Obituary: Professor Kenichi Fukui

Kenichi Fukui, chemist: born Nara, Japan 4 October 1918; Lecturer, Kyoto University 1943-45, Assistant Professor 1945-51, Professor 1951-82; Nobel Prize in Chemistry (with Roald Hoffmann) 1981; President, Kyoto Institute of Technology 1982- 88; Director, Institute for Fundamental Chemistry, Kyoto 1988-98; married 1947 Tomoe Horie (one son, one daughter); died Kyoto, Japan 9 January 1998.

The ignorant sometimes say that the Japanese are "just imitators". That is completely false. They are assimilators, often of genius, gifted with truly original creative intellects. The Nobel prize-winning chemist Kenichi Fukui was one such. Yet when it was announced that he had won, in 1981, the Nobel Prize for Chemistry (conjointly with the Polish-born American Roald Hoffmann) only a few colleagues in Japan knew who he was, or what he had achieved.

His work on the theory of chemical reactions had been accomplished quite independently of Hoffmann. Fukui was a modest, retiring man who hated any kind of publicity. He led a quiet life with his family and a few friends, with whom he loved to drink sake and to play music, for he was an excellent singer of French and German songs.

At school in Osaka he was no good at chemistry; he just did not like the subject. His best subject was mathematics, but he was more of a literary scholar, loving books and languages. His teacher told him: "If you like German and maths, you should seek `the way of the chemist'."

Fukui attended Kyoto Imperial University, where he researched synthetic fuel chemistry and worked for the Army Fuel Laboratory from 1941 to 1945. He was appointed a lecturer at Kyoto in 1943, and a full professor from 1951.

He followed in the footsteps of prominent Meiji Period scientists who did original research, like Nagayoshi Nagai, the discoverer of ephedrine, Jokichi Takamine who produced the enzyme preparation Taka-Diastase and was the first to crystallise adrenaline, and the biochemist Umetaro Suzuki who succeeded in the extraction of a substance later known as vitamin B-1. Fukui applied the theory of quantum mechanics to the method of predicting the path of pericyclic organic chemical reactions by calculating the shape and density of the outer electrons cloud. This became known as the "frontier electrical theory" or "frontier orbit theory".

When the news of his Nobel Prize came through, Fukui took it with typical coolness; he had heard a vague rumour, but had ignored it. "I am just another chemist scholar," he said, and seemed to be afraid the honour would bring disorder into his tranquil existence. He was totally without arrogance. His discoveries were seized upon by pharmaceutical companies all over the world, but he went on with his quiet, studious life.

Last April, Kyoto Basic Chemistry Study Laboratory invited Fukui to give a talk to children, and he accepted at once. He talked to them about his own childhood, how he had been fascinated by the mysteries of nature and by the books of the entomologist Jean Henri Fabre. The lives of the insects inspired him to practise exact observation of everyday life in the fields and hedges. So he advised his spellbound audience to be friends with all forms of natural life, and to respect the environment.