Motohiro Mizuno

Bio: Motohiro Mizuno is an academic researcher from Kanazawa University. The author has contributed to research in topics: Chemistry & Paramagnetism. The author has an hindex of 20, co-authored 117 publications receiving 2646 citations. Previous affiliations of Motohiro Mizuno include University of Milano-Bicocca & National Institute for Materials Science.

One-dimensional imidazole aggregate in aluminium porous coordination polymers with high proton conductivity.

Abstract: The development of anhydrous proton-conductive materials operating at temperatures above 80 degrees C is a challenge that needs to be met for practical applications. Herein, we propose the new idea of encapsulation of a proton-carrier molecule--imidazole in this work--in aluminium porous coordination polymers for the creation of a hybridized proton conductor under anhydrous conditions. Tuning of the host-guest interaction can generate a good proton-conducting path at temperatures above 100 degrees C. The dynamics of the adsorbed imidazole strongly affect the conductivity determined by (2)H solid-state NMR. Isotope measurements of conductivity using imidazole-d4 showed that the proton-hopping mechanism was dominant for the conducting path. This work suggests that the combination of guest molecules and a variety of microporous frameworks would afford highly mobile proton carriers in solids and gives an idea for designing a new type of proton conductor, particularly for high-temperature and anhydrous conditions.

Gas detection by structural variations of fluorescent guest molecules in a flexible porous coordination polymer

Abstract: The development of a new methodology for visualizing and detecting gases is imperative for various applications. Here, we report a novel strategy in which gas molecules are detected by signals from a reporter guest that can read out a host structural transformation. A composite between a flexible porous coordination polymer and fluorescent reporter distyrylbenzene (DSB) selectively adsorbed CO₂ over other atmospheric gases. This adsorption induced a host transformation, which was accompanied by conformational variations of the included DSB. This read-out process resulted in a critical change in DSB fluorescence at a specific threshold pressure. The composite shows different fluorescence responses to CO₂ and acetylene, compounds that have similar physicochemical properties. Our system showed, for the first time, that fluorescent molecules can detect gases without any chemical interaction or energy transfer. The host-guest coupled transformations play a pivotal role in converting the gas adsorption events into detectable output signals.

Ultralong Room-Temperature Phosphorescence from Amorphous Polymer Poly(Styrene Sulfonic Acid) in Air in the Dry Solid State

Abstract: Polymer-based room-temperature-phosphorescent (RTP) materials are attractive alternatives to low-molecular-weight organic RTP compounds because they can form self-standing transparent films with high thermal stability. However, their RTP lifetimes in air are usually short (<≈0.4 s). Here, the simple organic amorphous polymer, poly(styrene sulfonic acid) (PSS), exhibits an ultralong RTP lifetime in air when desiccated. The maximum lifetime is 1.22 s, which is three times that of previously reported RTP amorphous organic polymers. The lifetime can be controlled by the PSS molecular weight and by the ratio of sulfonic acid groups introduced into the polymer. The dry polymers should enable unprecedented molecular engineering in organic molecule-based optoelectronic devices because of the self-standing and thermal stability attributes.

The Chemistry and Applications of Metal-Organic Frameworks

Abstract: Crystalline metal-organic frameworks (MOFs) are formed by reticular synthesis, which creates strong bonds between inorganic and organic units. Careful selection of MOF constituents can yield crystals of ultrahigh porosity and high thermal and chemical stability. These characteristics allow the interior of MOFs to be chemically altered for use in gas separation, gas storage, and catalysis, among other applications. The precision commonly exercised in their chemical modification and the ability to expand their metrics without changing the underlying topology have not been achieved with other solids. MOFs whose chemical composition and shape of building units can be multiply varied within a particular structure already exist and may lead to materials that offer a synergistic combination of properties.

Engineering Metal Organic Frameworks for Heterogeneous Catalysis

Abstract: 2.2. MOFs with Metal Active Sites 4614 2.2.1. Early Studies 4614 2.2.2. Hydrogenation Reactions 4618 2.2.3. Oxidation of Organic Substrates 4620 2.2.4. CO Oxidation to CO2 4626 2.2.5. Phototocatalysis by MOFs 4627 2.2.6. Carbonyl Cyanosilylation 4630 2.2.7. Hydrodesulfurization 4631 2.2.8. Other Reactions 4632 2.3. MOFs with Reactive Functional Groups 4634 2.4. MOFs as Host Matrices or Nanometric Reaction Cavities 4636

Soft porous crystals

Abstract: Encapsulating guest molecules inside host structures ranging from soft, flexible enzymes to rigid, porous zeolites has led to developments in many areas, including catalysis, sensing and separation. This Review highlights how metal–organic frameworks — materials formed by linking metal centres with organic ligands — can combine softness with regularity to produce dynamic, yet crystalline, structures that may prove useful for a range of applications. The field of host–guest complexation is intensely attractive from diverse perspectives, including materials science, chemistry and biology. The uptake and encapsulation of guest species by host frameworks are being investigated for a wide variety of purposes, including separation and storage using zeolites, and recognition and sensing by enzymes in solution. Here we focus on the concept of the cooperative integration of 'softness' and 'regularity'. Recent developments on porous coordination polymers (or metal–organic frameworks) have provided the inherent properties that combine these features. Such soft porous crystals exhibit dynamic frameworks that are able to respond to external stimuli such as light, electric fields or the presence of particular species, but they are also crystalline and can change their channels reversibly while retaining high regularity. We discuss the relationship between the structures and properties of these materials in view of their practical applications.