Kenichi Fukui

Kenichi Fukui (福井 謙一 Fukui Ken'ichi, October 4, 1918 – January 9, 1998) was a Japanese chemist.^[2]

Kenichi Fukui was co-recipient of the Nobel Prize in Chemistry in 1981 with Roald Hoffmann, for their independent investigations into the mechanisms of chemical reactions. His prize-winning work focused on the role of frontier orbitals in chemical reactions: specifically that molecules share loosely bonded electrons which occupy the frontier orbitals, that is the Highest Occupied Molecular Orbital (HOMO) and the Lowest Unoccupied Molecular Orbital (LUMO).^{[3] [4][5][6][7][8][9]}

Early life

Fukui was the eldest of three sons of Ryokichi Fukui, a foreign trade merchant, and Chie Fukui. He was born in Nara, Japan. In his student days between 1938 and 1941, Fukui's interest was stimulated by quantum mechanics and Erwin Schrödinger's famous equation. He also had developed the belief that a breakthrough in science occurs through the unexpected fusion of remotely related fields.

In an interview with The Chemical Intelligencer Kenichi discusses his path towards chemistry starting from middle school. "The reason for my selection of chemistry is not easy to explain, since chemistry was never my favorite branch in middle school and high school years. Actually, the fact that my respected Fabre had been a genius in chemistry had captured my heart latently, the most decisive occurrence in my education career came when my father asked the advice of Professor Gen-itsu Kita of the Kyoto Imperial University concerning the cause I should take.” On the advice of Kita, a personal friend of the elder Fukui, young Kenichi was directed to the Department of Industrial Chemistry, with which Kita was then affiliated. He also explains that chemistry was difficult to him because it seemed to require memorization to learn it, and that he preferred more logical character in chemistry. He followed the advice a mentor that was well respected by Kenichi himself and never looked back. He also followed in those footsteps by attending Kyoto University in Japan. During that same interview Kenichi also discussed his reason for preferring more theoretical chemistry rather than experimental chemistry. Although he certainly acceded at theoretical science he actually spent much of his early research on experimental. Kenichi had quickly completed more than 100 experimental projects and papers, and he rather enjoyed the experimental phenomena of chemistry. In fact, later on when teaching he would recommend experimental thesis projects for his students to balance them out, theoretical science came more natural to students, but by suggesting or assigning experimental projects his students could understand the concept of both, as all scientist should. Following his graduation from Kyoto Imperial University in 1941, Fukui was engaged in the Army Fuel Laboratory of Japan during World War II. In 1943, he was appointed a lecturer in fuel chemistry at Kyoto Imperial University and began his career as an experimental organic chemist.

Research

Kenichi Fukui Monument at Kyoto University

He was professor of physical chemistry at Kyoto University from 1951 to 1982, president of the Kyoto Institute of Technology between 1982 and 1988, and a member of the International Academy of Quantum Molecular Science and honorary member of the International Academy of Science. He was also director of the Institute for Fundamental Chemistry from 1988 till his death. As well as President of the Chemical Society of Japan from 1983–84, receiving multiple awards aside from his Nobel Prize such as; Japan Academy Medal in 1962, Person of Culture Merits in 1981, Imperial Honour of Grand Cordon of the Order of the Rising Sun in 1988, with many other awards not quite as prestigious.

In 1952, Fukui with his young collaborators T. Yonezawa and H. Shingu presented his molecular orbital theory of reactivity in aromatic hydrocarbons, which appeared in the Journal of Chemical Physics. At that time, his concept failed to garner adequate attention among chemists. Fukui observed in his Nobel lecture in 1981 that his original paper 'received a number of controversial comments. This was in a sense understandable, because for lack of my experiential ability, the theoretical foundation for this conspicuous result was obscure or rather improperly given.'

The frontier orbitals concept came to be recognized following the 1965 publication by Robert B. Woodward and Roald Hoffmann of the Woodward-Hoffmann stereoselection rules, which could predict the reaction rates between two reactants. These rules, depicted in diagrams, explain why some pairs react easily while other pairs do not. The basis for these rules lies in the symmetry properties of the molecules and especially in the disposition of their electrons. Fukui had acknowledged in his Nobel lecture that, 'It is only after the remarkable appearance of the brilliant work by Woodward and Hoffmann that I have become fully aware that not only the density distribution but also the nodal property of the particular orbitals have significance in such a wide variety of chemical reactions.'

What has been striking in Fukui's significant contributions is that he developed his ideas before chemists had access to large computers for modeling. Apart from exploring the theory of chemical reactions, Fukui's contributions to chemistry also include the statistical theory of gelation, organic synthesis by inorganic salts and polymerization kinetics.

In an interview to New Scientist magazine in 1985, Fukui had been highly critical on the practices adopted in Japanese universities and industries to foster science. He noted, "Japanese universities have a chair system that is a fixed hierarchy. This has its merits when trying to work as a laboratory on one theme. But if you want to do original work you must start young, and young people are limited by the chair system. Even if students cannot become assistant professors at an early age they should be encouraged to do original work." Fukui also admonished Japanese industrial research stating, "Industry is more likely to put its research effort into its daily business. It is very difficult for it to become involved in pure chemistry. There is a need to encourage long-range research, even if we don't know its goal and if its application is unknown." In another interview with The Chemical Intelligencer he further elaborates on his criticism by saying, "As is known worldwide, Japan has tried to catch up with the western countries since the beginning of this century by importing science from them." Japan is, in a sense, relatively new to fundamental science as a part of its society and the lack of originality ability, and funding which the western countries have more advantages in hurt the country in fundamental science. Although, he has also stated that it is improving in Japan, especially funding for fundamental science as it has seen a steady increase for years.

Awards and honors

Fukui was awarded the Nobel Prize for his realization that a good approximation for reactivity could be found by looking at the frontier orbitals (HOMO/LUMO). This was based on three main observations of molecular orbital theory as two molecules interact.

1. The occupied orbitals of different molecules repel each other.
2. Positive charges of one molecule attract the negative charges of the other.
3. The occupied orbitals of one molecule and the unoccupied orbitals of the other (especially HOMO and LUMO) interact with each other causing attraction.

From these observations, frontier molecular orbital (FMO) theory simplifies reactivity to interactions between HOMO of one species and the LUMO of the other. This helps to explain the predictions of the Woodward-Hoffman rules for thermal pericyclic reactions, which are summarized in the following statement: "A ground-state pericyclic change is symmetry-allowed when the total number of (4q+2)s and (4r)a components is odd"^{[10][11][12][13]}

Fukui was elected a Foreign Member of the Royal Society (ForMemRS) in 1989.^[2]

See also

• List of Japanese Nobel laureates
• List of Nobel laureates affiliated with Kyoto University

References

Laureates of the Nobel Prize in Chemistry
1901–1925	1901 Jacobus van 't Hoff 1902 Emil Fischer 1903 Svante Arrhenius 1904 William Ramsay 1905 Adolf von Baeyer 1906 Henri Moissan 1907 Eduard Buchner 1908 Ernest Rutherford 1909 Wilhelm Ostwald 1910 Otto Wallach 1911 Marie Curie 1912 Victor Grignard / Paul Sabatier 1913 Alfred Werner 1914 Theodore Richards 1915 Richard Willstätter 1916 1917 1918 Fritz Haber 1919 1920 Walther Nernst 1921 Frederick Soddy 1922 Francis Aston 1923 Fritz Pregl 1924 1925 Richard Zsigmondy
1926–1950	1926 Theodor Svedberg 1927 Heinrich Wieland 1928 Adolf Windaus 1929 Arthur Harden / Hans von Euler-Chelpin 1930 Hans Fischer 1931 Carl Bosch / Friedrich Bergius 1932 Irving Langmuir 1933 1934 Harold Urey 1935 Frédéric Joliot-Curie / Irène Joliot-Curie 1936 Peter Debye 1937 Norman Haworth / Paul Karrer 1938 Richard Kuhn 1939 Adolf Butenandt / Leopold Ružička 1940 1941 1942 1943 George de Hevesy 1944 Otto Hahn 1945 Artturi Virtanen 1946 James B. Sumner / John Northrop / Wendell Meredith Stanley 1947 Robert Robinson 1948 Arne Tiselius 1949 William Giauque 1950 Otto Diels / Kurt Alder
1951–1975	1951 Edwin McMillan / Glenn T. Seaborg 1952 Archer Martin / Richard Synge 1953 Hermann Staudinger 1954 Linus Pauling 1955 Vincent du Vigneaud 1956 Cyril Hinshelwood / Nikolay Semyonov 1957 Alexander Todd 1958 Frederick Sanger 1959 Jaroslav Heyrovský 1960 Willard Libby 1961 Melvin Calvin 1962 Max Perutz / John Kendrew 1963 Karl Ziegler / Giulio Natta 1964 Dorothy Hodgkin 1965 Robert Woodward 1966 Robert S. Mulliken 1967 Manfred Eigen / Ronald Norrish / George Porter 1968 Lars Onsager 1969 Derek Barton / Odd Hassel 1970 Luis Federico Leloir 1971 Gerhard Herzberg 1972 Christian B. Anfinsen / Stanford Moore / William Stein 1973 Ernst Otto Fischer / Geoffrey Wilkinson 1974 Paul Flory 1975 John Cornforth / Vladimir Prelog
1976–2000	1976 William Lipscomb 1977 Ilya Prigogine 1978 Peter D. Mitchell 1979 Herbert C. Brown / Georg Wittig 1980 Paul Berg / Walter Gilbert / Frederick Sanger 1981 Kenichi Fukui / Roald Hoffmann 1982 Aaron Klug 1983 Henry Taube 1984 Robert Merrifield 1985 Herbert A. Hauptman / Jerome Karle 1986 Dudley R. Herschbach / Yuan T. Lee / John Polanyi 1987 Donald J. Cram / Jean-Marie Lehn / Charles J. Pedersen 1988 Johann Deisenhofer / Robert Huber / Hartmut Michel 1989 Sidney Altman / Thomas Cech 1990 Elias Corey 1991 Richard R. Ernst 1992 Rudolph A. Marcus 1993 Kary Mullis / Michael Smith 1994 George Olah 1995 Paul J. Crutzen / Mario J. Molina / Frank Rowland 1996 Robert Curl / Harold Kroto / Richard Smalley 1997 Paul D. Boyer / John E. Walker / Jens Christian Skou 1998 Walter Kohn / John Pople 1999 Ahmed Zewail 2000 Alan J. Heeger / Alan MacDiarmid / Hideki Shirakawa
2001–present	2001 William Knowles / Ryoji Noyori / K. Barry Sharpless 2002 John B. Fenn / Koichi Tanaka / Kurt Wüthrich 2003 Peter Agre / Roderick MacKinnon 2004 Aaron Ciechanover / Avram Hershko / Irwin Rose 2005 Robert H. Grubbs / Richard R. Schrock / Yves Chauvin 2006 Roger D. Kornberg 2007 Gerhard Ertl 2008 Osamu Shimomura / Martin Chalfie / Roger Y. Tsien 2009 Venkatraman Ramakrishnan / Thomas A. Steitz / Ada E. Yonath 2010 Richard F. Heck / Akira Suzuki / Ei-ichi Negishi 2011 Dan Shechtman 2012 Robert Lefkowitz / Brian Kobilka 2013 Martin Karplus / Michael Levitt / Arieh Warshel 2014 Eric Betzig / Stefan Hell / William E. Moerner 2015 Tomas Lindahl / Paul L. Modrich / Aziz Sancar 2016 Jean-Pierre Sauvage / Fraser Stoddart / Ben Feringa