THE J O U R N A L OF
PHYSICAL CHEMISTRY Registered in U S . Patent Office 0 Copyright, 1980, by the American Chemical Society
VOLUME 84, NUMBER 10
MAY 15, 1980
Colloque Weyl V The Fifth International Conference on Excess Electrons and Metal-Ammonia Solutions Aviemore Centre, Avieniore, Inverness-shire, Scotland June 25-29, 1979
Introductory Remarks Brian Webster Chemistry Department, University of Glasgow, Glasgow G12 8QQ. Scotland
On Februar,y 18, 1864, in Berlin, W. Weyl completed a paper entitled “Ueber Metallammonium-Verbindungen”. The paper contained a report of the preparation of a potassium--ammonia solution which Weyl interpreted in the valence theory of that time, as containing the coimpound H H .L1
where a hydrogen atom has been replaced by a pcltassium atom in an animonium group. Writing in 1871, Seeley comments upon Weyl’s results, in the following passage from J. Franklin Inst.: “...early in May, my attention was directed to the researches of Weyl on ammonium and compound aminoniums as reported in “Watts Dictionary” (article, “Sodium”), and in the last edition of “IFownes’ Chemistry”; subsequently, I compared Weyl’s original memoirs in “Poggendorffs Annalen” of 1864. Weyl’s statements andl conclusions were quite at variance !withmy own views; his alleged facts were inconsistent with my own experience. W eyl, it appeared, had actually isolated ammonium; if he represented the facts correctly all my work needed revision. I therefore at once devoted my whlole care to a verification of his results. I repeated his experiments, some of them many times, and with such precautions, modifications, and additions as the case seemed to require. The result of all is that I find that Weyl has had only an imperfect apprehension of the fundamental facts, and that thus building on a weak foundation the superstructure of reasoning and conclusion cannot stand”. QO22-3654I8Ql2Q841Q65$1.QQ/Q
In order to establish some agreement as to what are the fundamental facts pertaining to the physical and chemical properties of excess electrons, as well as to celebrate the centenary of Weyl’s discovery, an international conference was convened at the Catholic University of Lille, France in late June, 1963. It arose through the vision of Profeissor Gerard Lepoutre and was named Colloque Weyl I. Six years later, an organizing wave was sensed again by the dispersed metal-ammonia community. Under the inspiration of Professor Michael Sienko, Colloque Weyl I1 was held at Cornel1 University, Ithaca, N.Y., from June lis to 19, 1969. It was becoming apparent that the realm of excess electrons could not be confined to the W-shaped preparative tube of Weyl alone. At Colloque Weyl 111, convened from June 19 to 23,1973 at Kibbutz Hanita, Upper Galiilee, Israel, the program was broadened to permit a more general treatment of excess electrons, with topics as the metal-insulator transition, and the electronic states of disordered systems, brought into prominence. Professor Joshua Jortner sounded the clarion, and enhanced the meeting by his deep understanding of the subject. This tradition was continued under the perceptive guidancie of Professor J. L. Dye at Michigan State University, whlere Colloque Weyl IV was convened from June 30 to Ju1,y 3, 1975. The Fifth International Conferenceon Excess Electrons and Metal-Ammonia Solutions, Colloque Weyl V, was hleld a t the Aviemore Centre, Aviemore, Inverness-shire, Scotland, from June 25 to 29,1979. The accent of this meeting 0 1980 American Chemical Society
1066
J. Phys. Chem. 1980, 84, 1066-1069
was placed upon current research difficulties and new problems. The plenary lectures, which in previous Weyl Colloquia had a review character, were exchanged for session talks, which were to serve to introduce the problems presently being encountered. The compass of the meeting moved slightly toward metal-ammonia solutions although still maintaining the development instigated a t Colloque Weyl 111. The papers collected in this volume are a record of the Proceedings of Colloque Weyl V. A few contributions for various reasons are not included. It is hoped the proceedings will convey to the reader not only the facts as they are presently although imperfectly understood but also the spirit of a meeting where both “seekers and diggers”, on occasions, were trapped in Scottish mist. The organization of the meeting greatly benefited from the advice and support of the Chemical Society, through Dr. John Gibson, and the graceful presence of Miss Anne
Howard of the Chemical Society, a t Aviemore. A European accent was provided by affiliation with the Soci6t6 de Chimie Physique and the Deutsche Bunsengesellschaft fiir Physikalische Chemie. Glaxo UK Limited and the Dow Chemical Company generously provided financial assistance toward the cost of the scientific proceedings. The Chemistry Department, The University of Glasgow, provided support in many ways, while I am particularly grateful for the patience and skill with which Mrs. Jeanne Boocock and Mrs. Paddy Burnett have dealt with the secretarial matters throughout the organization of this meeting. To these persons and institutions, to the session speakers, and to the contributors, I record my sincere thanks.
Organizing Committee: G. Lepoutre (Lille), U. Schindewolf (Karlsruhe), P. Chieux (Grenoble), R. Catterall (Salford), and B, Webster (Glasgow).
COLLOQUE WEYL V (Papers as presented at the sessions.) Theme: Theoretical Practices, Techniques of Preparation, and Some Physical Properties of Metal-Solvent Solutions Session A New Perspectives €or Excess Electron Theory and Experiment. B. C. Webster, University of Glasgow, Glasgow, Scotland. Moment Theory Analysis of eROf Optical Absorption Spectra. I. Carmichael, University of Notre Dame, Notre Dame, Indiana. *Application of a Method of Moments to the Analysis of Solvated Electron Spectra in Various Solvents. M. G . De Backer, J. P. Lelieur, M. Lanno, and G . Lepoutre, Lille, France. *Statistical Model of the Hydrated Electron. W. M. Bartczak, M. Hilczer, and J. Kroh, Institute of Applied Radiation Chemistry, Technical University, Lodz, Poland. Sessio-n B Preparation and Analysis of Metal-Solvent Solutions and the Formation of Alkali Metal Anions. J. L. Dye, Michigan State University, East Lansing, Michigan. Effect of 18-Crown-6on Spectra of Potassium-Ammonia Solutions. R. L. Harris and J. J. Lagowski, University of Texas a t Austin, Austin, Texas. *Pulse Radiolysis of Macrocyclic Potential Electron Traps. R. L. Harris and J. J. Lagowski, University of Texas at Austin, Austin, Texas. Transmission Spectra of Thin Films Which Contain Alkali Metal Anions and/or Trapped Electrons. J. L. Dye, M. G . Da Gue, M. R. Yemen, J. S . Landers, and H. L. Lewis, Michigan State University, East Lansing, Michigan. Session C Optical Properties of Dilute Metal-Solvent Systems. W. A. Seddon and J. W.Fletcher, Chalk River, Canada. Solutions o f Lanthanoid Metals. W. J. Peer and J. J. Lagowski, University of Texas at Austin, Austin, Texas. Photochemistry of Solutions of Potassium in Dimethoxyethane: Electron Association to Potassium Cations. S. Jaenicke and P. Krebs, University o f Karlsruhe, Karlsruhe, West Germany. Thermodynamics of Sodium-Ammonia Solutions. U. Schindewolf and M. Werner, University of Karlsruhe, Karlsruhe, West Germany. 0022-3654/80/2084-1066$01 .OO/O
0 1980 American Chemical Society
Colloqus Weyl V
The Journal of Physical Chemistry, Vol. 84, No. 10, 1980 1067
Session D *Magnetic Properties of Dilute Metal-.Amine-Ether Solutions. R. Catterall, University of Salford, England. *Magnetic Susceptibility of Lithium-Ammonia Solutions. A. Depriester, J. Fackeure, and J. P. Lelieur, Lille, France. Spin-Lattice Relation in the Alkaline Earth-Hexaammines. M. J. Mobley, W. S. Glaunsinger, and R. F. Marzke, Arizona State IJniversity, Tempe, Arizona. *ESR Spectra of Solutions of Rb and Cs in EtNH2. R. Catterall, University of Salford, England. Theme: The Physical Nature of the Solvated Electron, and the Dynamics of Excess Electron Localization Session E *An Investigation of the Photoelectron Emission from Solutio-ns Containing Solvated Electrons and the Physical Nature of the Solvated Electron. A. M. Brodsky, Academy of Sciences, Moscow, Russia. The Significance of the Primary Energy :Distribution in Photoemission Studies of Electron Localization. J. K. Sass, N. Neff, and H. J. Lewerenz, Fritz-Haber Institute, Berlin, West Germany. *Ex0 Electrons and Solvated Electrons at Alkaline Earth Oxide Surfaces. B. C. Webster, University of Glasgow, Glasgow, Scotland. *Solvated Electrons: Cavities or Mollecular Anions. M. C. R. Symons, University of Leicester, England, and R. Catterall, university of Salford, England. Session F Dynamics of Electron Localization. D.C. Walker, University of British Columbia, Canada. Picosecond Dynamics of Electrons in Fluids. G. Kenney-Wallace, G.E. Hall, L. A. Hunt, and K , Sarantidis, University of Toronto, Toronto, Canada. Laser Photodetachment Spectra of C,F6- in Nonpolar liquids. U. Sowada and R. A. Holroyd, Brookhaven National Laboratory, Upton, New York. High Mobility Excess Electrons in the Electron Attaching Liquid Hexafluorobenzene. L. Nyaikos, C. A. M. van den Ende, J. M. Warman, and A. Hummel, Inter-1Jniversity Reactor Institute, Delft, The Netherlands. Mobility of Electrons in Ammonia Vapor of Variable Density. P. Krebs and M. Wantschik, University of Karlsruhe, Karlsruhe, West Germany. Theme: Metal-NH3 Complexes and Physical Measurements on Metal-Solvent Systems Session G Structural Studies of Metal-Ammonia Complexes. W. S. Glaunsinger, Arizona State University, Tempe, Arizona. *Low-FrequencyRaman Studies of Met,al-Ammonia Solutions. B. De Bettignies and J. P. Lelieur, Villeneuve, France. Electrical Resistivity of Ca(NH3I6,ST("&, and Ba(NHJ6. M. J. Mobley and W. S. Glaunsinger, Arizona State University, Tempe, Arizona. Inelalstic Neutron Scattering Study of Cdcium Hexaammine. R. B. Von Dreele, W. S. Glaunsinger, I. R. White, Arizona State University, Tempe, Arizona and P. Chleux, Grenoble, and P. Damay, Lille, France. *Ytterbium-Ammonia Solutions. R. Hagedorn and J. P. Lelieur, Lille, France. Ultrahigh Pressure Studies of NH3. R. C. Hanson and M. Jordan, Arizona State University, Tempe, Arizona. Electron Spin Resonance Studies of Metal-Ammonia Compounds. F. Y. Robb and W. S. Glaunsinger, Arizona State University, Tempe, Arizona. Electron Spin Resonance Studies of Alkali Metal-Ammonia Solutions. R. J. Peck and W. S. Glaunsinger, Arizona State University, Tempe, Arizona. Session H *Physical Measurements of Metal-Solvent Systems. K. G . Breitschwerdt, University of Heidelberg, Heidelberg, West Germany. Excess Electron Mobility in Ethane: Deinsity, Temperature and Electric Field Effects. W. Doldissen and W. F. Schmidt, Hahn Meitner Institute, Berlin, West Germany. Electron Mobilities of Solvated Electrons in Polar Solvents from Scavenging Rate Constants. J. A. Delaire, M. 0. Delcourt, and J. Belloni, Laboratoire de Physico-Chimie des Rayonnements, Orsay, France. Ultrasound Propagation in Metal-Ammlonia Solutions. D. B. Fenner and D. E. Bowen, University of Texas at El Paso, El Paso, Texas.
1068
The Journal of Physical Chemistry, Vol. 84, No. 10, 7980
Colloque Weyl V
Workshop Session Are There Hot Carriers in Liquid Ar, Kr, and Xe? G. Ascarelli, Department of Physics, Purdue University, West Lafayette, Indiana. Matrix Trapped and Gaseous Alkali Atoms. R. Catterall, University of Salford, England, and P. Edwards, University of Cambridge, England. *Photolysis of Frozen Alkali Metal Solutions in HMPA. R. Catterall, University of Salford, England, and P. Edwards, University of Cambridge, England. *Trapped Electrons in WMPA-Water Mixtures. K. Burton and R. Catterall, University of Salford, England. *Modification of the Raman Spectrum in the Presence of the Solvated Electron. A Study by the CARS Method. T. S. Zhuravleva, A. V. Vannikov, S. K. Akhmanov, and L. S. Aslanyan, Academy of Sciences, MOSCOW, Russia. *Charge Transfer to Solvent State: Luminescence Studies of Tryptophan in Aqueous 4.5 M CaClz Solutions a t 300 and 77 K. T. B. Truong, Universite Paris-Sud, Orsay, France. *Electron Transfer in Reactions of Positronium in Liquids. V. M. Byakov, V. I. Grafutin, 0. V. Koldaeva, and E. V. Minaichev, I.T.E.P., MOSCOW, Russia.
Theme: Properties of Concentrated Metal-Ammonia Solutions, of Excess Electrons in Glasses, and Electrochemical Phenomena Session I Properties of Concentrated Metal-Solvent Systems, the Metal-Nonmetal Transition. N. F. Mott, University of Cambridge, England. The Influence of Critical Fluctuations of Concentration on the Transport Properties of Metal-Ammonia Solutions. P. Damay and P. Chieux, Lille, France. Species Present in M-NH3 Near the Metal-Insulator Transition. J. V. Acrivos, A. Robertson, A. Thompson, M. P. Klein, and K. Hathaway, San Jose State University, San Jose, California. A Comparative Study of the Concentration Fluctuations in the Metal-Ammonia (Li and Na in Liquid ND3) and the Metal in Molten Salts (K in KBr). P. Chieux (Grenoble),P. Damay (Lille),J. Dupuy (Lyon), and J. F. Jal (Lyon), France. *Disorder Induced Anderson Localization of Excess Electrons in Liquids and Metal-Ammonia: Metal-Ether Solutions via Liquid Phonon Mode Softening. E. Siegel, Queen Mary College, London University, England. Session J Magnetic Relaxation of Localized and Itinerant Electron States in Metal Solutions. P. Edwards, University of Cambridge, England. Temperature Dependence of the Electron Spin-Lattice Relaxation in Lithium-Methylamine Solutions. J. R. Buntaine, M. J. Sienko, Cornel1 University, Ithaca, New York, and P. Edwards, University of Cambridge, England. Session K Excess Electrons in Glasses and Disordered Materials. L. Kevan, Wayne State University, Detroit, Michigan. The Decay Kinetics of Excess Electrons in Crystalline Ice. J. M. Warman, M. P. de Haas, Inter-university Reactor Institute, Delft, The Netherlands, and J. B. Verberne, Biophysics Department, Amsterdam. Mechanism of Formation of Visible-Absorbing Excess Electrons in Crystalline Ice Near 273 K. H. A. Gillis, G. G. Teather, and C. K. Ross, National Research Council, Ottawa, Canada. Photoionization in Nonpolar Liquids Studied by Electric Field Quenching of Recombination Fluorescence and Photoconductivity. J. Bullot, P. Cordier, and M. Gauthier, Universite Paris-Sud, Orsay, France. Symmetry Properties of the Transport Coefficients of Charged Particles in Disordered Materials. J. K. Baird, Oak Ridge National Laboratory, Oak Ridge, Tennessee. Photoionization of Solutes and Conduction Band Edge of Solvents Water and Alcohols. A. Bernas, E. Amouyal, and D. Grand, E.R.A. Orsay, France.
Colloque Weyl V
The Journal of Physical Chemistry,
Vo/,84, No. 10, 1980 1069
Session L Electrochemical and Photoelectrochemical Studies of Excess Electrons in Liquid Ammonia. A. J. Bard, K. Itaya, R. E. Malpas, and T. Teherani, University of Texas at Austin, Austin, Texas. Electrochemical Investigations of Solvated Electrons in Ammonia and Methylamine. W. Gross and U,Schindewolf, Institut fur Physikalische Chemie und Elektrochemie, Universitat Karlsruhe, West Germany. Photocurrents from Semiconductor-Liquid Ammonia Junctions. J. Belloni, G. Van Ameronger, M . Herlem, J. L. Sculfort, and IR. Heindl, Physico-Chimie des Rayonnements, Universite Paris-Sud, Orsay, France. Theme: Electron Transfer Reactions and Positron Annihilation Studies Session M Theory of Electron Transfer Reactions of Solvated Electrons. N. R. Kestner, Louisiana State Uiniversity, Baton Rouge, Louisiana. Linear Free Energy Relationships for the Reactions of Solvated and Dry Electrons in Alcohols. D. Razem and I. Dvornik, “Ruder Boskovic” Institute, Zagreb, Yugoslavia. Do Excess Electrons Migrate from Trap-to-Trap in Low Temperature Molecular Glasses? S. A. Rice, Chemistry Division, AERE, Harwell, England. Session N Positron Annihilation in Metal-Ammonia and Related Solutions. R. N. West, University of East Anglia, England. *The Temperature Dependence of the Positronium Yields and the Positronium Bubble State in SF6 and Neopentane. F. M. Jacobensen, 0. E. Mogensen, and M. Eldrup, Risa, Denmark. Solvi2ted Positron Chemistry: Competitive Positron Reactions with Halides in Water. J. R. Anderson, N,J. Pedersen, P. Christensen, and 0. E. Morgensen, Ris$ National Laboratory, Denmark. Positron Formation Studies of Weakly Bound Electrons on Electron Scavengers. 0. E. Morgensen and B. Levay, Ris$ National Laboratory, Denmark. *Positron Annihilation: Contribution to the Study of Localization Processes in Liquids. J. Ch. Abbe, G. Duplatre, A. G. Maddock, and A. Haessler, Centre de R. Nuclearies, Strasbourg, France. *Papers marked with an asterisk were presented €or discussion at the Colloquium but, €or various reasons, are not included in this symposium issue.
