Density Functional Theory Studies of Catalytic Sites in Metal- Organic Frameworks

Theoretical methods have become indispensable tools in many fields of chemistry and materials research. Metal-organic frameworks (MOFs) are porous materials; they have been intensively developed due to their diverse properties suitable for a wide range of applications. Theoretical approaches have thus been frequently employed toward the design and characterization of MOFs. We focus here in particular on theoretical studies of single-site catalytic reactions that occur inside the cavities of MOFs. The density functional method (DFT) has been the main approach used for such studies. We briefly review the uses of DFT to examine the catalytic reactions in MOFs. We note that DFT methods are versatile and can be made to work for different purposes such as, e.g., force-field development for molecular simulations. We shall, however, cover this field only very succinctly to put it into context with our main topic

Electronic circular dichroism spectrum of uridine studied by the SAC-CI method

Abstract Symmetry-adapted cluster-configuration interaction (SAC-CI) method was applied to calculate electronic CD spectrum of a nucleoside, uridine. Based on the theoretical CD and absorption spectra, the observed peaks in the experimental spectra were assigned. The excited states of uracil, the base part of uridine, were also calculated for comparison. The origin of CD rotational strength for the lowlying p-p * and n-p * excited states was analyzed. Rotational strength of the p-p * transition depends on the magnitude of the electric and magnetic transition dipole moments, while that of the n-p * originates from the angle between the two transition moments

Exploration of glassy state in Prussian blue analogues

Prussian blue analogues (PBAs) are archetypes of microporous coordination polymers/metal–organic frameworks whose versatile composition allows for diverse functionalities. However, developments in PBAs have centred solely on their crystalline state, and the glassy state of PBAs has not been explored. Here we describe the preparation of the glassy state of PBAs via a mechanically induced crystal-to-glass transformation and explore their properties. The preservation of short-range metal–ligand–metal connectivity is confirmed, enabling the framework-based functionality and semiconductivity in the glass. The transformation also generates unconventional CN(−) vacancies, followed by the reduction of metal sites. This leads to significant porosity enhancement in recrystallised PBA, enabled by further accessibility of isolated micropores. Finally, mechanical stability under stress for successful vitrification is correlated to defect contents and interstitial water. Our results demonstrate how mechanochemistry provides opportunities to explore glassy states of molecular framework materials in which the stable liquid state is absent

タコウセイ ハイイ コウブンシ ノ ブツリ カガクテキ セイシツ ニ カンスル ケンキュウ

京都大学0048新制・課程博士博士(工学)甲第15007号工博第3181号新制||工||1478(附属図書館)27457UT51-2009-R731京都大学大学院工学研究科合成・生物化学専攻(主査)教授 北川 進, 教授 杉野目 道紀, 教授 濵地 格学位規則第4条第1項該当Doctor of Philosophy (Engineering)Kyoto UniversityDFA

TOPICAL REVIEW: Chemistry and application of flexible porous coordination polymers

Porous coordination polymers (PCPs), which are microporous materials, have been given much attention from both scientific and commercial aspects regarding their application to gas storage, gas separation and catalytic reaction because of the regularity of their pore shape and pore size, accompanied with the functionality. Moreover, in recent years, flexible PCPs, which are structurally transformable depending upon external stimuli, have been attractive because they provide unique properties, dissimilar to those of zeolites. In this review, the chemistry and application of flexible crystalline PCPs are summarized and discussed

Chemistry and application of flexible porous coordination polymers

Porous coordination polymers (PCPs), which are microporous materials, have been given much attention from both scientific and commercial aspects regarding their application to gas storage, gas separation and catalytic reaction because of the regularity of their pore shape and pore size, accompanied with the functionality. Moreover, in recent years, flexible PCPs, which are structurally transformable depending upon external stimuli, have been attractive because they provide unique properties, dissimilar to those of zeolites. In this review, the chemistry and application of flexible crystalline PCPs are summarized and discussed