978-94-010-2153-1
DOl: 10.1007/978-94-010-2153-1
Published by D. Reidel Publishing Company
P.O. Box 17, Dordrecht, Holland
Sold and distributed in the U.S.A., Canada, and Mexico
by D. Reidel Publishing Company, Inc.
306 Dartmouth Street, Boston, Mass. 02116, U.S.A.
All Rights Reserved
Copyright © 1974 by D. Reidel Publishing Company, Dordrecht
Softcover reprint of the harcover 1st edition 1974
No part of this book may be reproduced in any form, by print, photoprint, microfilm,
or any other means, without written permission from the publisher.
CONTENTS
PREFACE xv
LIST OF PARTICIPANTS XVII
VACUUM ULTRAVIOLET AND PHOTOELECTRON SPECTROSCOPY - HISTORICAL
BACKGROUND AND SURVEY
W.C. PRICE 1
- V.U.V. Spectra of Polyatomic Molecules 1
- Photoionization 7
- Photoelectron Spectroscopy 8
- References 11
ASPECTS OF MOLECULAR RYDBERG STATES
M.B. ROBIN 13
- References 23
PHOTOELECTRON SPECTROSCOPY
D. W. TURNER 25
- Introduction.- Electrons and Photons 25
- Some EXperimental Aspects of Electron Energy Analysis 26
- Light Sources 27
- Photoelectron Bands Designated According to the Ionic
States 28
- Vibrational Fine Structure 30
Vibrational Fine Structure in the Third Band of
Formaldehyde 32
Vibrational Fine Structure in the Ketene Photoelectron
Spectrum 32
Vertical Ionization 34
Interpretative Methods Involving Molecular Orbital Cal-
culations 35
Correlations between P.E. Spectral Data and Other
Physical Parameters 38
Photoelectron Spectra of Transient Species 39
Photoelectron Spectra from Solids 40
References 42
ABSOLUTE INTENSITIES AND CLASSIFICATION OF TRANSITIONS IN
ELECTRON IMPACT SPECTROSCOPY
E.N. LASSETTRE 43
- Introduction 43
- Generalized Oscillator St~engths 43
- Determination of Oscillator Strengths 46
Oscillator Strengths Obtained by Extrapolation 46
Optical Oscillator Strengths from Forward Scattering 48
The names of those who actually delivered the lectures are underlined.
VI CONTENTS
- Classification of Transitions. Dipole-Quadrupole Behavior 51
Franck-Condon Principle. Invariance in Relative Intensities 58
Singlet-Triplet Transitions 60
Strongly Forbidden Transitions at Low Kinetic Energies 60
Identification of Triplets by Positive Ion Scattering 61
- Recent Results 62
Deviations from Born Approximation at Small Scattering
Angles. Selection Rules 62
Singlet-Triplet Excitation at High Kinetic Energy.
11S-23S Transition in Helium 63
Theoretical Study of Singlet-Triplet Selection Rules 65
Other Singlet-Triplet Transitions 65
Calculation of Singlet-Triplet Energy Differences 66
Excited Triplet of H20 66
Other Recent Researches 68
- Addendum on Benzene 68
- References 70
PHOTOIONIZATION OF FREE RADICALS
J. BERKOWITZ 75
- Methods of Production 77
- Available Data 78
Hydrocarbon and Fluorocarbon Radicals 79
Atmospheric Radicals 82
0(3p) 82
N(4S) 85
OH 86
03 and HN03 88
- References 91
PHOTOELECTRON SPECTROSCOPY OF MOLECULAR BEAMS
J. BERKOWITZ 93
- Introduction and Chemical Studies 93
- Physical Studies 99
Comparison of Photoelectron Intensities and Franck
Condon Factors in the Photoionization of H2,
HD and D2 101
Rotational Band Shapes in the Photoelectron Spectra
of HF and DF 103
Spin-Orbit Coupling and the Ratio of Photoionization
Cross Sections in Some Atoms 107
- Summary and Conclusions 108
- References 109
CONTENTS VII
HIGH RESOLUTION VACUUM ULTRAVIOLET SPECTROSCOPY OF
DIATOMIC MOLECULES
A.E. DOUGLAS 113
- Instrumentation 113
Spectrographs 114
Sources 116
- Spectra 118
Spectra of Valence States 119
Spectra of Rydberg States 120
BH 123
Nitric Oxide 123
Nitrogen 124
Fluorine 125
Hydrogen Fluoride 125
- Conclusions 127
- References 127
OPTICAL PROPERTIES OF LIQUIDS IN THE VACUUM UV
R.D. BIRKHOFF, ~.N. HAMM, M.W. WILLIAMS, E.T. ARAKAWA
and L.R. PAINTER 129
- Introduction 129
- EXperimental Background 130
- Theory 131
- Carbon Ring Liquids 132
- Water 132
- Other Liquids 139
- Discussion 142
- References 146
THE FAR ULTRAVIOLET ABSORPTION SPECTRA OF ORGANIC
MOLECULES: LONE PAIRS AND DOUBLE BONDS
C. SANDORFY 149
- Introduction 149
- Halogen Derivatives of Methane 150
- Halogen Derivatives of Ethane 159
- Ethylene Derivatives 162
- Benzene Derivatives 165
- MOlecules Containing Divalent Sulfur 169
- References 173
THE ETHANE PROBLEM
C. SANDORFY 177
- The Ground State 177
- The Ion 179
- The Ultraviolet Spectra 181
- Possible Weak Transitions 186
- The Primary Steps 188
- References 189
VIII CONTENTS
A POT-POURRI OF ULTRAVIOLET AND PHOTOELECTRON SPECTRA OF
IODIDES
D.R. SALAHUB and R.A. BOSCHI 191
- PE Spectrum of Vinyl Iodide 191
- UV Spectra of Alkyl Iodides 192
- PE Spectra of F1uoroiodoethanes 193
- References 194
BEYOND THE ORBITAL APPROXIMATION
R. DAUDEL 197
- The Need for a Language Adapted to Very Elaborate
Wave-Functions 197
- The Loge Theory 198
Change in the Localizability of Electrons during
Ionization 203
The Localizability of the Electron as a Starting
Point to Calculate an Elaborate Wave-Function 205
Loge Theory and Exciton Localizability 209
References 210
NATURAL AND MAGNETIC CIRCULAR DICHROISM SPECTROSCOPY IN
THE VACUUM ULTRAVIOLET
O. SCHNEPP 211
- Introduction 211
General 211
Natural Circular Dichroism 212
Magnetic Circular Dichroism 213
- Instrumentation 214
- The Natural CD Spectra of Benzene Chromophores 216
- The Natural CD Spectra of Ethylene Chromophores 220
- MCD Spectra of Benzene and Toluene 221
--References 222
(H3C)ZC =C(CH3)2, (H3C)2BN(CH3)2, (H3C)BF AND (H3C)3B.
FURTHER EVIDENCE FOR A TT -> (J* ASSIGNMENT OF THE OLEFIN
UV "MYSTERY" BAND
W. FUSS and H. BOCK 223
- Helium (I) PE Spectra 225
- Far UV Spectra 226
- Concluding Remarks 231
- References 234
PHOTOELECTRON SPECTRA OF MODERATE SIZED MOLECULES
D.C. FROST, F.G. HERRING and C.A. McDOWELL 237
- Introduction 237
- The Interpretation of the PE Spectra of Structurally
Similar Molecules 239
CONTENTS IX
- A Comparison of the Bonding of First and Second Row
p-Block Elements 240
- Photoelectron Studies of the Bonding of Particular
Elements 242
- The Investigation of "Through Space" and "Through
Bond" Interactions 242
- The Correlation of PES with UV Spectra and Other
Techniques 243
- Theoretical Studies 244
- References 245
HAM - A SEMI-EMPIRICAL MO THEORY
L. RSBRINK, C. FRIDH and E. LINDHOLM 247
- Introduction 247
- The HAM Method 247
- Shielding (preliminary form) 250
- Electrostatic Interaction (preliminary form) 250
- Results 251
- References 251
AB INITIO CALCULATIONS FOR EXCITED STATES OF MOLECULES
S.D. PEYERIMHOFF and R.J. BUENKER 257
- Introduction 257
- Geometrical Aspects. 258
Use of Ab Initio Walsh-Type Diagrams 261
Some Examples 264
- Calculation of Vertical Transition Energies 267
- Consideration of the Vibrational Structure of
Electronic Transitions 278
- References and Footnotes 285
THRESHOLD ELECTRON-IMPACT SPECTROSCOPY
H.H. BRONGERSMA 287
- Introduction 287
- Interaction of Electrons and Molecules 288
- Experimental Techniques 290
- Applications of Threshold Methods 294
Saturated Hydrocarbons 295
Olefins 296
Other Unsaturated Hydrocarbons 298
Molecules Containing a Carbonyl Group 299
Molecules Containing a Nitrogen Atom 300
Other Molecules 301
- Conclusions 302
- References 303
x
CONTENTS
SPECTRA OF FREE RADICALS AND MOLECULAR IONS PRODUCED BY
VACUUM ULTRAVIOLET PHOTOLYSIS IN LOW-TEMPERATURE MATRICES
D.E. MILLIGAN and M.E. JACOX 305
- General Principles 305
- Stabilization and Spectra of Free Radicals 307
- Stabilization and Spectra of Molecular Ions 309
- References 314
RYDBERG STATES OF DIATOMIC AND POLYATOMIC MOLECULES
V. McKOY and T. BETTS 317
- Introduction 317
- Atomic Calibration 320
- Results 321
- Conclusions 334
- References 335
THEORY OF INTRAVALENCY AND RYDBERG TRANSITIONS IN MOLECULES
O. SINANOGLU 337
- Contents 337
- Questions 338
- Theory of Excited States, Non-Closed Shell States 340
Semi-Internal Orbitals 341
The "Charge Wave Function, If c" of a Non-Closed Shell State 342
Energy of a Non-Closed Shell State 348
- Relation of the Intravalency and Rydberg States of
Spectra 350
- Classification of Transitions into Intravalency,
Pre-Rydberg and Rydberg Types 353
- Spectral Form of the Charge Wave Function of an
Intravalency State 356
- The Charge Wave Function of a Pre-Rydberg State 357
- Electric Dipole Oscillator Strengths of Intravalency(V)
and Pre-Rydberg(pR) Transitions 361
- Inner Ionization Potentials; Excited Core Rydberg
Series Limits 365
- Theory of Excited States of Molecules.- Many Center
Aspects 366
Intravalency and Pre-Rydberg States of Molecules
with RHF-MO(SCF}/NCMET 366
The lntravalency AO Pool 369
Molecular Semi-Internal Orbitals from the V-AO-Pool;
Problems of the United Atom 373
The Spectral Charge Wave Function of a Molecular
Intravalency State (V) and of a Pre-Rydberg
State(pR} 379
- What is a Rydberg Orbital ? 380
- References and Footnotes 381
- Appendix 384
