Author
Makoto Miwa
Bio: Makoto Miwa is an academic researcher from Seikei University. The author has contributed to research in topics: Catalysis & Subtilisin. The author has an hindex of 13, co-authored 47 publications receiving 675 citations.
Papers
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TL;DR: In this article, the Anderson-type molybdopolyanions containing divalent metal ions (Zn, Cu, Co or Mn) as a heteroatom has been reinvestigated.
114 citations
TL;DR: In this paper, the anchoring of a Keggin-type heteropolyacid to a polymeric support and the effect of heterogenization on the HPA catalysis of the oxidation of a primary diol have been studied.
72 citations
TL;DR: In this article, the first and second-lowest energy CT bands of polyoxoanions are qualitatively discussed from the CT interactions among some octahedral units in the UV bands.
57 citations
TL;DR: 12-Heteropolymolybdic acid, a heteropolyacid of Keggin-structure, behaves as an effective catalyst of the Friedel-Crafts-type reactions for aromatic compounds.
Abstract: 12-Heteropolymolybdic acid, a heteropolyacid of Keggin-structure, behaves as an effective catalyst of the Friedel-Crafts-type reactions for aromatic compounds, such as alkylation by benzyl chloride and t-butyl chloride, acylation by acetyl chloride, and sulfonylation by tosyl chloride. The catalyst mainly gives para-substituted products for phenol and anisole. The reactions proceed via carbocation-generation mechanism brought about by the strong Bronsted acid.
45 citations
TL;DR: Tetrabutylammonium salts of 12-heteropolytungstates with central transition metal ions in a tetrahedral oxygen environment, MW12O40 (M=CuII, FeIII, CoII), have been prepared and their spectroscopic data (infrared (IR), near-infrared, UV-vis, and magnetic circular dichroism (MCD)) presented.
Abstract: Tetrabutylammonium salts of 12-heteropolytungstates with central transition metal ions in a tetrahedral oxygen environment, MW12O40 (M=CuII, FeIII, CoII), have been prepared and their spectroscopic data (infrared (IR), near-infrared, UV-vis, and magnetic circular dichroism (MCD)) presented.
42 citations
Cited by
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TL;DR: A review of the use of the technique of solute fluorescence quenching to study the structure and dynamics of proteins and a number of factors are discussed that must be considered in analyzing such data.
1,644 citations
1,477 citations
TL;DR: The catalytic properties of heteropoly compounds have drawn wide attention, owing to the versatility of these compounds as catalysts, which has been demonstrated both by success in large-scale applications and by promising laboratory results as mentioned in this paper.
Abstract: Publisher Summary This chapter describes the essence of the catalytic chemistry of heteropoly compounds in solution and in the solid state. The catalytic properties of heteropoly compounds have drawn wide attention, owing to the versatility of these compounds as catalysts, which has been demonstrated both by successhl large-scale applications and by promising laboratory results. Heteropolyanions are polymeric oxoanions formed by condensation of more than two different mononuclear oxoanions. Heteropolyanions formed from one kind of polyanion are called isopolyanions. Acidic elements such as Mo, W, V, Nb and Ta, which are present as oxoanions in aqueous solution, tend to polymerize by dehydration at low pH, forming polyanions and water.Heteropoly catalysts can be applied in various ways. They are used as acid as well as oxidation catalysts. They are used in various phases, as homogeneous liquids, in two-phase liquids (in phase-transfer catalysis), and in liquid-solid and in gas-solid combinations, etc.
1,047 citations
TL;DR: It is shown that it is possible to construct complex chemical systems based upon polyoxometalates, manipulating the templating/self Templating rules to exhibit emergent processes from the molecular to the macroscopic scale.
Abstract: Polyoxometalates are clusters of metal-oxide units, comprising a large diversity of nanoscale structures, and have many common building blocks; in fact polyoxometalate clusters are perhaps the largest non-biologically derived molecules structurally characterised. Not only can polyoxometalates have gigantic nanoscale molecular structures, but they also a have a vast array of physical properties, many of which can be specifically ‘engineered-in’. Here we describe how building block libraries of polyoxometalates can be used to construct systems with important catalytic, electronic, and structural properties. We also show that it is possible to construct complex chemical systems based upon polyoxometalates, manipulating the templating/self templating rules to exhibit emergent processes from the molecular to the macroscopic scale.
724 citations
TL;DR: In this article, a wide variety of HPAs belonging to the so-called Keggin series are the most important for catalysis and they include heteropolyanions (HPANs) which have metal-oxygen octahedra as the basic structural units.
Abstract: Catalysis by heteropoly acids (HPAs) and related compounds is a field of growing importance, attracting increasing attention worldwide, in which many new and exciting developments are taking place in both research and technology [1–111, HPAs are polyoxometalates incorporating anions (heteropolyanions) having metal-oxygen octahedra as the basic structural units [ll-141. Among a wide variety of HPAs those belonging to the so-called Keggin series are the most importance for catalysis. They include heteropolyanions (HPANs)
617 citations