Professor emeritus Kenneth W. Hedberg

Journal of

MOLECULAR STRUCTURE ELSEVIER

Journal of Molecular Structure 346 (1995) l-ll

Dedication

Professor Emeritus Kenneth W. Hedberg Professor Kenneth W. Hedberg, known as Ken to his friends, was born in Portland, Oregon on February 2, 1920, the oldest of the two children of Gustave and Ruth Haagsma Hedberg. They were of Swedish descent, but both born in the US. He spent his childhood in Portland, Oregon and Hoquiam, Washington, and finished high school in Medford, Oregon, in 1937. He commenced his university education at Southern Oregon Normal School, a teachers college, in January 1939, but after only two terms he transferred to Oregon State College (now Oregon State University) where he had won a tuition scholarship. After being awarded his B.Sc. degree in 1943, he worked for some years during the war at Shell Development Co., California, where he conducted work on aviation gasoline and penicillin extraction methods. In March 1946 Ken Hedberg moved to California Institute of Technology, where he joined the research team of Linus Pauling and Verner Schomaker. Ken Hedberg was awarded his Ph.D. in 1948 for a thesis on structure determination of molecules in the gas phase, using electron diffraction by the "visual method". He continued his research at Caltech, first for one year as a post-doctoral fellow for Richard Badger, and then as a member of staff at Caltech, doing research together with Verner Schomaker. This period was one of the most "prosperous" in the history of gas electron diffraction, in which, amongst many successful projects, the effects of imaginary scattering factors on the radial distribution curve were understood for the first time. In 1950 Ken applied for a Fulbright Fellowship in order to visit Belgium to study spectroscopy, but (fortunately for the field of gas-phase electron diffraction) his application was received one day too late and therefore not considered. In the meantime at Caltech, he had met, and later visited in Norway, a young Norwegian scientist, Otto Bastiansen. The next year he applied for, and was awarded, Guggenheim and Fulbright Fellowships to work, for one year, at the University of Oslo, Norway, where Professor Odd Hassel and his young co-worker, Otto Bastiansen, had established an electron diffraction laboratory. In Oslo, Ken started working with a young scientist, Lise Smedvik, who had recently received her degree. This cooperation has proven to be very productive, both scientifically and in other ways. Lise Smedvik later became Lise Hedberg, and in addition to becoming his wife, Lise has also been Ken's most important scientific co-worker for over 40 years. Her contribution to Professor Hedberg's research group has been, and still is, remarkable. In 1956, Ken Hedberg started his own research laboratory in structural chemistry at Oregon State University. This laboratory soon became one of the most important in this field and remains so today. It also became an important meeting place for scientists from many countries. Scientists from Japan, Germany, Norway, New Zealand, Great Britain, Hungary, and Australia have, together with scientists from the US, spent prolonged periods of time in Corvallis, Oregon, and a large number of visitors from many countries have spent shorter periods there. Ken has a "visitors book", kept from 1972; up to 1993, this book contained 75 names of visiting scientists from 16 different countries. Professor Kenneth Hedberg is a member of the American Chemical Society and he is a fellow of the American Physical Society, where he has served as secretary-treasurer, vice-chairman and chairman for the Division of Chemical Physics. He is also a fellow of the American Association for the Advancement of Science. Ken Hedberg was a Norwegian Marshall Plan Fellow in 1982, the Odd Hassel Memorial Lecturer at the University of Oslo in 1984, and the Edward A. Guggenheim Memorial Lecturer at the University of Reading, England in 1994. Professor Hedberg received the Sigma Xi Research Award at Oregon State 0022-2860/95/$09.50 © 1995 Elsevier Science B.V. All rights reserved S S D I 0022-2860(94)09009-2

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Dedication~Journal of Molecular Structure 346 (1995) 1-11

University in 1974 and the O.S.U. Alumni Distinguished Professor Award in 1975. He has been Visiting Professor at the University of Oslo, Norway, at the University of Texas at Austin and at the University of Reading, England. He was elected foreign member of the Norwegian Academy of Sciences in 1978 and in 1992 he received an honorary doctorate (Dr. Phil.) from the University of Trondheim, Norway. As indicated earlier, Ken Hedberg's area of research has been determination of gas-phase molecular structures, using the method of electron diffraction. In this field he has published over 130 papers in refereed journals, several chapters in books, and articles in conference proceedings. He has developed, and improved, the experimental equipment and he has also made important theoretical contributions to gas-phase molecular structures. He was one of the first to introduce the use of computers to electron diffraction, and the method he developed for the least squares fitting of theoretical to experimental scattering data is today used by everybody in this field. Since Ken, in 1987, ceased his regular teaching duties, he has been more active than ever in research. New experimental equipment has recently been developed in order to undertake work at very high temperatures. This equipment made it possible, in 1991, to obtain the first complete structure determination of buckminsterfullerene, C60. Ken Hedberg has always chosen research problems which are of fundamental importance. He has been very careful about the conclusions which could be drawn from his experimental results. It has been important for him to point out that since we are working with models, we may very well end up with inaccurate results if we start with a bad model. His lectures about this subject at work-shops and international conferences have been of importance both to the scientists working in this field and to the users of results from gas-phase electron diffraction. One of Ken's main interests for many years has been the field of conformational analysis. He was one of the first to investigate a compound by electron diffraction at several temperatures in order to obtain information about its thermodynamic properties. Studies of conjugated organic molecules, of molecules with possible internal hydrogen bonds, and of the conformational properties of isoelectronic molecules have been some of the many subjects in which Ken Hedberg has made outstanding contributions. It is difficult to know how Ken Hedberg manages to be so very active. Maybe the reason is the large amounts of vitamin C which he, like his colleague Linus Pauling, takes every day. Maybe it is because he plays tennis three to four times a week, or maybe it is Lise who is Ken's secret weapon. I believe it is all of these, combined with a very strong interest in his work and an enthusiasm which must rub off on everybody who gets close to him. We all give him our warmest congratulations on his 75th birthday on February 2, 1995 and we wish him many happy and active years of research in the future.

Kolbjorn Hagen

Refereed research publications 1943

1. Microdetermination of Hydroxyl Content of Organic Compounds. Jack W. Petersen, Kenneth W. Hedberg and Bert E. Christensen, Ind. Eng. Chem. (Anal. Ed.), 15, 225 (1943). 1948

2. An Electron Diffraction Investigation of the Structure of Adamantane. Werner Nowacki and Kenneth W. Hedberg, J. Am. Chem. Soc., 70, 1497 (1948). 1950

3. A Reinvestigation of the Structures of Chlorine Monoxide and Chlorine Dioxide by Electron Diffraction. J.D. Dunitz and Kenneth Hedberg, J. Am. Chem. Soc., 72, 3108 (1950).

Dedication~Journal of Molecular Structure 346 (1995) 1-11

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Mechanism of Oxidation of Leuco Malachite Green by Ceric Sulfate. C. Gardner Swain and Kenneth Hedberg, J. Am. Chem. Soc., 72, 3373 (1950). 5. Separation of Dienes. Daniel B. Luten, Kenneth W. Hedberg and Aldo DeBenedictis, U.S. 2,508,922 (C.A. 44, 7863 f (1950)). .

1951 6. Molecular Structure ofTropolone. E. Heilbronner and Kenneth Hedberg, J. Am. Chem. Soc., 73, 1386

(1951). 7. A Reinvestigation of the Structures of Diborane and Ethane by Electron Diffraction. Kenneth

Hedberg and Verner Schomaker, J. Am. Chem. Soc., 73, 1482 (1951). 8. Infrared Spectra of HOC1 and DOC1. Kenneth Hedberg and Richard M. Badger, J. Chem. Phys., 19,

508 (1951). 9. Infrared Spectra of C120 and C102. Kenneth Hedberg, J. Chem. Phys., 19, 509 (1951).

10. On the Structure of Stable Pentaborane. Kenneth Hedberg, Morton E. Jones and Verner Schomaker, J. Am. Chem. Soc., 73, 3538 (1951). 1952

11. The Structure of Stable Pentaborane. Kenneth Hedberg, Morton E. Jones and Verner Schomaker, Proc. Natl. Acad. Sci. USA, 38, 679 (1952). 12. An Electron Diffraction Investigation of the Structures of the Aminodiboranes (CH3)zNBzH5 and HzNBzH 5. Kenneth Hedberg and A.J. Stosick, J. Am. Chem. Soc., 74, 954 (1952). 13. On the Bonding in Electron Deficient Compounds of Boron. Kenneth Hedberg, J. Am. Chem. Soc., 74, 3486 (1952). 14. A Reinvestigation of the Structure of Difluoromethane by Electron Diffraction. Walter Hamilton and Kenneth Hedberg, J. Am. Chem. Soc., 74, 5529 (1952). 1953

15. On the Structure of Tetraborane. Morton E. Jones, Kenneth Hedberg and Verner Schomaker, J. Am. Chem. Soc., 75, 4116 (1953). 16. Effective Storage Temperatures of Gasoline. Dafiiel B. Luten, Jr., and Kenneth Hedberg, Ind. Eng. Chem., 45, 2098 (1953). 1955

17. An Electron Diffraction Investigation ofDimethyl Selenide. Elihu Goldish, Kenneth Hedberg, Richard E. Marsh and Verner Schomaker, J. Am. Chem. Soc., 77, 2948 (1955). 18. The Molecular Structure of Formyl Fluoride. Morton E. Jones, Kenneth Hedberg and Verner Schomaker, J. Am. Chem. Soc., 77, 5278 (1955). 19. The Molecular Structure of Trisilylamine. Kenneth Hedberg, J. Am. Chem. Soc., 77, 6491 (1955). 1956

20. The Molecular Structure of Cyclobutene, C4H 6. Elihu Goldish, Kenneth Hedberg and Verner Schomaker, J. Am. Chem. Soc., 78, 2714 (1956). 21. Molecular Structure of Gaseous Dinitrogen Tetroxide. Darwin W. Smith and Kenneth Hedberg, J. Chem. Phys., 25, 1282 (1956). 1957

22. Reinvestigation of the Structure of 1,3,5,7-Cyclooctatetraene by Electron Diffraction. O. Bastiansen, Lise Hedberg and Kenneth Hedberg, J. Chem. Phys., 27, 1311 (1957). 1959

23. A Verification of the Molecular Structure of Pentafluorosulfur Hypofluorite (SFsOF) by Electron

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Dedication/Journal of Molecular Structure 346 (1995) 1-11

Diffraction. Roger A. Crawford, Frank B. Dudley and Kenneth Hedberg, J. Am. Chem. Soc., 81, 5287 (1959). 1961

24. The Structure of Arsenobenzene. K. Hedberg, Edward W. Hughes and J. Waser, Acta Crystallogr., 14, 369 (1961). 1962

25. Effect of Temperature on the Structure of Gaseous Molecules. Molecular Structure of PC13 at 300 and 500 K. Kenneth Hedberg and Machio Iwasaki, J. Chem. Phys., 36, 589 (1962). 26. Potential Constants of PC13 from Amplitudes of Vibration and Normal Vibration Frequencies. Machio Iwasaki and Kenneth Hedberg, J. Chem. Phys., 36, 594 (1962). 27. Centrifugal Distortion of Bond Distances and Bond Angles. Machio Iwasaki and Kenneth Hedberg, J. Chem. Phys., 36, 2961 (1962). 28. Effect of Temperature on the Structure of Gaseous Molecules. Kenneth Hedberg and Machio Iwasaki, J. Phys. Soc. Japan, 17, Supp. B-II, 32 (1962). 1963

29. The Molecular Structure of Gaseous Disilyl Sulfide, (SiH3)2S. A. Almenningen, Kenneth Hedberg and Ragnhild Seip, Acta Chem. Scand., 17, 2264 (1963). 30. The Molecular Structure of Disiloxane, (SiH3)20. A. Almenningen, O. Bastiansen, V. Ewing, Kenneth Hedberg and M. Traetteberg, Acta Chem. Scand., 17, 2455 (1963). 1964

31. Least-Squares Refinement of Molecular Structures from Gaseous Electron-Diffraction Sector-Microphotometer Intensity Data. I. Method. Kenneth Hedberg and Machio Iwasaki, Acta Crystallogr., 17, 529 (1964). 32. Least Squares Refinement of Molecular Structures from Gaseous Electron-Diffraction SectorMicrophotometer Intensity Data. II. Adaptation to Automatic Computation. Machio Iwasaki, F.N. Fritsch and Kenneth Hedberg, Acta Crystallogr., 17, 533 (1964). 33. Least Squares Refinement of Molecular Structures from Gaseous Electron-Diffraction Sector Microphotometer Data. III. Refinement ofcyclopropane. O. Bastiansen, F.N. Fritsch and Kenneth Hedberg, Acta Cryst., 17, 538 (1964). 34. Molecular Structure of Gaseous Diboron Tetrachloride, B2C14. Kenneth Hedberg and Robert Ryan, J. Chem. Phys., 41, 2214 (1964). 1966

35. On the Structure of Gaseous XeF 6. Kenneth Hedberg, Steven H. Peterson, Robert R. Ryan and

Bernard Weinstock, J. Chem. Phys., 44, 1726 (1966). 36. The Determination of Vibrational Potential Functions using Mean Amplitudes from Electron Diffraction: Some Recent Results. Kenneth Hedberg, Trans. Am. Cryst. Assoc., 2, 79 (1966). 1968

37. The Molecular Structure of Gaseous 2,3-Dimethylbutadiene. C.F. Aten, Lise Hedberg and Kenneth Hedberg, J. Am. Chem. Soc., 90, 2463 (1968). 1969

38. The Effect of Temperature on the Structure of Gaseous Molecules. II. An Electron-Diffraction Investigation of the Molecular Structures of B2CI4 and SiC14. The Potential Function for Internal Rotation in B2CI4. Robert R. Ryan and Kenneth Hedberg, J. Chem. Phys., 50, 4986 (1969). 39. Molecular Structure of Thionyltetrafluoride, S O F 4. Grete Gundersen and Kenneth Hedberg, J. Chem. Phys., 51, 2500 (1969).

Dedication/Journal of Molecular Structure 346 (1995) 1 11

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1970

40. Molecular Structure of Xenon Tetroxide, XeO 4. Grete Gundersen, Kenneth Hedberg and John L. Huston, J. Chem. Phys., 52, 812 (1970). 41. Molecular Structure of Dicyclopentadienylnickel (CsHs)zNi. Lise Hedberg and Kenneth Hedberg, J. Chem. Phys., 53, 1228 (1970). 42. Electron-Diffraction Investigation of the Molecular Structure of Trifluoramine Oxide, F3NO. Vernon Plato, William D. Hartford and Kenneth Hedberg, J. Chem. Phys., 53, 3488 (1970). 1971

43. An Electron-Diffraction Investigation of Zirconium Tetraborohydride Zr(BH4) 4. Vernon Plato and Kenneth Hedberg, Inorg. Chem., 10, 590 (1971). 44. Electron-Diffraction Investigation of the Molecular Structure of Adamantane. Istvan Hargittai and Kenneth Hedberg, Chem. Commun., 1499 (1971). 45. Conformational Analysis. The Structure, Composition, and Trans-Gauche Energy and Entropy Differences for Ethylene Chlorohydrin as Determined by Electron Diffraction. A. Almenningen, O. Bastiansen, L. Fernholt and Kenneth Hedberg, Acta Chem. Scand., 25, 1946 (1971). 1972 46. On a Reinvestigation of the Structure of Dinitrogen Tetrafluoride, N2F4, by Gaseous Electron

Diffraction. Michael M. Gilbert, Grete Gundersen and Kenneth Hedberg, J. Chem. Phys., 56, 1691 (1972). 47. Reinvestigation of the Structure of Dinitrogen Tetroxide, N204, by Gaseous Electron Diffraction. Bruce W. McClelland, Grete Gundersen, and Kenneth Hedberg, J. Chem. Phys., 56, 4541 (1972). 1973 48. Conformational

49.

50. 51.

52. 53. 54.

55.

Analysis. I. Molecular Structure, Composition, Trans-Gauche Energy and Entropy Differences and Potential Hindering Internal Rotation of Gaseous Oxalyl Chloride as Determined by Electron Diffraction. Kolbjorn Hagen and Kenneth Hedberg, J. Am. Chem. Soc., 95, 1003 (1973). Electron-Diffraction Investigation of the Molecular Structure and Amplitudes of Vibration of Gaseous Thiazyl Chloride, NSC1. Walter C. Emken and Kenneth Hedberg, J. Chem. Phys., 58, 2195 (1973). Reinvestigation of the Molecular Structure of Gaseous p-Benzoquinone by Electron Diffraction. Kolbjorn Hagen and Kenneth Hedberg, J. Chem. Phys., 59, 158 (1973). Conformational Analysis. II. The Molecular Structure, Composition, and Trans-Gauche Energy and Entropy Differences and Potential Hindering Internal Rotation of Gaseous Oxalyl Bromide as Determined by Electron Diffraction. Kolbjorn Hagen and Kenneth Hedberg, J. Am. Chem. Soc., 95, 4796 (1973). Interatomic Distances and rms Amplitudes of Vibration of Gaseous SiF4 from Electron Diffraction. Kolbj~rn Hagen and Kenneth Hedberg, J. Chem. Phys., 59, 1549 (1973). Reinvestigation of the Molecular Structure of Gaseous Beryllium Borohydride BeB2H8 by Electron Diffraction. Grete Gundersen, Lise Hedberg and Kenneth Hedberg, J. Chem. Phys., 59, 3777 (1973). Conformational Analysis. III. Molecular Structure and Composition of 2-Fluoroethanol as Determined by Electron Diffraction. Kolbjorn Hagen and Kenneth Hedberg, J. Am. Chem. Soc., 95, 8263 (1973). Conformational Analysis. IV. Molecular Structure and Composition of Gaseous 2,3-Butanedione as Determined by Electron Diffraction. Kolbj~rn Hagen and Kenneth Hedberg, J. Am. Chem. Soc., 95, 8266 (1973).

1974 56. Molecular Structure of 1,6,6a-Trithia(6a-SW)pentalene. Quang Shen and Kenneth Hedberg, J. Am.

Chem. Soc., 96, 289 (1974).

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Dedication~Journal of Molecular Structure 346 (1995) 1-11

57. An Electron-Diffraction Investigation of the Molecular Structure of Gaseous Methylaminobis(difluorophosphine), CH3N(PF2)2. Erik Hedberg, Lise Hedberg and Kenneth Hedberg, J. Am. Chem. Soc., 96, 4417 (1974). 1975

58. Molecular Structure of Di-Tr-Cyclopentadienylcobalt, (C5H5)2Co, by Gaseous Electron Diffraction. Ann Katherine Hedberg, Lise Hedberg and Kenneth Hedberg, J. Chem. Phys., 63, 1262 (1975). 59. An Electron Diffraction Investigation of the Molecular Structures of Gaseous Trimethylphosphine Oxide, Trimethylphosphine Sulfide, Trimethylarsine Oxide, and Trimethylarsine Sulfide. C.J. Wilkins, Kolbjorn Hagen, Lise Hedberg, Quang Shen and Kenneth Hedberg, J. Am. Chem. Soc., 97, 6352 (1975). 60. An Electron-Diffraction Study of the Molecular Structure of 2-Chlorobenzaldehyde. Lothar Schafer, Svein Samdal and Kenneth Hedberg, J. Mol. Struct., 31, 29 (1975). 1976

61. An Electron-Diffraction Investigation of Gaseous AsBr3. I. Molecular Structure at 373 K and 466 K. II. Quadratic Potential Constants from Amplitudes and Frequencies of Vibration. III. Anharmonicities of Vibration. S. Samdal, D.M. Barnhart and Kenneth Hedberg, J. Mol. Struct., 35, 67 (1976). 1977

62. Gas-Phase Electron Diffraction Study of the Molecular Structure of Tungsten Oxytetrafluoride, WOF 4. Alan Robiette, Kenneth Hedberg and Lise Hedberg, J. Mol. Struct., 37, 105 (1977). 63. Conformational Analysis. 5. Molecular Structure, Composition, Trans-Gauche Energy and Entropy Differences, and Potential Hindering Internal Rotation of Gaseous Formaldazine as Determined by Electron Diffraction. Kolbjorn Hagen, Vladimir Bondybey and Kenneth Hedberg. J. Am. Chem. Soc., 99, 1365 (1977). 64. The Effect of Temperature on the Structure of Gaseous Molecules. 3. Molecular Structure and Barrier to Internal Rotation for Diboron Tetrafluoride. Donald D. Danielson, James V. Patton and Kenneth Hedberg, J. Am. Chem. Soc., 99, 6484 (1977). 65. An Electron Diffraction Investigation of the Molecular Structure of Monochlorodiborane, B2HsC1. Takao Iijima, Lise Hedberg and Kenneth Hedberg, Inorg. Chem., 16, 3230 (1977). 1978

66. Electron Diffraction from Gaseous Tellurium Hexafluoride at 20, 90, and 150°C. Molecular Structure and Three-Atom Scattering. Grete Gundersen, Kenneth Hedberg and Tor G. Strand, J. Chem. Phys., 68, 3548 (1978). 67. The Molecular Structure of Selenonyl Fluoride, SeOzF 2, and Sulfuryl Fluoride, SO2F2, as Determined by Gas Phase Electron Diffraction. Kolbjorn Hagen, Virginia R. Cross and Kenneth Hedberg, J. Mol. Struct., 44, 187 (1978). 68. The Molecular Structure of Gaseous 2-Cyclopenten-1,4-dione as Determined by Electron Diffraction. Kolbj~rn Hagen and Kenneth Hedberg, J. Mol. Struct., 44, 195 (1978). 69. The Molecular Structure of Gaseous Tetrachloro-p-Benzoquinone and Tetrachloro-o-Benzoquinone by Electron Diffraction. Kolbjorn Hagen and Kenneth Hedberg, J. Mol. Struct., 49, 351 (1978). 70. An Electron-Diffraction Investigation of the Molecular Structure of Dichloromaleic Anhydride. Kolbjorn Hagen and Kenneth Hedberg, J. Mol. Struct., 50, 103 (1978). 71. Conformation Analysis. 6. The Molecular Structure of Gaseous Tetrabromoformaldazine as Determined by Electron Diffraction. Kolbjorn Hagen, Vladimir Bondybey and Kenneth Hedberg, J. Am. Chem. Soc., 100, 7178 (1978).

Dedication~Journal of Molecular Structure 346 (1995) 1 11

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1979

72. Nickel Tetracarbonyl, Ni(CO)4. I. Molecular Structure by Gaseous Electron Diffraction. II. Refinement of Quadratic Force Field. Lise Hedberg, Takao Iijima and Kenneth Hedberg, J. Chem. Phys., 70, 3224 (1979). 73. Monomeric Bivalent Group 4B Metal Dialkylamides M[NCMez(CHz)3CMe2] 2 (M = Ge or Sn), and the Structure of a Gaseous Disilylamide, Sn[N(SiMe3)2]2, by Gas-Phase Electron Diffraction. Michael F. Lappert, Philip P. Power, Martin J. Slade, Lise Hedberg, Kenneth Hedberg and Verner Schomaker, J. C. S. Chem. Commun., 369 (1979). 74. The Effect of Temperature on the Structure of Gaseous Molecules. 4. Molecular Structure and Barrier to Internal Rotation for Diboron Tetrabromide. Donald D. Danielson and Kenneth Hedberg, J. Am. Chem. Soc., 101, 3199 (1979). 75. An Electron-Diffraction Investigation of the Molecular Structure of Gaseous 2,3-Butanedione (Biacetyl) at 228 and 525°C. Donald D. Danielson and Kenneth Hedberg, J. Am. Chem. Soc., 101, 3730 (1979). 1980

76. Electron-Diffraction Investigations of the Molecular Structures of c&- and trans-1,2-Dimethyldiborane. Lise Hedberg, Kenneth Hedberg, David A. Kohler, David M. Ritter and Verner Schomaker, J. Am. Chem. Soc., 102, 3430 (1980). 77. Conformational Analysis. 7. 1,2-Difluorethane. An Electron-Diffraction Investigation of the Molecular Structure, Composition, Trans-Gauche Energy and Entropy Differences, and Potential Hindering Internal Rotation. Dwayne Friesen and Kenneth Hedberg, J. Am. Chem. Soc., 102, 3987 (1980). 1981 78. Molecular Structure of Gaseous Cyclobutane-1,2-dione by Electron Diffraction. Kolbjorn Hagen and

Kenneth Hedberg, J. Am. Chem. Soc., 103, 3987 (1980). 1982 79. Molecular Structure and Conformation of c&,cis-l,5-Cyclooctadiene. Kolbjorn Hagen, Lise Hedberg

and Kenneth Hedberg, J. Phys. Chem., 86, 117 (1982). 80. Molecular Structure and Quadratic Force Field of Chromyl Chloride, CRO2C12. C.J. Marsden, Lise

Hedberg and Kenneth Hedberg, Inorg. Chem., 21, 1115 (1982). 81. Thionyl Tetrafluoride. Reanalysis of the Molecular Structure and Resolution of the Multiple Model

Problem. Lise Hedberg and Kenneth Hedberg, J. Phys. Chem., 86, 598 (1982). 82. Molecular Structure of Gaseous Vanadium Pentafluoride, VFs. Kolbjorn Hagen, Michael M. Gilbert,

Lise Hedberg and Kenneth Hedberg, Inorg. Chem., 21, 2690 (1982). 83. Gas-Phase Electron-Diffraction Studies of the Molecular Structures of Tetrachlorosulfidotungsten

(VI), WSC14, and Tetrachloroselenotungsten (VI), WSeC14. Elizabeth M. Page, David A. Rice, Kolbjorn Hagen, Lise Hedberg and Kenneth Hedberg, Inorg. Chem., 21, 3280 (1982). 84. The Molecular Structure of 1,1-Dichlorocyclopropane by Gaseous Electron Diffraction using

Rotational Constants as Constraints and by Ab Initio Gradient Computation. James E. Boggs, Lise Hedberg and Kenneth Hedberg, J. Chem. Phys., 77, 2996 (1982). 85. Molecular Structure and Quadratic Force Field of Chromyl Fluoride, CrO2F2. Richard J. French, Lise Hedberg, Kenneth Hedberg, Gary L. Gard and Bruce M. Johnson, Inorg. Chem., 22, 892 (1983). 86. An Electron-Diffraction Investigation of the Molecular Structure and Thermal Dissociation of Gaseous PC15 at 90°C. Bruce W. McClelland, Lise Hedberg and Kenneth Hedberg, J. Mol. Struct., 99, 309 (1983). 87. Molecular Structure of N205 in the Gas Phase. Large Amplitude Motion in a System of Coupled Rotors. Bruce W. McClelland, Lise Hedberg, Kenneth Hedberg and Kolbjorn Hagen, J. Am. Chem. Soc., 105, 3789 (1983).

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Dedication/Journal of Molecular Structure 346 (1995) 1-I1

1984

88. Structural Consequences of the Jahn-Teller Theorem. Gas-Phase Molecular Structure of CrF 5. E. Jean Jacob, Lise Hedberg, Kenneth Hedberg, Harry Davis and Gary L. Gard, J. Phys. Chem., 88, 1935 (1984). 89. Gas-Phase Electron-Diffraction Study of Tetrafluorosulfidotungsten (VI). David A. Rice, Kolbjorn Hagen, Lise Hedberg and Kenneth Hedberg, Inorg. Chem., 23, 1826 (1984). 90. Molecular Structure of Bis[bis(trimethylsilyl)amido]zinc as Determined by Gas Electron Diffraction. Arne Haaland, Kenneth Hedberg and Philip P. Power, Inorg. Chem., 23, 1972 (1984). 91. Conformational Analysis. 8. Propenoyl Chloride. An Electron-Diffraction Investigation of the Molecular Structure, Composition, Syn-Anti Energy and Entropy Differences, and Potential Hindering Internal Rotation. Kolbjorn Hagen and Kenneth Hedberg, J. Am. Chem. Soc., 106, 6150 (1984). 92. Molecular Structure of Diaminotrifluorophosphorane, PF3(NH2) 2, in the Gas Phase. Colin J. Marsden, Kenneth Hedberg, Jean'ne M. Shreeve and Krishna D. Gupta, Inorg. Chem., 23, 3659 (1984). 1985

93. Conformational Analysis. 9. 2,3-Dichloro-l,3-Butadiene. An Electron-Diffraction Investigation of the Molecular Structure, Composition, and Anti-Gauche Energy and Entropy Differences. Kolbjorn Hagen, Kenneth Hedberg, John Neisess and Grete Gundersen, J. Am. Chem. Soc., 107, 341 (1985). 94. Structure and Bonding in Transition Metal Carbonyls and Nitrosyls. 1. Gas-Phase ElectronDiffraction Investigations of Tetranitrosylchromium, Cr(NO)4, Carbonyltrinitrosylmanganese, MnCO(NO)3, and Dicarbonyldi-nitrosyliron, Fe(CO)2(NO)2. Lise Hedberg, Kenneth Hedberg, Sushil K. Satija and Basil I. Swanson, Inorg. Chem., 106, 6150 (1985). 95. Structure and Bonding in Transition Metal Carbonyls and Nitrosyls. 2. A Gas-Phase Reinvestigation of Tricarbonylnitrosylcobalt, Co(CO)3NO. Kenneth Hedberg, Lise Hedberg, Kolbjorn Hagen, Robert R. Ryan and Llewellyn H. Jones. Inorg. Chem., 23, 3659 (1985). 96. Dichlorotrifluorophosphorane, (PC12F3): Molecular Structure by Gas-Phase Electron Diffraction and Quadratic Force Field. Richard J. French, Kenneth Hedberg, Jean'ne M. Shreeve and Krishna D. Gupta, Inorg. Chem., 24, 2774 (1985). 97. The Molecular Structure of Gaseous [1.1.1]Propellane: An Electron-Diffraction Investigation. Lise Hedberg and Kenneth Hedberg, J. Am. Chem. Soc., 107, 7257 (1985). 98. Structure and Conformations of 4-Chloro-l-Butanol: Electron-Diffraction Evidence for Internal Hydrogen Bonding. Otto Bastiansen, Liv Fernholt, Kenneth Hedberg and Ragnhild Seip, J. Am. Chem. Soc., 107, 7836 (1985). 1986

99. Conformational analysis. 10. Ethane-l,2-dithiol. Electron-Diffraction Investigation of the Molecular Structure, Conformational Composition, and Anti-Gauche Energy and Entropy Differences. Evidence for an Intra-Molecular SH--. S Hydrogen Bond. Sarah L. Barkowski, Lise Hedberg and Kenneth Hedberg. J. Am. Chem. Soc., 108, 6898 (1986). 100. Gas-Phase Molecular Structure of Tetramethyldistibine, (CH3)zSb-Sb(CH3)2. Attila Csfiszfir, Lise Hedberg, Kenneth Hedberg, Edward G. Ludwig, Jr., and Arthur J. Ashe. Organometallics 5, 2257 (1986). 1987

101. Reinvestigation of the Molecular Structure of Gaseous Tetrabromooxo-Tungsten(VI), WOBr4, by Electron Diffraction. Elizabeth M. Page, David A. Rice, Kolbjorn Hagen, Lise Hedberg and Kenneth Hedberg, Inorg. Chem. 26, 467 (1987).

Dedication~Journal of Molecular Structure 346 (1995) 1 11

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102. Gas-Phase Molecular Structure of Ethynylsulfur Pentafluoride, F5SCCH, by Electron Diffraction. Attila G. Csfisz~r, Kenneth Hedberg, Robin J. Terjeson and Gary L. Gard, Inorg. Chem., 26, 955 (1987). 103. Conformational Analysis. 11.2-Aminoethanethiol. An Electron-Diffraction Investigation of the Molecular Structure, Conformational Composition, and Anti-Gauche Energy and Entropy Differences; Evidence for an Intramolecular SHN Hydrogen Bond. Sarah L. Barkowski and Kenneth Hedberg, J. Am. Chem. Soc., 109, 6989 (1987). 104. Structure and Conformations of 1,4-Pentadiene in the Gas Phase: An Electron-Diffraction Investigation. Bruce W. McClelland and Kenneth Hedberg, J. Am. Chem. Soc., 109, 7304 0987). 1988

105. Dioxygen Diftuoride: Electron-Diffraction Investigation of the Molecular Structure in the Gas. Lise Hedberg, Kenneth Hedberg, P.G. Eller and R.R. Ryan, Inorg. Chem., 27, 232 (1988). 106. Molecular Structure of Bromocyclopropane by Gas Electron Diffraction with use of Rotational Constants and by Ab Initio Calculation. Colin J. Marsden, Lise Hedberg and Kenneth Hedberg, J. Phys. Chem., 92, 1766 (1988). 107. Molecular Structure of Gaseous 1,2-Cyclobutene-l,4-dione from Electron Diffraction. Kolbjorn Hagen, Kenneth Hedberg, Bruno Lunelli and Maria Grazia Giorgini, J. Phys. Chem., 92, 4313 (1988). 108. Molecular Structure of Chromium Tetrafluoride in the Gas Phase. Lise Hedberg, Kenneth Hedberg, Gary L. Gard and Joseph O. Udeaja, Acta Chem. Scand., A42, 318 (1988). 109. Structure and Bonding in Transition-Metal Carbonyls and Nitrosyls.3. Molecular Structure of Osmium Pentacarbonyl from Gas-Phase Electron Diffraction. Jinfan Huang, Kenneth Hedberg and Roland Pomeroy, Organometallics, 7, 2049 (1988). 110. Gas-Phase Molecular Structure of Chromium Oxytetrafluoride, CrOF4. Jinfan Huang, Kenneth Hedberg, Jean'ne M. Shreeve and S.P. Mallela. Inorg. Chem., 27, 4633 (1988). 1989

111. Structure of Dicyanoacetylene by Electron Diffraction and Coherent Rotational Raman Spectroscopy. Kirk W. Brown, Joseph W. Nibler, Kenneth Hedberg and Lise Hedberg, J. Phys. Chem., 93, 5679 (1989). 112. Conformational Analysis. 12.2-Chloropropenoyl Chloride. An Electron-Diffraction Investigation of the Molecular Structure, Conformational Composition, Anti-Syn Energy and Entropy Differences, and Potential Hindering Internal Rotation. Kolbjorn Hagen and Kenneth Hedberg, J. Am. Chem. Soc., 111, 6905 (1989). 113. Conformational Analysis. 13. 2-Fluoroethanol. An Investigation of the Molecular Structure and Conformational Composition at 20, 156, and 240°C. Estimate of the Anti-Gauche Energy Difference. Jinfan Huang and Kenneth Hedberg, J. Am. Chem. Soc., 111, 6909 (1989). 1990

114. Conformational Analysis. 14. The Dihaloethanes C1CH2CH2F, BrCHzCH2F, and BrCH2CH2C1. Investigations of the Molecular Structures, Rotameric Compositions, Anti and Gauche Energy and Entropy Differences, and Barriers Hindering Internal Rotation by Gas-Phase Electron Diffraction Augmented by Rotational Constants and Ab Initio Calculation. Jinfan Huang and Kenneth Hedberg, J. Am. Chem. Soc., 112, 2070 (1990). 115. Hexafluorocyclobutene: Gas-Phase Molecular Structure and Quadratic Force Field from an Electron Diffraction and Ab Initio Study. Attila G. Csfiszfir and Kenneth Hedberg, J. Phys. Chem., 94, 3525 (1990).

10

Dedication~Journal of Molecular Structure 346 (1995) 1- 11

116. 1,2-Dichlorotetraftuorocyclobutene: Gas-Phase Molecular Structure and Quadratic Force Field from an Electron-Diffraction and Ab Initio Study. Hanne Thomassen and Kenneth Hedberg, J. Phys. Chem., 94, 4847 (1990). 117. Structure and Bonding in Transition-Metal Carbonyls and Nitrosyls. 4. Molecular Structure of Ruthenium Pentacarbonyl Determined by Gas-Phase Electron Diffraction. Jinfan Juang, Kenneth Hedberg, H.B. Davis and R.K. Pomeroy, Inorg. Chem., 29, 3923 (1990). 118. Distances, Root-Mean-Square Amplitudes of Vibration, and Vibrational Anharmonicity in Carbon Tetrabromide from a Gas-Phase Electron-Diffraction Investigation. Hanne Thomassen and Kenneth Hedberg, J. Mol. Struct., 240, 151 (1990). 1991

119. Bond Lengths and Quadratic Force Field for Cubane. Lise Hedberg, Kenneth Hedberg, Philip E. Eaton, Nereo Nodari and Alan G. Robiette. J. Am. Chem. Soc., 113, 1514 (1991). 120. Gas-Phase Molecular Structure of ((sCsHs)ZrBH4)3: Electron-Diffraction and EHM:O Study. Attila G. Csfiszfir, Lise Hedberg, Kenneth Hedberg, Robert C. Burns, Alex T. Wen and Michael J. McGlinchey, Inorg. Chem., 30, 1371 (1991). 121. Bond Lengths in Free Molecules of Buckminsterfullerene, C60, from Gas-Phase Electron Diffraction. Kenneth Hedberg, Lise Hedberg, Donald S. Bethune, C.A. Brown, H.C. Dorn, Robert D. Johnson and M. de Vries, Science, 254, 410 (1991). 1992

122. Conformational Analysis. 15. 1,3-Dibromotetraftuoroethane and 1,2-Diiodotetrafluoroethane. Electron Diffraction Investigations of the Molecular Structures, Composition, and Anti-Gauche Energy and Entropy Differences. Hanne Thomassen, Svein Samdal and Kenneth Hedberg, J. Am. Chem. Soc., 114, 2810 (1992). 123. Conformational Analysis. 17. Reinvestigation of the Structure and Conformation of Tetrabromoformaldazine (1,1,4,4-Tetrabromo-2,3-diaza-l,3-butadiene) by Gas-Phase Electron Diffraction: Dynamics of Torsion about the N - N bond. Kolbjorn Hagen and Kenneth Hedberg, J. Phys. Chem., 96, 7976 (1992). 124. Conformational Analysis. 18. (I) Molecular Structure and Torsional potential for Tetrachloroformaldazine (1,1,4,4-Tetrachloro-2,3-diaza-l,3-butadiene), a Gas-Phase Electron-Diffraction and Ab Initio Investigation. (II) Update on the Torsional Potential of Formaldazine. Kolbjorn Hagen, Kenneth Hedberg, Paul Rademacher and Marcus Kindermann, J. Phys. Chem., 96, 7978 (1992). 125. Conformational Analysis. 19. 1,2-Dichlorotetrafluoroethane. Molecular Structure, Composition, Anti-Gauche Energy and Entropy Differences, and Quadratic Force Field: An Electron-Diffraction and Ab Initio Study. Hanne Thomassen and Kenneth Hedberg, J. Phys. Chem., 96, 7983 (1992). 126. Molecular Structures of Gaseous Dichloro- and dibromo(dioxo)molybdenum(VI). Are the M o = O Bond Distances and the O = M o = O Bond Angles Similar? Hanne Thomassen and Kenneth Healberg, J. Mol. Struct., 273, 197 (1992). 1993

127. Conformational Analysis. 20. 2-Bromoethanol and 2-Iodoethanol. Structures, Compositions, and Anti-Gauche Energy and Entropy Differences from Electron Diffraction and Structures and Vibrational Wavenumbers from an Ab Initio Calculation. Hanne Thomassen, Svein Samdal and Kenneth Hedberg, J. Phys. Chem., 97, 4004 (1993). 128. The Torsional Potential for Oxalyl Chloride: Are there Two Distinct Conformers? David M. Hassett, Kenneth Hedberg and Colin J. Marsden, J. Phys. Chem., 97, 4670 (1993). 129. Hexafluorobutene: Is the C 3 - C 4 Single Bond Abnormally Long? Lise Hedberg and Kenneth Hedberg, J. Phys. Chem., 97, 10349 (1993).

Dedication~Journal of Molecular Structure 346 (1995) 1 11

11

1994

130. Structure and Conformations of 1,4-Butanediol: Electron-Diffraction Evidence for Internal Hydrogen Bonding. Marit Tr~etteberg and Kenneth Hedberg, J. Am. Chem. Soc., 116, 1382 (1994). 131. Conformational Analysis. 16. Ethylenediamine. An Electron-Diffraction and Ab Initio Investigation of the Molecular Structure, Conformational Composition, Anti-Gauche Energy and Entropy Differences, and Implications for Internal Hydrogen Bonding. M. Rahim Kazerouni, Lise Hedberg and Kenneth Hedberg, J. Am. Chem. Soc., 116, 5279 (1994).

Ph.D. and M.S. students supervised at Oregon State University

Name

Degree

Date awarded

Celia Rose Rockholt David Merle Barnhart Jerome Stanley Blank Robert Reynolds Ryan Bruce Wilson McClelland Walter Charles Emken Michael McCall Gilbert John Allen Neisess Dorothea Joyce Gregory-Allen Robert Chase Demattei Larry Lee Eddy James Roger English Quang Shen Donald Delbert Danielson Robert David Johnson Dwayne Thomas Friesen Sarah Barkowski Richard French Rahim Kazerouni Jinfan Huang

M.S. Ph.D. Ph.D. Ph.D. Ph.D. Ph.D. Ph.D. Ph.D. Ph.D. Ph.D. M.S. M.S. Ph.D. Ph.D. M.S. Ph.D. Ph.D. Ph.D. Ph.D. Ph.D.

1962 1964 1964 1965 1971 1971 1971 1971 1972 1972 1973 1974 1974 1980 1980 1981 1987 1987 1987 1989