Metal-nanocluster science and technology: my personal history and outlook.

Metal nanoclusters (NCs) are one of the leading targets in research of nanoscale materials, and elucidation of their properties (science) and development of control techniques (technology) have been continuously studied for the past 60 years or so. I have been continuously studying metal NCs since 1995 while changing my own interests, and thereby research topics, according to development of the field and the global situation. Specifically, I started my research on gas-phase metal NCs, and then investigated systematic isolation of glutathionate-protected gold NCs. Thereafter, I worked on development of flexible and precise techniques for controlling ligand-protected metal NCs and creation of highly functional energy and environmental catalysts using ligand-protected metal NCs. This personal account summarizes my previous studies on metal NCs. Through this personal history, I would like to describe my motivation for each previous subject, what type of research I want to perform for each subject in the future, and how I consider the outlook of the field.