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Development of selective catalytic reduction (SCR) with alkali tolerance is an essential task to remove air pollution. The previously developed Fe- and H2SO4-induced CeO2exhibited high alkali tolerance while maintaining a high nitrogen oxide conversion (Khan, M.N.; Han, L.: Wang. P.; and Zhang, D. iScience, 2020. 23(6), 101173). In this work, we focused on understanding the influence of induced Fe and H2SO4in the continuous development and improvement of alkali tolerance catalysts. The roles of Fe and H2SO4in preventing alkali poisoning were investigated by using density functional theory calculations. Our results showed that a potassium species hindered the formation of Brønsted acid sites by occupying the lattice oxygen sites on the CeO2surface and inhibited the adsorption of the reductant, NH3. The induced Fe and H2SO4promoted the formation of oxygen vacancies and generated characteristic adsorption sites (SO4/Fe_CeO2_Vo) for the accumulation of multiple potassium atoms. Hence, the synergistic effect of Fe and H2SO4protects NH3adsorption sites on the CeO2surface from potassium poisoning of the catalyst. These findings can also give insight into understanding the similar ability of metal oxide-based catalysts with sulfate ion against alkali poisoning and open new ways in facilitating the tailored design of alkali tolerance catalysts for NH3–SCR.

Dynamic behavior of intermediate adsorbates, such as diffusion, spillover, and reverse spillover, has a strong influence on the catalytic performance in oxide-supported metal catalysts. However, it is challenging to elucidate how the intermediate adsorbates move on the catalyst surface and find active sites to give the corresponding products. In this study, the effect of the dynamic behavior of methoxy intermediate on methanol decomposition on a Pt/TiO2(110) surface has been clarified by combination of scanning tunneling microscopy (STM), temperature-programmed desorption (TPD), and density functional theory (DFT) calculations. The methoxy intermediates were formed by the dissociative adsorption of methanol molecules on Pt nanoparticles at room temperature followed by spillover to the TiO2(110) support surface. TPD results showed that the methoxy intermediates were thermally decomposed at >350 K on the Pt sites to produce CO (dehydrogenation) and CH4(C–O bond scission). A decrease of the Pt nanoparticle density lowered the activity for the decomposition reaction and increased the selectivity toward CH4, which indicates that the reaction is controlled by diffusion and reverse spillover of the methoxy intermediates. Time-lapse STM imaging and DFT calculations revealed that the methoxy intermediates migrate on the five-fold coordinated Ti (Ti5c) sites along the [001] or [11¯0]direction with the aid of hydrogen adatoms bonded to the bridging oxygens (Obr) and can move over the entire surface to seek and find active Pt sites. This work offers an in-depth understanding of the important role of intermediate adsorbate migration in the control of the catalytic performance in oxide-supported metal catalysts.

Inverse molecular design allows the optimization of molecules in chemical space and is promising for accelerating the development of functional molecules and materials. To design realistic molecules, it is necessary to consider geometric stability during optimization. In this work, we introduce an inverse design method that optimizes molecular properties by changing the chemical composition in the equilibrium geometry. The optimization algorithm of our recently developed molecular design method has been modified to allow molecular design for general properties at a low computational cost. The proposed method is based on quantum alchemy and does not require empirical data. We demonstrate the applicability and limitations of the present method in the optimization of the electric dipole moment and atomization energy in small chemical spaces for (BF, CO), (N2, CO), BN-doped benzene derivatives, and BN-doped butane derivatives. It was found that the optimality criteria scheme adopted for updating the molecular species yields faster convergence of the optimization and requires a less computational cost. Moreover, we also investigate and discuss the applicability of quantum alchemy to the electric dipole moment.

The local structure of WO3photocatalyst in the photoexcited metastable state created 150 ps after laser irradiation have been determined by pump-probe L3-edge EXAFS and constrained thorough search analysis. A highly distorted octahedral local structure was found where one of the shortest W-O bonds was further shortened to 1.66 Å while the other five bonds were rather elongated even though theoretical calculations predicted the reverse change. We discuss this contradiction and propose a possible structure for the metastable state.The local structure of WO3photocatalyst in the photoexcited metastable state created 150 ps after laser irradiation has been determined by pump-probe EXAFS and constrained thorough search analysis. A highly distorted octahedral local structure was found, especially one of the shortest W-O was further shortened. We discuss contradiction with theoretical calculation and propose a possible structure for the metastable state.

To elucidate the reaction mechanism and the origin of the enantioselectivity of the asymmetric dehydrative cyclization of allyl alcohol to cyclic ether catalyzed by a Cp-ruthenium complex and a chiral pyridinecarboxylic acid, (R)-X-Naph-PyCOOH, density functional theory (DFT) calculations were performed. According to the DFT calculations, the rate-determining step is the dehydrative σ-allyl formation step with ΔG‡= 18.1 kcal mol–1at 80 °C. This agrees well with the experimental data (ΔG‡= 19.01 kcal mol–1at 80 °C). The DFT result showed that both hydrogen and halogen bonds play a key role in the high enantioselectivity by facilitating the major R,SRu-catalyzed reaction pathway via a σ-allyl Ru intermediate to generate the major (S)-product. In contrast, the reaction is sluggish in the presence of the diastereomeric R,RRucatalyst with an apparent activation energy of 33.1 kcal mol–1; the minor (R)-product is formed via a typical π-allyl Ru intermediate and via a minor pathway for the cyclization step. In addition, the calculated activation Gibbs free energies, 14.4 kcal mol–1for I < 16.8 kcal mol–1for Br < 18.1 kcal mol–1for Cl, reproduced the observed halogen-dependent reactivity with the (R)-X-Naph-PyCOOH ligands. The origin of the halogen trend was clarified by a structural decomposition analysis.

The detailed structures of monomeric ReOxcatalysts supported on the CeO2surface and the reaction mechanism of the deoxydehydration (DODH) reaction were investigated by density functional theory calculations. After examining various ReOxHystructures over CeO2without substrate adsorption, the stable structure under the experimental condition at 400 K was determined to be the ReVIIO2species. The reaction mechanism of DODH was then investigated for the conversion of 1,4-anhydroerythritol to 2,5-dihydrofuran as a model reaction. Through the investigations of several reaction pathways, an oxygen vacancy-assisted mechanism, in which the starting structure is the ReIVO species and the oxidation state of the Re atom changes between +IV and +VI during the reaction, was postulated to be the most plausible pathway, considering the energies of the intermediates and the barrier height for the cleavage of the two C–O bonds.

To understand the influence of incongruent strain on heterogeneous catalysis, the effect of isotropic and anisotropic strains in the catalytic activity of terrace Ru(0001) and stepped Ru(1015) surfaces have been studied for the initial step of the Fischer–Tropsch (FT) reaction. Adsorption–strain relations have been investigated using the d-band model and the novel eigenstress model. The adsorption relation in the reactant state follows both models. The eigenstress model can predict similar qualitative changes in the adsorption energies without the need to calculate the d-band center of the slab. Activation energies also scale according to Brønsted–Evans–Polyani (BEP) relation. Some exemptions included new minimum energy pathways, which do not break the scaling relations but reinforce the mechanochemical effect of producing new chemical pathways with the strain. In addition, in the case of a compressed Ru(1015) surface, reactant adsorption energy does not scale with dissociation activation energy. This is explained by the heightened difference in the reactant interaction energy. These results offer a potential novel route to break the BEP relation in catalysis.

To purchase or authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1532-5415.2008.01676.x Byline: Masafumi Kuzuya (*), Yoshihisa Hirakawa (*), Yusuke Suzuki (*), Mitsunaga Iwata ([dagger]), Hiromi Enoki (*), Jun Hasegawa (*), Akihisa Iguchi (*) Keywords: medication management; mortality; hospitalization; elderly; unmet need Abstract: OBJECTIVES: To clarify the association between unmet medication management need and 3-year mortality and hospitalization for community-dwelling older people with various levels of disabilities. DESIGN: Prospective cohort study (the Nagoya Longitudinal Study for Frail Elderly). SETTING: Community-based. PARTICIPANTS: One thousand seven hundred seventy-two community-dwelling elderly subjects (611 men, 1,161 women). MEASUREMENTS: Data included the clients' demographic characteristics, a rating for basic and instrumental activities of daily living (ADLs), number of prescribed medications and physician-diagnosed chronic diseases, medication adherence, ability to manage medication, and presence or absence of medication assistance. Cox proportional hazard models and the Kaplan-Meier method were used to assess the association between the medication management at baseline and mortality or hospitalization during a 3-year period. RESULTS: Of 1,772 participants, 681 reported no difficulty with self-medication management, and 1,091 experienced difficulty with self-medication. Of participants with difficulty with self-medication management, 929 had medication assistance, and 162 did not. During a 3-year follow up, 424 participants died, and 758 were admitted to hospitals. The baseline data demonstrated that participants not receiving medication assistance were younger and had better ADL status and fewer comorbidities. Multivariate Cox regression models adjusting for potential confounders showed that the lack of assistance in those who needed medication assistance was associated with hospitalization but not mortality during the study period. CONCLUSION: In community-dwelling disabled elderly people, lack of medication assistance in those needing medication support was associated with higher risk of hospitalization. Author Affiliation: (*)Department of Geriatrics, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya, Japan ([dagger])Emergency Department, Nagoya Ekisaikai Hospital, Nakagawa-ku, Nagoya, Japan. Article note: Address correspondence to Masafumi Kuzuya, Department of Geriatrics, Nagoya University Graduate School of Medicine, 65 Tusruma-cho, Showa-ku, Nagoya 466-8550, Japan. E-mail: kuzuya@med.nagoya-u.ac.jp

A study on relationship between reduction in mortality in community-dwelling frail elderly people and day care service use is presented.

We focused on identifying a catalytic active site structure at the atomic level and elucidating the mechanism at the elementary reaction level of liquid-phase organic reactions with a heterogeneous catalyst. In this study, we experimentally and computationally investigated efficient C–H bond activation for the selective aerobic α,β-dehydrogenation of saturated ketones by using a Pd–Au bimetallic nanoparticle catalyst supported on CeO2(Pd/Au/CeO2) as a case study. Detailed characterization of the catalyst with various observation methods revealed that bimetallic nanoparticles formed on the CeO2support with an average size of about 2.5 nm and comprised a Au nanoparticle core and PdO nanospecies dispersed on the core. The formation mechanism of the nanoparticles was clarified through using several CeO2-supported controlled catalysts. Activity tests and detailed characterizations demonstrated that the dehydrogenation activity increased with the coordination numbers of Pd–O species in the presence of Au(0) species. Such experimental evidence suggests that a Pd(II)–(μ-O)–Au(0) structure is the true active site for this reaction. Based on density functional theory calculations using a suitable Pd1O2Au12cluster model with the Pd(II)–(μ-O)–Au(0) structure, we propose a C–H bond activation mechanism via concerted catalysis in which the Pd atom acts as a Lewis acid and the adjacent μ-oxo species acts as a Brønsted base simultaneously. The calculated results reproduced the experimental results for the selective formation of 2-cyclohexen-1-one from cyclohexanone without forming phenol, the regioselectivity of the reaction, the turnover-limiting step, and the activation energy.

A compact inertial electrostatic confinement (IEC) fusion neutron source was developed. Imaging tests using the cylindrical IEC neutron source were conducted with the indirect imaging plate (IP) method using dysprosium foil and an imaging plate. An array of B_4C powder contained in a stainless-steel blade and Cd pins was successfully imaged. To calculate thermal neutron flux of the device, we tested multiple types of IP and IP scanners with the indirect IP method to create a calibration curve, and it was confirmed that dental IP scanners, which are more widely used than industrial ones, can be applied to the indirect IP method.

We report a visible-light-induced copper-catalyzed highly enantioselective umpolung allylic acylation reaction with acylsilanes as acyl anion equivalents. Triplet-quenching experiments and DFT calculations supported our reaction design, which is based on copper-to-acyl metal-to-ligand charge transfer (MLCT) photoexcitation that generates a charge-separated triplet state as a highly reactive intermediate. According to the calculations, the allylic phosphate substrate in the excited state undergoes novel molecular activation into an allylic radical weakly bound to the copper complex. The allyl radical fragment undergoes copper-mediated regio- and stereocontrolled coupling with the acyl group under the influence of the chiral N-heterocyclic carbene ligand.

2,7-Bis(2-phenyl-1H-imidazol-4-yl)fluorenone (BPIFO) was synthesized as a new fluorenone derivative bearing two imidazole moieties, and it exhibited remarkable and reversible changes in photo physical properties through two-step deprotonation with a base and back protonation with an acid in dimethylsulfoxide, which were interpreted by DFT calculations.2,7-Bis(2-phenyl-1H-imidazol-4-yl)fluorenone (BPIFO) was synthesized as a new fluorenone derivative bearing imidazole moieties, and it exhibited remarkable and reversible changes in photo physical properties through two-step deprotonation with a base and back protonation with an acid in dimethylsulfoxide, which were interpreted by DFT calculations.

To authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1532-5415.2010.02837.x Byline: Masafumi Kuzuya (*), Hiromi Enoki (*), Sachiko Izawa (*), Jun Hasegawa (*), Yusuke Suzuki ([dagger]), Akihisa Iguchi ([double dagger]) Author Affiliation: (*)Department of Geriatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan ([dagger])Nagoya University Hospital Department of Outpatient and Home MedicineShowa-ku, Nagoya, Japan ([double dagger])Department of Community Care PhilanthropyFaculty of Medical Welfare Aichi Shukutoku UniversityNagoya, Japan

During the hydrogenation of CO2to methanol over mixed-oxide catalysts, the strong adsorption of CO2and formate poses a barrier for H2dissociation, limiting methanol selectivity and productivity. Here we show that by using Co-containing dual-atom oxide catalysts, the poisoning effect can be countered by separating the site for H2dissociation and the adsorption of intermediates. We synthesized a Co- and In-doped ZrO2catalyst (Co–In–ZrO2) containing atomically dispersed Co and In species. Catalyst characterization showed that Co and In atoms were atomically dispersed and were in proximity to each other owing to a random distribution. During the CO2hydrogenation reaction, the Co atom was responsible for the adsorption of CO2and formate species, while the nearby In atoms promoted the hydrogenation of adsorbed intermediates. The cooperative effect increased the methanol selectivity to 86% over the dual-atom catalyst, and methanol productivity increased 2-fold in comparison to single-atom catalysts. This cooperative effect was extended to Co–Zn and Co–Ga doped ZrO2catalysts. This work presents a different approach to designing mixed-oxide catalysts for CO2hydrogenation based on the preferential adsorption of substrates and intermediates instead of promoting H2dissociation to mitigate the poisonous effects of substrates and intermediates.

Metal nanoclusters (NCs) have unique properties because of their small size, which makes them useful as catalysts in reactions like cross-coupling. Pd-catalyzed oxidative amination, which involves dehydrogenative C–N bond formation, uses Pd complexes as the active species. It is known that the catalytic conditions involve the formation of Pd(0) species from Pd NCs, but the precise role of Pd NCs in the transformations has not been established. In this study, we investigated the characteristic properties of Pd NCs in oxidative amination of 1,3-dienes. The reaction achieved direct amination of commercially accessible 1,3-dienes with secondary aromatic amines, providing a variety of nitrogen containing 1,3-dienes. The compound was applicable to radical polymerization to provide the nitrogen-fabricated 1,3-diene–based polymer, which exhibited a different thermal stability compared to aliphatic nitrogen-fabricated diene polymers. In addition to the synthetic utility, by combining X-ray absorption fine structure and small-angle X-ray scattering analysis, we revealed amines and 1,3-dienes affected metal leaching from the Pd nanoparticles and stabilization of Pd NCs in the catalytic reaction. Additionally, DFT calculation suggested that the catalytic intermediate contained multiple adjacent Pd atoms and was responsible for formation of an σ-allylic intermediate that is difficult to form with the use of Pd complexes. These results could be used to understand the underlying phenomenon in the oxidative coupling reaction and develop Pd NCs-based dehydrogenation.

Quantitative evaluation of the antibacterial activity of conventional antibacterial agents in situ is difficult. In this study, we demonstrated that antibacterial activity can be quantitatively estimated from the photoluminescence intensity of pyrene fluorophores incorporated into tannic acid, a naturally occurring antibacterial agent.Quantitative evaluation of the antibacterial activity of conventional antibacterial agents in situ is difficult. In this study, we demonstrated that antibacterial activity can be quantitatively estimated from the photoluminescence intensity of pyrene fluorophores incorporated into tannic acid, a naturally occurring antibacterial agent.

[Ru(II)Cp((R)-Cl-Naph-PyCOOH)]PF6((R)-1) catalyzes the dehydrative cyclization of (E)-hept-2-ene-1,7-diol (2) to 2-vinyltetrahydro-2H-pyran (3) with a 97:3 S/Renantiomer ratio. Complex (R)-1is in equilibrium between two diastereomers (R,RRu)-1(AR) and (R,SRu)-1(AS). A difference of turn over efficiency between the ASand ARcycles is thought to be the origin of the high enantioselectivity. The ASgives a major enantiomeric product (S)-3, according to the results of detailed mechanistic investigation via i) X-ray crystallographic analysis of related complexes, ii) NMR experiments using allylic alcohol 2, OH-lacking 2-mimic 4, d-labeled (S)-4-1d, enantiomerically enriched hept-6-ene-1,5-diol (6) as branched isomer of 2, and OH-lacking 6-mimic 5, iii) substrate structure/reactivity and selectivity relationships, iv) deuterium-labeling experiment, v) kinetics via calorimetric analysis, and vi) ligand structure/reactivity and selectivity relationships. AScaptures 2via hydrogen and halogen bonds. Oxidative addition in an H2Oinmode leads to a macrocyclic σ-allyl intermediate. Here, an efficient nC(7)OH/π*C(3)=C(2)trans-annular (TA) interaction facilitates an SN2′ nucleophilic addition of OH in an OHTAmanner to furnish (S)-3. Contrary to the AS, ARcannot capture 2using the halogen bond and slowly operates to give (R)-3. A conventional π-allyl-complex-involved mechanism is ruled out by a contradiction in the result of ii) and iii).Mechanism of dehydrative asymmetric allylic cyclization catalyzed by a Cp-ruthenium complex of chiral pyridinecarboxylic acid was investigated. A reaction pathway has been proposed, in which a R,SRu-configrated stereoisomer of σ-allyl complex is smoothly formed through a substrate/catalyst complex assisted by a halogen bond between chloro group with nucleophlic substituent on the substrate to give the major enantiomer of the product.

Recently, mechanical ball milling was applied to chitin depolymerization. The mechanical activation afforded higher selectivity toward glycosidic bond cleavage over amide bond breakage. Hence, the bioactive N-acetylglucosamine (GlcNAc) monomer was preferentially produced over glucosamine. In this regard, the force-dependent mechanochemical activation–deactivation process in the relaxed and pulled GlcNAc dimer undergoing deacetylation and depolymerization reactions was studied. For the relaxed case, the activation energies of the rate-determining steps (RDS) proved that the two reactions could occur simultaneously. Mechanical forces associated with ball milling were approximated with linear pulling and were introduced explicitly in the RDS of both reactions through force-modified potential energy surface (FMPES) formalism. In general, as the applied pulling force increases, the activation energy of the RDS of deacetylation shows no meaningful change, while that of depolymerization decreases. This result is consistent with the selectivity exhibited in the experiment. Energy and structural analyses for the depolymerization showed that the activation can be attributed to a significant change in the glycosidic dihedral at the reactant state. A lone pair of the neighboring pyranose ring O adopts a syn-periplanar conformation relative to the glycosidic bond. This promotes electron donation to the σ*-orbital of the glycosidic bond, leading to activation. Consequently, the Brønsted–Lowry basicity of the glycosidic oxygen also increases, which can facilitate acid catalysis.

Au nanoparticles supported on the manganese oxide octahedral molecular sieve OMS-2 can efficiently catalyze α,β-dehydrogenation of β-N-substituted saturated ketones using O2as the terminal oxidant. However, despite the utility of this reaction, the active sites and the reaction mechanism remain unclear. Here, the reaction mechanism for the Au/OMS-2-catalyzed aerobic α,β-dehydrogenation of 1-methyl-4-piperidone was investigated mainly by using density functional theory (DFT) calculations. From control experiments under various reaction conditions, we found that O2plays an important role in the α,β-dehydrogenation over Au nanoparticles. Thus, we attempted to clarify the mechanism for the α,β-dehydrogenation of 1-methyl-4-piperidone on Au nanoparticle catalysts by DFT calculations using Au cluster models. The reaction was found to cleave the C–Hαand C–Hβbonds in that order. An O2molecule adsorbed on the negatively charged Au cluster caused by charge transfer from OMS-2 was found to be sufficiently activated to abstract the Hαatom in the 1-methyl-4-piperidone substrate. This indirect Hαabstraction by the activated O2was energetically more favorable than direct Hαabstraction by the Au cluster. The subsequent Hβabstraction was found to be promoted by adsorbed oxygen species (i.e., HOO, OH, and O) formed after the Hαabstraction. The reaction mechanism proposed in this study provides general insight into the aerobic C–H bond activation by supported Au catalysts.

Self-assembled multilayer iron(0) nanoparticles (NPs, 6–10 nm), namely, sulfur-modified Au-supported Fe(0) [SAFe(0)], were developed for ligand-free one-pot carbon–carbon/carbon–nitrogen bond-forming reactions. SAFe(0) was successfully prepared using a well-established metal–nanoparticle catalyst preparative protocol by simultaneous in situmetal NP and nanospace organization (PSSO) with 1,4-bis(trimethylsilyl)-1,4-dihydropyrazine (Si-DHP) as a strong reducing agent. SAFe(0) was easy to handle in air and could be recycled with a low iron-leaching rate in reaction cycles.

The ring-opening process was generally considered as the rate-determining step for aromatic volatile organic compound photocatalytic degradation. A sophisticated and intensive degradation pathway is critical to the poor removal efficiency and low mineralization. In the present contribution, we successfully tailored and identified the ring-opening pathway of toluene elimination by electron delocalization in a borocarbonitride photocatalyst. By means of modulation of the dopant coordination configuration and electron geometry in the catalyst, the lone electrons of carbon transform into delocalized counterparts, sequentially elevating the interaction between the toluene molecules and photocatalyst. The aromatic ring of toluene can be attacked directly in the effect of electron delocalization without engendering additional intermediate species, significantly facilitating the removal and mineralization of toluene. This unprecedented route-control strategy alters the aromatic-ring-based reaction behavior from toluene to CO2and paves a way to purify the refractory pollutants from the top design.

A binder plays an important role in stabilizing the electrode structure and improving the cyclic stability of batteries. However, the traditional binders are no longer satisfactory in lithium–sulfur (Li–S) batteries because of their failure in accommodating the large volume changes of sulfur and trapping soluble intermediate polysulfides, thus causing severe capacity decay. In this work, we prepared a multifunctional binder for Li–S batteries by merely modifying the acacia gum (AG), a low-cost biomass polymer, with l-cysteine under mild conditions. Owing to the introduced amino and carboxyl branches by the l-cysteine, the modified AG shows enhanced polysulfide trapping ability and can effectively restrain the shuttling of polysulfides. In addition, the introduction of branches can help form a cross-linked 3D network with better mechanical strength and flexibility for adhering sulfur and accommodating the volume changes of cathode materials. As a result, compared with the normally used polyvinylidene fluoride binder and the unmodified AG binder, the l-cysteine-modified AG binder effectively enhanced the rate capability and cycling stability of the Li–S batteries directly using sulfur as the cathode, showing a promising way to prompt the practical use of Li–S batteries.

Reactions based on transition-metal-catalyzed C–O bond cleavage have attracted much attention as a new synthetic method. Until now, several intermolecular reactions via C–O bond cleavage of aryl ethers, alkenyl ethers, esters, and others have been reported. Here we report an unprecedented C–O bond cleavage of 3-phenoxy acrylic acid derivatives, followed by intramolecular C–O bond formation with alkynes. This reaction gave 2,3-disubstituted benzofurans having useful functional groups—silyl substituents and acrylic acid derivatives—at the 2- and 3-positions, respectively. This report also described theoretical (DFT) insights into the mechanism.

The mechanism of C–H activation of methane by liquid indium, which is the first step of the dehydrogenative conversion of methane to higher hydrocarbons, was investigated using density functional theory calculations. In the first-principle molecular dynamics trajectory at the experimental temperature (1200 K), low-coordinated indium atoms continuously appear on the disordered liquid surface. The C–H cleavage is endothermic on clean surfaces, while the low-coordinated indium atoms reduce the endothermicity significantly. In small indium clusters, which are models of low-coordinated atoms on a surface, the calculated activation energy is much smaller than that on the clean surface. The energy level of the methane C–H σ* orbital is reduced by the interaction with the indium 5pσ orbitals. In2shows the lowest activation energy and exothermicity in the C–H bond cleavage.

In this work, we tested a setup of X-ray fluorescence (XRF) excited by proton-induced quasi-monochromatic X-rays (proton-induced XRF (PIXRF)) as a low-radiation dose analytical technique for precious cultural heritage samples. The low-dose performance of the PIXRF is experimentally assessed in comparison with the performance of a conventional XRF. For this assessment, we prepared test samples, which simulated original Japanese paintings with copper-bearing pigments. By introducing a figure-of-merit, the PIXRF is found to potentially give a better performance in terms of the radiation dose to the sample and the limit of detection, albeit the degraded multi-elemental analytical capability. PIXRF can be a cost-effective method to perform low dose measurements of precious samples, if introduced in an existing PIXE facility.

A study is conducted to find out the usage of medication by the Japanese older people. The study reveals that the usage of polypharmacy in older Japanese is below expected range.

Reaction mechanisms of hydrosilylation of ketone and alkene with tertiary silane using the Wilkinson-type catalyst were theoretically investigated on the basis of density functional calculations using ωB97XD functional. Previously proposed three mechanisms, the Chalk–Harrod (CH) mechanism, the modified Chalk–Harrod (mCH) mechanism, and the outer-sphere mechanism were examined. Besides, we also found two mechanisms, the alternative CH (aCH) mechanism and the double hydride (DH) mechanism. In the aCH mechanism, a four-coordinate rhodium hydride complex formed through the elimination of R3Si–Cl is a catalytically active species. In the DH mechanism, the active species is a six-coordinate complex with two Rh–H bonds. For the C═O double bond hydrosilylation, the rate-determining steps of the aCH and DH mechanisms are both acetone insertion into the Rh–H bond, and the order of the activation barrier is DH < aCH ≈ CH < mCH. For the C═C double bond hydrosilylation, except for the mCH pathway whose rate-determining step is the hydrosilane addition reaction, the rate-determining steps of the CH, aCH, and DH pathways are Si–C reductive elimination reactions. The order of the energy barrier is DH ≈ mCH < aCH ≈ CH. In the outer-sphere mechanism, no stable intermediate or transition state was found. Consequently, we concluded that the DH mechanism is adopted as the mechanism for the Rh-catalyzed hydrosilylation of the carbonyl group while the mCH or DH mechanism is adopted as the mechanism for alkenes under conditions where their active intermediates are formed. The present result revises a hypothesis that the hydrosilylation of the carbonyl group is in general accomplished by the mCH mechanism. The active species in the DH mechanism has one more extra Rh–H bond compared to that of the other pathways, and its interaction with a silyl group, trans-influence, and small steric effect are the origin of the highly efficient catalytic activity, which was not reported before.

Low-temperature complete oxidation of ethylene by the mesoporous silica-supported Pt catalyst is a forefront technology for food preservation. Public implementations of the Pt catalyst have already begun, and spectroscopy analyses on the catalytic mechanism have been reported. In this study, density functional theory calculations were conducted to clarify the potential energy profile and electronic mechanism of the catalytic reaction. Based on the experimental findings, a reaction pathway was proposed for ethylene oxidation up to CO2formation via the HCHO intermediate. Among several possibilities, a reaction pathway via ethylene dioxide species is energetically plausible for the C–C bond cleavage to generate HCHO. Particular focus was given to the electronic effect of the silica support in the ethylene dioxide route. The reservoir effect, in which the siloxide groups take electrons from the Pt moiety, reduces the activation energy of the C–C bond cleavage step by taking electrons from the σ(C–C) orbital.

It is an intractable issue to improve the low-temperature SO2-tolerant selective catalytic reduction (SCR) of NOxwith NH3because deposited sulfates are difficult to decompose below 300 °C. Herein, we established a low-temperature self-prevention mechanism of mesoporous-TiO2@Fe2O3core–shell composites against sulfate deposition using experiments and density functional theory. The mesoporous TiO2-shell effectively restrained the deposition of FeSO4and NH4HSO4because of weak SO2adsorption and promoted NH4HSO4decomposition on the mesoporous-TiO2. The electron transfer at the Fe2O3(core)-TiO2(shell) interface accelerated the redox cycle, launching the “Fast SCR” reaction, which broadened the low-temperature window. Engineered from the nano- to macro-scale, we achieved one-pot self-installation of mesoporous-TiO2@Fe2O3composites on the self-tailored AlOOH@Al-mesh monoliths. After the thermal treatment, the mesoporous-TiO2@Fe2O3@Al2O3monolith catalyst delivered a broad window of 220–420 °C with NO conversion above 90% and had superior SO2tolerance at 260 °C. The effective heat removal of Al-mesh monolithcatalysts restrained NH3oxidation to NO and N2O while suppressing the decomposition of NH4NO3to N2O, and this led to much better high-temperature activity and N2selectivity. This work supplies a new point for the development of low-temperature SO2-tolerant monolithic SCR catalysts with high N2selectivity, which is of great significance for both academic interests and practical applications.

A triple-layer QM/sQM/MM method was developed for accurately describing the excited-state molecular interactions between chromophore and the molecular environment (Hasegawa, J.; Yanai, K.; Ishimura, K. ChemPhysChem2015, 16, 305). A first-order-interaction space (FOIS) was defined for the interactions between QM and secondary QM (sQM) regions. Moreover, configuration interaction singles (CIS) and its second-order perturbation theory (PT2) calculations were performed within this space. In this study, numerical implementation of this FOISPT2 method significantly reduced the computing time, which realized application to solvatochromic systems, p-coumaric acid in neutral (p-CA) and anionic forms in aqueous solution, retinal Schiff base in methanol (MeOH) solution, and bacteriorhodopsin (bR). The results were consistent with the experimentally observed absorption spectra of the applied systems. The QM/sQM/MM result for the opsin shift was in better agreement to the experimental result than that of the ordinary QM/MM. A decomposition analysis was performed for the excited-state molecular interactions. Among the electronic interactions, charge-transfer (CT) effect, excitonic interaction, and dispersion interaction showed significant large contributions, while the electronic polarization effect presented only minor contribution. Furthermore, the result was analyzed to determine the contributions from each environmental molecule and was interpreted based on the distance of the molecules from the π system in the chromophores.

Atrial natriuretic peptide (ANP) exerts beneficial pharmacological effects in the treatment of various cardiovascular disorders, such as acute congestive heart failure (ADHF). However, the clinical use of ANP is limited to the continuous intravenous infusion owing to its short half-life (2.4 ± 0.7 min). In the present study, we conjugated the glyco-modified ANP with a monoclonal antibody (mAb) or an Fc via chemo-enzymatic glyco-engineering using EndoS D233Q/Q303L. The most potent derivative SG-ANP-Fc conjugate extended the half-life to 14.9 d and the duration of blood pressure lowering effect to over 28 d. This new biologic modality provides an opportunity to develop outpatient therapy after ADHF.

To purchase or authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1532-5415.2007.01512.x Byline: Masafumi Kuzuya (*), Hiromi Enoki (*), Mitsunaga Iwata (*), Jun Hasegawa (*), Yoshihisa Hirakawa (*) Author Affiliation: (*)Department of Geriatrics, Graduate School of Medicine, Nagoya University, Nagoya, Japan

Radical cations show a unique reactivity that is fundamentally different from that of conventional cations and have thus attracted considerable attention as alternative cationic intermediates for novel types of organic reactions. However, asymmetric catalysis to promote enantioselective radical cation reactions remains a major challenge in contemporary organic synthesis. Here, we report that the judicious design of an ion pair consisting of a radical cation and a chiral counteranion induces an excellent level of enantioselectivity. This strategy was applied to enantio-, diastereo-, and regioselective [2 + 2] cycloadditions, as well as enantio-, diastereo-, and regioselective [4 + 2] cycloadditions, by using chiral iron(III) photoredox catalysis. We anticipate that this strategy has the potential to expand the use of several mature chiral anions to develop numerous unprecedented enantioselective radical cation reactions.

Single molecule magnets (SMMs) have been a promising material for next-generation high-density information storage and molecular spintronics. N23–-bridged dilanthanide complexes, {[(Me3Si)2N]2Ln(THF)(μ–η2:η2-N2)(THF)Ln[(Me3Si)2N]2}1–, exhibit high blocking temperatures and have been one of the promising candidates for future application. Rational understanding should be established between the magnetic properties and electronic structure. However, the theoretical study is still challenging due to the complexities in their electronic structures. Here, we theoretically studied the magnetic susceptibility of dilanthanide SMMs based on the state-of-the-art multistate-complete active space self-consistent field and perturbation theory at the second order and restricted active space state interaction with spin–orbit coupling calculations. Temperature dependence of the magnetic susceptibility (χmT–Tcurve) was quantitatively reproduced by the theoretical calculations. The complexities in the electronic states of these dilanthanide complexes originate from significantly strong static electron correlations in the lanthanide 4f and N2π* orbitals and the SOC effect. The temperature dependence of the magnetic susceptibility results from the energy levels and magnetic properties of the low-lying excited state. The χmTvalues below 50 K are dominated by the ground state, while thermal distribution in the low-lying excited state affects the χmTvalues over 50 K. Saturation magnetization at low temperatures was also evaluated, and the result agrees with the experimental observation.

Ceramic matrix composites (CMCs), especially SiC/SiC, have garnered significant attention owing to their remarkable mechanical properties at higher temperatures. For the protection of the substrate from oxidation, the SiC/SiC CMCs inherently require environmental barrier coating (EBC). Because aeroengines must function under a wide range of conditions and environments, the coated CMC must be sufficiently resistant to various damage modes. Among these, the effect of microparticles is one of the limiting factors for the durability and performance of components, particularly when the engine is operated in dusty areas. The main goal of this experimental research is to investigate and determine the surface damage behavior of the coated CMC caused by micro-sand particles. The data were surveyed across a fairly broad range of exposed temperatures and velocities, and covered conditions relevant to advanced hot section designs. In the experiments, silica or alumina sand entrained in the gas stream was jet-blasted from the nozzle and then impinged on the target CMC + EBC coupon. Owing to the broad testing range, the damage mode and extent of damage varied considerably by condition. The obtained data were then reorganized and compared with several previously proposed particle impact models. This is to first understand and obtain a complete picture of all the probable consequences in the expected design and off-design conditions and, second, to determine the validity of, and deviations from the conventional modeling with the present CMC + EBC material, which will be useful in the next component design phase.

Potential energy profiles and electronic structural interpretation of the CO and H2binding reactions to molybdenocene and tungstenocene complexes [MCp2] (M = Mo and W, Cp = cycropentadienyl) were studied using density functional theory calculations and ab initio multiconfigurational electronic structure calculations. Experimentally observed slow H2binding was reasonably explained in terms of the spin-blocking effect. Electronic structural analysis at the minimum-energy intersystem crossing point (MEISCP) revealed that the singly occupied molecular orbital’s π-bonding/σ-antibonding character in the M-CO/H2moiety determines the energy levels of the MEISCP. Analysis of the reaction coordinate showed that the singlet-triplet gap significantly depends on the Cp-M-Cp angle. Therefore, not only the metal–ligand distance but also the Cp-M-Cp angle is an important reaction coordinate to reach the MEISCP, the transition state of H2binding. The role of spin–orbit coupling is also discussed.

We report a carbon(sp2)‐carbon(sp3) bond‐forming cross‐coupling reactions by employing a nano‐size nickel catalyst supported on sulfur‐modified gold (SANi). This transformation demonstrates an efficient synthesis of functionalized aryl compounds, including heterocycles. Notably, the reactions proceeded in good yields with significantly low leaching of nickel from SANi. Moreover, SANi could be recycled several times without significant loss of catalytic activity. Carbon(sp2)‐carbon(sp3) bond‐forming cross‐coupling reactions by employing a nano‐sized nickel catalyst supported on sulfur‐modified gold (SANi) has been reported.

Carbon materials bearing carboxylic acids and phenolic groups efficiently catalyze the hydrolysis of cellulose. In this work, we demonstrate that salicylic acid and phthalic acid show higher activity than other substituted benzoic acids as models of catalytic sites on carbons in the hydrolysis of cellobiose and cellulose. Notably, their turnover frequencies are larger than those of o-chlorobenzoic acid and o-trifluoromethylbenzoic acid, despite their lower acid strength. The high catalytic performance of salicylic acid and phthalic acid is not attributed to a reduction of activation energy but to an increase in the frequency factor. Nuclear magnetic resonance and density functional theory studies indicate that one oxygenated group forms a hydrogen bond with a hydroxyl group in cellobiose, which boosts the probability of attack of the neighboring carboxylic acid on the glycosidic bond. The computation also predicts a hydrolysis mechanism including an SN1 reaction with anomeric inversion, which reasonably accounts for the experimental results in the conversion of cellobiose.

The switching efficiency (SE) of the intramolecular exchange interaction Jbetween the open- and the closed-ring isomers of diarylethenes (DAEs) was investigated using DFT calculations of DAE biradicals with different core structures: DAEs with 3-thienyl, thiophene-S,S-dioxide-3-yl, 2-thienyl, or thiophene-S,S-dioxide-2-yl rings. The SE of DAE with a 3-thienyl ring is calculated to be around 400-fold, which is the largest among the four calculated DAEs. The decay constant β of the exchange interaction Jfor the DAE molecular wires was evaluated by calculating Jfor biradicals with different lengths of wires. For the wires of the closed-ring isomers of DAE with 3-thienyl- and thiophene-S,S-dioxide-3-yl rings, which are supposed to take a quinoid structure, allyl nitronyl nitroxide radical was successfully employed. The calculated β values showed a significant difference between the open- and the closed-ring isomers, and this difference of β is considered to be the origin of photoswitching of J. The difference of β upon isomerization, Δβ, is in good agreement with SE, and the largest Δβ was obtained for the DAE with a 3-thienyl ring. We can understand the switching of Jas the switching of electron tunneling efficiency β between the open- and the closed-ring isomers.

Tetrabutylammonium hydroxide (TBAH) and other quaternary ammonium hydroxides catalyzed the cycloaddition of CO2to epoxides under solvent-free conditions to give cyclic carbonates. When TBAH was exposed to CO2, TBAH was converted into tetrabutylammonium bicarbonate (TBABC), which was a catalytically active species. A D-labeled epoxide and an optically active epoxide were used to study the reaction mechanism, which invoked three plausible pathways. Among them, path A seemed to be predominant; the bicarbonate ion of TBABC attacks the less hindered C atom of the epoxide to generate a ring-opened alkoxide intermediate, which adds to CO2to give a carbonate ion, and the subsequent cyclization yields a cyclic carbonate. Density functional theory (DFT) calculations successfully delineated the potential energy profile for each reaction pathway, among which path A was the lowest-energy pathway in accordance with the experimental results. The tetrabutylammonium (TBA) cation carries the positive charges on the H atoms, but not on the central N atom, and the positively charged H atoms close to the central N atom form an anion-binding site capable of stabilizing various anionic transition states and intermediates.

The decay constant β of π-conjugated molecular wire corresponds to the efficiency of electron tunneling through the molecule. We have calculated β values of intramolecular magnetic exchange interactions by density functional theory for organic bis(nitronyl nitroxide)s that have several molecular wire units, namely, oligo-p-phenylene (OPP), oligophenylene ethynylene (OPE), oligophenylene vinylene (OPV), oligophenylene imine (OPI), bicyclo[1.1.1]pentane oligomer (BCP), β,meso,β-triply fused porphyrin oligomer (TFP), and meso,meso-linked porphyrin oligomer (MLP). For OPP, OPE, OPV, OPI, BCP, TFP, and MLP, β was calculated to be 0.41, 0.25, 0.22, 0.32, 0.77, 0.03, and 0.65 Å–1, respectively. The obtained β values are in good agreement with the experimental value of the molecular tunneling conductance, suggesting similarity of the mechanism between exchange interaction and molecular conductance. This method can be used to estimate the efficiency of electron tunneling through the molecular wire.

2,3-Disubstituted benzofurans with potential for pharmaceutical applications are effectively synthesized by Ni complexes via intramolecular C–O bond activation. The reaction pathway for the full catalytic cycle has been investigated using density functional theory (DFT) calculations. The rate-determining step is the reductive elimination of the product. A key result is that coordination to an alkynyl group of another substrate co-occurs with elimination, which not only improves thermodynamic stability of the product but also determines the reaction pathway of the catalytic cycle. The reductive elimination assisted by the solvent molecules or free ligand results in an endergonic reaction. This result is related to the enhancement of reductive elimination of C–C coupling products by the addition of olefins or alkynes and can be recognized as a self-cocatalytic effect of the substrate. The result adds another viewpoint in the design of catalytic reaction systems with effective catalytic cycles.

Photosensitization of organometallics is a privileged strategy that enables challenging transformations in transition-metal catalysis. However, the usefulness of such photocatalyst-induced energy transfer has remained opaque in iron-catalyzed reactions despite the intriguing prospects of iron catalysis in synthetic chemistry. Herein, we demonstrate the use of iron/photosensitizer-cocatalyzed cycloaddition to synthesize polyarylpyridines and azafluoranthenes, which have been scarcely accessible using the established iron-catalyzed protocols. Mechanistic studies indicate that triplet energy transfer from the photocatalyst to a ferracyclic intermediate facilitates the thermally demanding nitrile insertion and accounts for the distinct reactivity of the hybrid system. This study thus provides the first demonstration of the role of photosensitization in overcoming the limitations of iron catalysis.

Electronic excitations of chromophores in proteins and solutions are associated with the electronic response of the molecular environment. The underlying interactions are important origins of solvatochromism. We performed large-scale configuration interaction singles (CIS) calculations (up to 1000 atoms) for retinal chromophores in proteins and methanol solution, in which one-electron processes (polarization and charge-transfer effects of the environment) are included. The present approach also improved the electrostatic potential, as compared to that described by a molecular mechanics (MM) force field. The CIS results were combined with the symmetry adapted cluster (SAC)-CI result using our own N-layer integrated molecular orbital molecular mechanics (ONIOM) method. As compared to the MM description, the CIS reduces the calculated excitation energy by 0.1–0.3 eV and also improves the relative excitation energies among retinal proteins. We applied our localized molecular orbital (LMO) transformation scheme to analyze the CI wave functions. The result clarified the contributions of the amino acids. In bacteriorhodopsin, Tyr185 contributes intermolecular CT excitations. The radial distribution of amino acids’ contributions to the CI wave function was also analyzed. The results of the analysis are useful not only for understanding the molecular interactions and the role of amino acids in color tuning, but also for providing insight into the structure of the excited-state wave function for the molecular environment. An excitation-energy decomposition analysis also supported the results of the excited-state wave functions.

The donor–acceptor electronic coupling for a bridge-mediated triplet excitation energy transfer (EET) was analyzed to determine the tunneling pathway using intergroup tunneling configuration fluxes. In the singlet EET, the electronic coupling is primarily composed of direct coupling between the donor and acceptor with a secondary contribution from bridge-mediated single-step through-exciton pathways. In contrast, the triplet EET is dominated by superexchange interactions due to the Förster-type interaction becoming forbidden. The triplet EET tunneling pathways are characterized as a sequentially coupled hole and electron transfer (CHET) for both direct and bridge-mediated EETs. This is the first report concerning the difference between the triplet and singlet EETs of the electronic mechanism of bridge-mediated superexchange mechanisms.

Singlet excitation energy transfer (EET) generally occurs via a Förster mechanism and originates from direct electronic coupling between the donor (D) and acceptor (A). However, indirect EET (the so-called superexchange mechanism) can be crucial in some situations. In this study, we have explored the contributions of various linker types, linker lengths, and tunneling energies in D–linker–A molecular systems using quantum chemical methods [Kawatsu et al. J. Phys. Chem. A2011, 115, 10814], obtaining conditions in which the superexchange term emerges. To analyze the results in terms of physical parameters, a model Hamiltonian was developed and found to yield results qualitatively consistent with those from the quantum chemical calculations. In a model compound, the superexchange term can be up to 4 times larger than the direct (Förster) term when the energy of the excited state at a linker unit is close to the tunneling energy and when the interactions between these excited states are strong. The ratio of the indirect term to the direct term is greatest at a certain D–A distance because the number of multistep terms increases and the sizes of multistep indirect terms decay exponentially. Single-step indirect terms, which exhibit a polynomial decay, dominate the indirect term for larger D–A distances. The decay behavior with the distance is very different from that of the McConnell type donor–bridge–acceptor superexchange mechanism proposed for the charge transfer (CT). The result of pathway analysis showed that the exciton states mediate EET. The coupling between the local excited states is driven by the pseudo-Coulombic interaction, even in the superexchange terms.

The self‐assembled structure of alkoxy‐ and N‐alkylcarbamoyl‐substituted zinc–tetraphenylporphyrin at the liquid–highly oriented pyrolytic graphite (HOPG) interface was observed by using scanning tunneling microscopy. The alkoxy porphyrin showed a phase transition from face‐on to edge‐on ordering. The phase transition requires the close‐packed structure of alkoxy porphyrin. The chronological change of the ordering was traced to show the existence of several types of Ostwald ripening including two‐step phase transition from small edge‐on to face‐on and then further to edge‐on orderings. On the other hand, the N‐alkylcarbamoyl porphyrin showed persistent edge‐on ordering, and the ordering was analyzed by the Moiré pattern. Although the edge‐on ordering is observed only in the nonpolar solvent, the orderings have potential applications in the charge and energy transfer.

A detailed description of our second‐generation total synthesis of salinosporamide A is presented. Three contiguous stereocenters in the γ‐lactam structure seen in the natural product were established by stereoselective functionalization of a D‐arabinose scaffold, including an Overman rearrangement to generate a highly congested tetrasubstituted carbon center. One of the definitive reactions in the synthesis was a Lewis acid mediated skeletal rearrangement of a pyranose structure, which enabled the practical conversion of the carbohydrate scaffold to the γ‐lactam structure embedded in salinosporamide A. The use of a benzyl ester as a protective group for a sterically hindered carboxylic acid led to a one‐pot global deprotection at the end of the synthesis.