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Catalytic activity of iron complex-encapsulated zeolite catalyst ([Fe(bpy)3]2+@Y) for oxidation of benzene increased with increasing the amount of water added to acetonitrile. Maximum value of cata...

Both Ni and alkaline earth metal oxide (MO: CaO, SrO, and BaO)-impregnated SDC powders were prepared as an SOFC anode material. The averaged Ni particle size on SDC was affected by the kind of alkaline earth metal oxide added. The addition of SrO and BaO to Ni/SDC anode enhanced power densities of both H2-SOFC and CH4-SOFC and the addition of CaO lowered them. The maximum power density increased with decreasing the averaged Ni particle size of Ni-MO/SDC anode.

記憶障害で発症し経過中に多幸的言動が見られた右尾状核頭部出血の一例を経験した.症例は54歳男性, 記憶障害を主訴として来院した.神経学的には著明な短期記憶の障害, 失見当識を認める以外は明らかな所見はなかった.頭部CTで右尾状核頭部出搬を認めた.入院中に多幸的な言動も見られ, 記憶障害の軽快と共にこれらの症状も軽快した.123I-SPECTで右側頭葉内側に集積の低下が見られ, 記憶障害, 多幸的言動の出現に尾状核頭部自体の障害, 尾状核と側頭葉の問のdiaschisis様の機序の関与が考えられた.

A novel structural model, [Fe(bpga)(N(3))(OCH(3))] (1) (BPGA: bis(6-pivalamido-2-pyridylmethyl)(carboxy-methyl)amine), for an active site of Fe-containing SOD enzyme with N(3)(-) has been accurately designed and prepared, which has been characterized by X-ray structure analysis and UV-vis, ESR, and IR spectroscopies. Reaction of 1 with acid/base in methanol has shown that the superoxide-accessible site is the N(3)(-)-coordination site in the equatorial plane.

A novel copper(II)[bond]OOH complex with functional ligand that can form a hydrogen bond with the distal oxygen of hydroperoxide has been designed and prepared as a structural/functional model of dopamine beta-hydroxylases, whose spectroscopic characterization and decomposition rates have indicated that the hydroperoxide is activated through the hydrogen-bonding interaction with the distal oxygen.

The (123)I-IMP Graph Plot is a convenient method of analyzing cerebral blood flow without blood sampling. Data acquisition requires 45 minutes after the infusion of (123)I-IMP because the method is matched to the protocol of autoradiography (conventional method). However, we think that those protocols do not have to be matched because those theories are different. Therefore, we contrived a protocol for shortening that time by beginning SPECT data acquisition earlier and shortening the acquisition time compared to the conventional method. We compared count ratios of the decreased area to an area of the healthy side, quantitative values, and results of statistical analysis of the shortened protocol and the conventional method for cases of cerebral infarction and of dementia with Lewy bodies (DLB). Some count ratios of the shortened protocol were inferior to those of the conventional method, but the degrees did not affect the clinical diagnosis. In the other areas and cases also, the differences did not affect the clinical diagnosis. In addition to the results of this study, some previous reports have described that early SPECT images after infusion show the true cerebral blood flow. Therefore, we judged that this shortened protocol can be used as a clinical protocol.

The di- and tetranuclear metal sandwich-type silicotungstates of Cs10[(gamma-SiW10O36)2{Zr(H2O)}2(mu-OH)2] x 18 H2O (Zr2, monoclinic, C2/c (No. 15), a = 25.3315(8) A, b = 22.6699(7) A, c = 18.5533(6) A, beta = 123.9000(12) degrees, V = 8843.3(5) A(3), Z = 4), Cs10[(gamma-SiW10O36)2{Hf(H2O)}2(mu-OH)2] x 17 H2O (Hf2, monoclinic, space group C2/c (No. 15), a = 25.3847(16) A, b = 22.6121(14) A, c = 18.8703(11) A, beta = 124.046(3) degrees, V = 8974.9(9) A(3), Z = 4), Cs8[(gamma-SiW10O36)2{Zr(H2O)}4(mu4-O)(mu-OH)6] x 26 H2O (Zr4, tetragonal, P4(1)2(1)2 (No. 92), a = 12.67370(10) A, c = 61.6213(8) A, V = 9897.78(17) A(3), Z = 4), and Cs8[(gamma-SiW10O36)2{Hf(H2O)}4(mu4-O)(mu-OH)6] x 23 H2O (Hf4, tetragonal, P4(1)2(1)2 (No. 92), a = 12.68130(10) A, c = 61.5483(9) A, V = 9897.91(18) A(3), Z = 4) were obtained as single crystals suitable for X-ray crystallographic analyses by the reaction of a dilacunary gamma-Keggin silicotungstate K8[gamma-SiW10O36] with ZrOCl2 x 8 H2O or HfOCl2 x 8 H2O. These dimeric polyoxometalates consisted of two [gamma-SiW10O36](8-) units sandwiching metal-oxygen clusters such as [M2(mu-OH)2](6+) and [M4(mu4-O)(mu-OH)6](8+) (M = Zr or Hf). The dinuclear zirconium and hafnium complexes Zr2 and Hf2 were isostructural. The equatorially placed two metal atoms in Zr2 and Hf2 were linked by two mu-OH ligands and each metal was bound to four oxygen atoms of two [gamma-SiW10O36](8-) units. The tertanuclear zirconium and hafnium complexes Zr4 and Hf4 were isostructural and consisted of the adamantanoid cages with a tetracoordinated oxygen atom in the middle, [M4(mu4-O)(mu-OH)6](8+) (M = Zr or Hf). Each metal atom in Zr4 and Hf4 was linked by three mu-OH ligands and bound to two oxygen atoms of the [gamma-SiW10O36](8-) unit. The tetra-nuclear zirconium and hafnium complexes showed catalytic activity for the intramolecular cyclization of (+)-citronellal to isopulegols without formation of byproducts resulting from etherification and dehydration. A lacunary silicotungstate [gamma-SiW10O34(H2O)2](4-) was inactive, and the isomer ratio of isopulegols in the presence of MOCl2 x 8 H2O (M = Zr or Hf) were much different from that in the presence of tetranuclear complexes, suggesting that the [M4(mu4-O)(mu-OH)6](8+) core incorporated into the POM frameworks acts as an active site for the present cyclization. On the other hand, the reaction hardly proceeded in the presence of dinuclear zirconium and hafnium complexes under the same conditions. The much less activity is possibly explained by the steric repulsion from the POM frameworks in the dinuclear complexes.

A novel dinuclear zirconium sandwich-type silicotungstate cluster of [(γ-SiW10O36)2Zr2(μ-OH)2]10- (1) was synthesized by the reaction of a divacant lacunary γ-Keggin silicotungstate [γ-SiW10O36]8- with ZrOCl2·8H2O. The anion consisted of two [γ-SiW10O36]8- units sandwiching a diamond Zr2(μ-OH)2 core, and each zirconium atom in 1 was six-coordinated to two μ-OH ligands and four oxygen atoms of two [γ-SiW10O36]8- units. The Zr2(μ-OH)2 core in 1 reacted with methanol to give the corresponding monomethoxo derivative [(γ-SiW10O36)2Zr2(μ-OH)(μ-OCH3)]10- (2).

A mononuclear copper(II)-hydroperoxo species has been generated by the reaction of Cu(I)-H2BPPA complex with dioxygen, which illustrates the enzymatic reaction process of the CuB site in the DbetaM and PHM.

In this review, basic studies on the binding and activation of dioxygen species by copper complexes with originally designed ligands are described as the initial step for development of environment-friendly oxidation catalyst. In order to examine the stability/reactivity of such a mononuclear copper(II) complex, some copper complexes with hydroperoxide ion have been constructed using the ligands that have been prepared on the basis of the active center structures of metalloenzymes, and the effects of (i) hydrogen bond, (ii) hydrophobic sphere, (iii) coordination structure around metal, and (iv) coordinating atoms have been investigated systematically, from the point of view of synthetic, spectroscopic, structural, kinetic, and theoretical chemistries. It has also been found out that the decomposition rate constants and the O–O bond strengths of hydroperoxo copper(II) complexes are strongly correlated.

A novel hydroperoxo-copper(II) complex with a square-planar geometry has been prepared, which has exhibited a higher selectivity and catalytic reactivity for dimethyl sulfide, in contrast to that with a trigonal-bipyramidal one.

CaO catalysts supported on several metal oxides and zeolites were investigated for transesterification of triolein with methanol. Zeolite-supported CaO catalysts showed high catalytic activity for ...

A new μ-η2:η2-peroxo dicopper(II) complex, [CuII2(αSp)2(μ-η2:η2-O2)(Bz-)]SbF6 (αSp = α-isosparteine, Bz- = benzoate) was synthesized by oxygenation of [CuI(αSp)(CH3CN)]SbF6 with Bz- at −80 °C in acetone. X-ray crystallographic analysis of the dark blue crystal revealed that the “bridged butterfly core” is formed by bridging Bz- bound in the axial position. The weaker σ-electron donation of αSp causes the axial coordination of Bz- to stabilize the butterfly-type μ-η2:η2-peroxo dicopper(II) species as an intermediate of stepwise O2-activation to bis(μ-oxo) dicopper(III) species.

Reaction of hydroxozinc(II) complex bearing amino group with CO2 gave carbamate product, whose generation and reaction mechanism have been studied structurally and spectroscopically as a structural...

A novel distorted square-pyramidal N2S3-type Co(III) complex with a vacant site was synthesized as an active center model of nitrile hydratases (NHases) and characterized by UV–vis and 1H NMR spect...

The effects of hydrogen bonding and hydrophobic field on the thermal stabilities of Cu(II)-OOH complexes have been studied using tripodal tetradentate ligands with their functional groups on the basis of UV-vis, ESR, ESI-mass, and resonance Raman spectroscopies.