Hidefumi Sakamoto

Bio: Hidefumi Sakamoto is an academic researcher from Wakayama University. The author has contributed to research in topics: Crown ether & Moiety. The author has an hindex of 19, co-authored 71 publications receiving 981 citations. Previous affiliations of Hidefumi Sakamoto include Osaka University.

Crown ethers of low symmetry. Spiro crown ethers and 16-crown-5 derivatives

Abstract: Synthese des spirocrowns; evaluation de leur aptitude a la coordination pour l'etude de l'extraction des picrates alcalins. Equilibres d'extraction. 16-crown-5 semble avoir une plus haute selectivite pour Na que 15-crown-5

Molecular Design and Applications of Photochromic Crown Compounds —How Can We Manipulate Metal Ions Photochemically?—

Abstract: The design and applications of photochromic crown compounds are reviewed here. Such compounds exhibit the possibility of distinct photochemical control of metal-ion complexation, based on the ionic interactions of their photoionized photochromic moieties. Crowned spirobenzopyran derivatives which the authors designed, when isomerized to their corresponding merocyanine form by UV irradiation, can afford an additional binding site for a metal ion complexed by their crown ether moiety in a sophisticated way, i.e., by the six-membered chelate formation with the phenolate oxygen atom and the crown-ether-ring nitrogen atom. The crowned spirobenzopyrans, therefore, have their metal-ion complexing properties modified remarkably by photoirradiation, like the crowned spironaphthoxazines that are more photolabile than the spirobenzopyran derivatives. Crowned spirobenzothiopyrans possess an affinity to softer metal ions such as silver ion, which promotes their photoisomerization to the open form. Crowned bis(spiroben...

Spiropyran-based dynamic materials

Abstract: In the past few years, spiropyran has emerged as the molecule-of-choice for the construction of novel dynamic materials. This unique molecular switch undergoes structural isomerisation in response to a variety of orthogonal stimuli, e.g. light, temperature, metal ions, redox potential, and mechanical stress. Incorporation of this switch onto macromolecular supports or inorganic scaffolds allows for the creation of robust dynamic materials. This review discusses the synthesis, switching conditions, and use of dynamic materials in which spiropyran has been attached to the surfaces of polymers, biomacromolecules, inorganic nanoparticles, as well as solid surfaces. The resulting materials show fascinating properties whereby the state of the switch intimately affects a multitude of useful properties of the support. The utility of the spiropyran switch will undoubtedly endow these materials with far-reaching applications in the near future.

Recent progress in fluorescent and colorimetric chemosensors for detection of precious metal ions (silver, gold and platinum ions)

Abstract: Due to the wide range of applications and biological significance, the development of optical probes for silver, gold and platinum ions has been an active research area in the past few years. This tutorial review focuses on the recent contributions concerning the fluorescent or colorimetric sensors for these metal ions, and is organized according to their structural classifications (for Ag+ detection) and unique mechanisms between the sensors and metal ions (for Au3+ and Pt2+ detection).