Obituary

Professor Yoshihiko Saito (1920-2014)

[Y. Saito]

A global leader in structural chemistry, known for his studies of atomic arrangement, absolute configuration and electron density using X-ray diffraction, Yoshihiko Saito, Professor Emeritus at the University of Tokyo, died on 12 May 2014 of cerebral infarction at the age of 93.

Saito was born in Osaka on 3 November 1920. He graduated from Osaka U. in 1942 and was a Research Associate there until 1945, when he moved to Osaka City U. as Assistant Professor in 1949. He joined the Institute for Solid State Physics (ISSP) of the U. of Tokyo in 1960 as Professor in Crystallography.

His first years in the ISSP coincided with the vibrant period of rapid advances and innovations in computers and diffractometers to which Saito contributed. He trained young researchers from many universities in the methods and techniques of X-ray diffraction.

After retiring from the U. of Tokyo in March 1981, Saito served as Senior Professor in the Dept. of Chemistry of the newly organized Faculty of Science and Technology of Keio U.

The most important of Saito's achievements include the determination of absolute configuration and studies of electron-density distribution of metal complexes. His determination of the absolute configuration of a six-coordinate cobalt complex using X-ray anomalous scattering at Osaka City U. in 1955 was the world's first successful determination of the absolute configuration of a metal complex molecule. He continued his work in this field at the ISSP. His studies were instrumental in the establishment of empirical laws on the optical rotatory power and absolute configuration of metal complexes.

Saito began investigations of electron density within transition metal complex molecules around 1970. He introduced the automatic single-crystal diffractometer for precise intensity determination, which made it possible to obtain highly detailed data on electron distribution within a crystal. He determined electron configurations in the d orbital from the anisotropy in the three-dimensional distribution of the electrons localized in the vicinity of metal atoms.

Saito recieved the CSJ Award of the Chemical Society of Japan (1967), the Asahi Prize (1976), the Medal with Purple Ribbon (1981), the Second Class Order of the Sacred Treasure (1990) and the Japan Academy Prize (1991). He was president of the Crystallographic Society of Japan (1974-1975), on the editorial board of Acta Crystallographica and editor-in-chief of the Bulletin of the Chemical Society of Japan.

Several years after retiring from Keio U., Alzheimer's disease impaired Saito's walking ability and memory. His long struggle with the affliction sadly ended in confinement to bed. Prof. Saito fulfilled himself as a productive researcher and influential teacher at the right time, with an eventful and successful career. May his soul rest in peace.