DISCUSSIONS OF THE FARADAY SOCIETY No. 19, 1955 MICROWAVE AND RADIO- FREQUENCY SPECTROSCOPY THE FARADAY SOCIETY Agents for the Society’s Publications : The Aberdeen University Press Ltd. 6 Upper Kirkgate AberdeenThe Faraday Society reserves the copyright of all Communications published in the ‘‘ Discussions ” PUBLISHED . . . 1955 PRINTED IN GREAT BRITAIN AT THE UNIVERSITY PRESS A B E R D E E NA GENERAL DISCUSSION ON MICROWAVE AND RADIO-FREQUENCY SPECTROSCOPY A GENERAL DISCUSSION on Microwave and Radio-frequency Spectroscopy was held in the Department of Zoology, Cambridge University (by kind permission of the Vice-Chancellor) on the 4th, 5th and 6th April, 1955. The President, Prof, R. G. W. Norrish, F.R.S., was in the Chair at the opening session and about 250 members and visitors were present.b o n g the distinguished overseas members and guests welcomed by the President were the following :- Dr. A. Abragam (France), Mr. J. R. Andersen (Denmark), Dr. and Mrs. W. Anderson (Switzerland), Mr. C. 0. Andersson (Sweden), Dr. J. Arnold (Switzerland), Dr. B. Bak (Denmark), Mr. A. Bassompierre (France), Prof. G. J. Ben6 (Switzerland), Prof. J. Benoit (France), Mr. J. Bonanomi (Switzer- land), Dr. J. C. van den Bosch (Holland), Prof. C. J. F. Botticher (Holland), Monsieur M. Buyle-Bodin (France), Mr. B. P. Combrisson (France), Mr. A. F. Corsniit (Netherlands), Dr. L. V. Coulter (U.S.A.), Prof. B. P. Dailey (U.S.A.), Dr. H. G. Dehmelt (U.S.A.), Dr. G. Del Re (Italy), Dr. P. M. Denis (Switzer- land), Mr. G. Dijkstra (Holland), Moiisieur B.Dreyfus (France), Dr. J. and Madame Duchesne (Belgium), Dr. A. Dymanus (Holland), Dr. G. Erlandsson (Sweden), Prof. Richard Extermann (Switzerland), Dr. P. Favere (Italy), Dr. T. Gaumann (Switzerland), Dr. L. van Gerven (Belgium), Prof. W. Gordy (U.S.A.), Dr. L. Grifono (Italy), Prof. H. S. GLI~OWS~C~ (U.S.A.), Dr. W. D. Gwinn (U.S.A.), Miss Lise Nansen (Denmark), Mr. J. Herrmann (Switzerland), Dr. A. Honig (France), Prof. and Mrs. D. F. Hornig (U.S.A.), Prof. and Mrs. G. B. Kistiakowsky (Cambridge), Dr. M. Kofler (Switzerland), Dr. D. M. Kozyrev (U.S.S.R.), Mr. D. J. Kroon (Holland), Dr. H. Kruger (Germany), Prof. W. N. Lipscomb (U.S.A.), Dr. Ralph Livingston (U.S.A.), Mr. J. H. Lupinski (Holland), Dr. and Madame Lurcat (France), Dr. C. McLean (Holland), D.M. Mjasin-Mickailev (U.S.S.R.), Dr. A. Monfils (Belgium), Monsieur S. Montagner (France), Prof. R. S. Mulliken (London), Dr. G. W. Nederbragt (Holland), Mlle. M. Neuilly (France), Mr. J. A. Nikolaev (U.S.S.R.), Prof. R. A. Ogg, Jr. (U.S.A.), Prof. C. T. O’Konski (Holland), Prof. L. J. Oosterhoff (Holland), Prof. G. E. Pake (U.S.A.), Dr. P. Perio (France), Ir. J. Ph. Poley (Holland), Prof. E. C. Pollard (U.S.A.), Mr. H. Primas (Switzerland), Dr. A. M. Prokhorov (U.S.S.R.), Dr. C .Reid (Canada), Prof. Rogers (U.S.A.), Dr. J. M. van Santen (Holland), Prof. R. L. Scott (U.S.A.), Prof. G. Semerano (Italy), Mr. T. M. Shaw (U.S.A.), Dr. and Mrs. Shoolery (U.S.A.), Dr. M. Skogh (Sweden), Prof. H. G. Thode (Canada), Dr. H. Thurn (Germany), Prof. C. H. Townes (U.S.A.), Mr.W. Versnel (Holland), Dr. J. H. van Waals (Holland), Dr. and Mrs. J. S. van Wieringen (Holland), Mr. E. de Wolf (Belgium), Dr. W. Zeil (Germany). 3A GENERAL DISCUSSION ON MICROWAVE AND RADIO-FREQUENCY SPECTROSCOPY A GENERAL DISCUSSION on Microwave and Radio-frequency Spectroscopy was held in the Department of Zoology, Cambridge University (by kind permission of the Vice-Chancellor) on the 4th, 5th and 6th April, 1955. The President, Prof, R. G. W. Norrish, F.R.S., was in the Chair at the opening session and about 250 members and visitors were present. b o n g the distinguished overseas members and guests welcomed by the President were the following :- Dr. A. Abragam (France), Mr. J. R. Andersen (Denmark), Dr. and Mrs. W. Anderson (Switzerland), Mr.C. 0. Andersson (Sweden), Dr. J. Arnold (Switzerland), Dr. B. Bak (Denmark), Mr. A. Bassompierre (France), Prof. G. J. Ben6 (Switzerland), Prof. J. Benoit (France), Mr. J. Bonanomi (Switzer- land), Dr. J. C. van den Bosch (Holland), Prof. C. J. F. Botticher (Holland), Monsieur M. Buyle-Bodin (France), Mr. B. P. Combrisson (France), Mr. A. F. Corsniit (Netherlands), Dr. L. V. Coulter (U.S.A.), Prof. B. P. Dailey (U.S.A.), Dr. H. G. Dehmelt (U.S.A.), Dr. G. Del Re (Italy), Dr. P. M. Denis (Switzer- land), Mr. G. Dijkstra (Holland), Moiisieur B. Dreyfus (France), Dr. J. and Madame Duchesne (Belgium), Dr. A. Dymanus (Holland), Dr. G. Erlandsson (Sweden), Prof. Richard Extermann (Switzerland), Dr. P. Favere (Italy), Dr. T. Gaumann (Switzerland), Dr. L. van Gerven (Belgium), Prof.W. Gordy (U.S.A.), Dr. L. Grifono (Italy), Prof. H. S. GLI~OWS~C~ (U.S.A.), Dr. W. D. Gwinn (U.S.A.), Miss Lise Nansen (Denmark), Mr. J. Herrmann (Switzerland), Dr. A. Honig (France), Prof. and Mrs. D. F. Hornig (U.S.A.), Prof. and Mrs. G. B. Kistiakowsky (Cambridge), Dr. M. Kofler (Switzerland), Dr. D. M. Kozyrev (U.S.S.R.), Mr. D. J. Kroon (Holland), Dr. H. Kruger (Germany), Prof. W. N. Lipscomb (U.S.A.), Dr. Ralph Livingston (U.S.A.), Mr. J. H. Lupinski (Holland), Dr. and Madame Lurcat (France), Dr. C. McLean (Holland), D. M. Mjasin-Mickailev (U.S.S.R.), Dr. A. Monfils (Belgium), Monsieur S. Montagner (France), Prof. R. S. Mulliken (London), Dr. G. W. Nederbragt (Holland), Mlle. M. Neuilly (France), Mr. J. A. Nikolaev (U.S.S.R.), Prof. R. A.Ogg, Jr. (U.S.A.), Prof. C. T. O’Konski (Holland), Prof. L. J. Oosterhoff (Holland), Prof. G. E. Pake (U.S.A.), Dr. P. Perio (France), Ir. J. Ph. Poley (Holland), Prof. E. C. Pollard (U.S.A.), Mr. H. Primas (Switzerland), Dr. A. M. Prokhorov (U.S.S.R.), Dr. C .Reid (Canada), Prof. Rogers (U.S.A.), Dr. J. M. van Santen (Holland), Prof. R. L. Scott (U.S.A.), Prof. G. Semerano (Italy), Mr. T. M. Shaw (U.S.A.), Dr. and Mrs. Shoolery (U.S.A.), Dr. M. Skogh (Sweden), Prof. H. G. Thode (Canada), Dr. H. Thurn (Germany), Prof. C. H. Townes (U.S.A.), Mr. W. Versnel (Holland), Dr. J. H. van Waals (Holland), Dr. and Mrs. J. S. van Wieringen (Holland), Mr. E. de Wolf (Belgium), Dr. W. Zeil (Germany). 3CONTENTS PAGE General Introduction. By H. C. Longuet-Higgins . I. MICROWAVE SPECTROSCOPY- Introductory Paper : Quadrupole Couplings, Dipole Moments and the Chemical Bond.By Walter Gordy . . Microwave Spectra of Deuterated Furans. Structure of the Furan Molecule. By €3. Bak, L. Hansen and J. Rastrup-Andersen. . The Microwave Spectrum and Structure of Methyl Diacetylene. By . G. A. Heath, L. F. Thomas, E. I. Sherrard and J. Sheridan . Information Pertaining to Molecular Structure, as obtained from the Microwave Spectra of Molecules of the Asymmetric Rotor Type. By W. D. Gwinn . Millimetre Wave Spectrum of Methyl Chloride. By J. T. Cox, T. Gaumann and W. J. Orville Thomas . Connections between Molecular Structure and Certain Magnetic Effects in Molecules. By C. H. Townes, G. C. Dousmanis, R. L. White and R. F. Schwarz . GENERAL DrscussroN.-Dr.B. Bleaney, Prof. C. A. Coulson, Dr. D. J. Millen and Mr. K. M. Sinnott, Prof. C. H. Townes, Dr. W. J. Orville-Thomas . II (a). MICROWAVE ABSORPTION- The Use of Microwaves in the Study of Ionic and Chemical Equilibria at High Temperatures. By T. M. Sugden . The Ions Produced by Traces of Alkaline Earths in Hydrogen Flames. By T. M. Sugden and R. C. Wheeler . The Determination of the Electron Affinity of the Hydroxyl Radical by Microwave Measurements on Flames. By F. M. Page . . The Theory of a Molecular Oscillator and a Molecular Power Amplifier. 5 By N. G. Bassov and A. M. Prokhorov . 9 14 30 38 43 52 56 64 68 76 87 966 CONTENTS TI (b). PARAMAGNETIC RESONANCE- GENERAL DIscuss1oN.-Prof. A. R. Ubbefohde, Dr. T. M. Sugden, Mr. R. P. Bell, Dr. J. N.Agar, Dr. E. Warhurst, Mr. F. M. Page, Prof. F. S. Dainton, Dr. D. J. E. Ingram, Prof. C. H. Townes . Introductory Paper. By J. H. E. Griffiths . Paramagnetism of the Actinide Group. By B. Bleaney . Paramagnetic Resonance of Divalent Manganese Incorporated in Various Lattices. By J. S. van Wieringen . The Magnetic Evidence for Charge Transfer in Octahedral Complexes. By J. Owen . Paramagnetic Resonance in Solutions of Electrolytes. By B. M. Kozyrev . Paramagnetic Resonance in Phthalocyanine, Haemoglobin and other . Organic Derivatives. By D. J. E. Ingram and J. E. Bennett . Paramagnetic Resonance of Free Radicals. By G. E. Pake, S. I. Weissmann and J. Townsend . Paramagnetic Resonance in X-Irradiated PIastics and in Plastic Solu- tions of Free Radicals. By E. E.Schneider . Paramagnetic Resonance Studies of Atomic Hydrogen Produced by Ionizing Radiation. By R. Livingston, H. Zeldes and E. H. Taylor GENERAL DIscussIoN.-Dr. E. E. Schneider, Dr. B. Bleaney, Mr. M. Tinkham, Dr. D. J. E. Ingram, Mr. W. A. Runciman, Dr. P. George, MI-. J. Stanley Griffith, Prof. G. E. Pake, Dr. J. Combrisson and Dr. J. Uebersfeld, Prof. W. Gordy, Prof. F. S. Dainton, Dr. R. Livingston, Dr. H. Zeldes and Dr. E. H. Taylor, Dr. C. R. Extermann, P. Denis and G. Ben&, Prof. C. H. Townes . 111. NUCLEAR MAGNETIC RESONANCE Nuclear Magnetic Resonance Applied to Chemical Problems. By H. S. Gutowsky . Proton Resonance Spectra and the Structure of Diketene. By P. T. Ford and R. E. Richards . A Proton Magnetic Resonance hvestigation of the Structure of Urea, By E.R. Andrew and D. Hyndman . Nuclear Magnetic Resonance in Ammonium Fluoride. By L. E. Drain A Nuclear Resonance Investigation of Polytetrafluoroethylene. By J. A. S. Smith . PAGE 99 106 112 118 27 35 140 147 158 166 173 I87 193 195 200 207CONTENTS 7 PA08 The Relation of High Resolution Nuclear Magnetic Resonance Spectra to Molecular Structures. By J. N. Shoolery . High Resolution of Proton Magnetic Resonance Spectra. By W, A. Anderson and J. T. Arnold . Proton Magnetic Resonance Spectra of Crystalline Borohydrides of Sodium, Potassium and Rubidium. By P. T. Ford and R. E. Richards . Nuclear Magnetic Resonance Spectrum and Molecular Structure of . Aluminium Borohydride. By R. A. Ogg, Jr. and 5. D. Ray. GENERAL DISCuSSIoN.-~rof. H. S. Gutowsky, Dr. N. Sheppard, Prof. W. N. Lipscomb, Dr. Peter Gray, Prof. D. F. Hornig, Dr. Manse1 Davies, Prof. E. R. Andrew, Dr. J. A. S. Smith, Prof. G. E. Pake, Dr. N. Sheppard, Dr. J. N. Shoolery, Mr. R. P. Bell . 1V. QUADRUPOLE SPECTROSCOPY The Interpretation of Quadrupole Spectra. By B. P. Dailey . . An Analysis of the Gradient of the Electric Field in HCN. By A. Bassompierre . Nuclear Quadrupole Resonance in Solids. By H. G. DehmeIt . . GENERAL DISCuSSIoN.-Prof. B. P. DaiIey and Prof. C. H. Tomes, Mr. B. Dreyfus, Dr. H. 0. Pritchard, Prof. C. A. Coulson, Prof. D. F. Hornig, Dr. Lucrat . . 21 5 226 230 239 246 255 260 263 274 Author Index . . 282