Dependence of molecular recognition of fullerene derivative on the adlayer structure of zinc octaethylporphyrin formed on Au(100) surface

Adlayers of ZnOEP were prepared on reconstructed Au(100)-(hex) and unreconstructed Au(100)-(1 x 1) surfaces by immersing into a benzene solution containing ZnOEP molecules, and the adlayer structures were characterized by scanning tunneling microscopy (STM). A hexagonally arranged ZnOEP array was formed on an Au(100)-(hex) surface, whereas a rectangularly arranged ZnOEP array was found on an Au(100)-(1 x 1) surface. The adlayer structure of ZnOEP was dependent upon the underlying Au atomic arrangements. Furthermore, an investigation of the spuramolecular assembly for these modified surfaces was carried out by using an open-cage C(60) derivative (opened C(60)). A supramolecular assembled adlayer with a 1:1 composition of opened C(60)/ZnOEP was formed on Au(100)-(hex), whereas aggregates of opened C(60) were found on the ZnOEP-modified Au(100)-(1 x 1) surface. Electrochemical responses of opened C(60) were significantly influenced by underlying ZnOEP arrays. This finding suggests that precise control of underlying ZnOEP adlayers with the Au atomic structure is important to recognize the opened C(60) on them.     

Asymmetric synthesis of the hydronaphthalene moieties of mevinic acids

The hydronaphthalene moieties of mevinic acids are synthesized enantioselectively by using the asymmetric intramolecular Diels-Alder reaction catalyzed by a chiral titanium reagent.     

Stereoselective reduction of β hydroxyketones to 1,3-diols highly selective 1,3-asymmetric induction via boron chelates

Highly selective asymmetric induction can be achieved in the reduction of acyclic β-hydroxyketones via boron chelates. Treatment of β-hydroxyketones (1) with tributyl or tri-isobutylborane and successively with sodium borohydride afforded syn-1,3-diols (3) in highly stereo-selective manner, Syn -α-substituted-β -hydroxyketones (8) were also reduced to give syn, syn-1,3-diols (9) exclusively. The reaction was further applied to the convenient preparation of 3-deoxy-hexoses.     

Structure of a 1:1 molecular complex of trans-9,10-dihydroxy-9,10-diphenyl-9,10-dihydroanthracene with ethanol

X-ray analysis of the title complex revealed hydrogen-bonded chains comprising two crystallographically independent types of $\text{trans}$-9,10-dihydroxy-9,10-diphenyl-9,10-dihydroanthracene molecules, in which the central 1,4-cyclohexadiene rings are respectively flat and very slightly puckered, with the ethanol molecules attached exclusively to the latter type.     

Anwendung des Alizarins und seiner Derivate zur Molybdänbestimmung

Zusammenfassung Eine Methode für die Bestimmung des Molybdäns mit Alizarinkomplexon wurde entwickelt und mit anderen Alizarin-Derivaten verglichen. In Alkohol-Wasser bildet sich bei pH 5 bei Alizarinkomplexon überschuß ein Komplex im Verhältnis 11, der bei 480 nm absorbiert. Der molare Extinktionskoeffizient ist 4,689 undK _f = 2,51 · 10⁵. Die Methode wurde zur Analyse einer Stahlprobe angewendet, wobei die störenden Elemente papierchromatographisch abgetrennt wurden.

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Use of alizarin and its derivatives for the determination of molybdenum

Summary A method has been developed for the determination of molybdenum with alizarin complexone and compared with other alizarin derivatives. In alcohol-water, and at pH = 5, and an excess of alizarin complexone, there is produced a complex, in the ratio of 11, which absorbs at 480 nm. The molar extinction coefficient is 4.689 and the K_f = 2,51 · 10⁵. The method was employed in the analysis of a specimen of a steel, whereby the interfering elements were separated off by paper Chromatographic means.

     

Separation of closely related structural isomers by inclusion complexation with tailor-made host compounds. Crystal structures of 2,2-di (p-hydroxyphenyl) propane and Its 1:1 complex withp-cresol

The crystal structures of the 2,2-di(p-hydroxyphenyl)propane host and its 1:1 adducts withm-andp-cresol guests have been studied. The preferential complexation of this host withp-cresol overm-cresol is related to the opposite trend exhibited by 1,1-di(p-hydroxyphenyl)cyclohexane; both hosts can separate effectively the two cresols from their liquid mixture by crystalline inclusion. A plausible explanation of the different inclusion features is provided by examining the intermolecular association in the corresponding solids. The analysed structures are stabilized by strong and continuous H-bonding between the constituent entities along two dimensions, and by weak van der Waals forces along the third axis. The p-cresol complex of the title host reveals a unique arrangement within and a more efficient packing of the layered structure, and thus represents a more stable and less soluble crystal lattice than itsm-cresol analog. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82099 (8 pages).     

Orientation control of perovskite thin films on glass substrates by the application of a seed layer prepared from oxide nanosheets

Orientation control of perovskite compounds was investigated by the application of a seed layer prepared from oxide nanosheets. An aqueous suspension of oxide nanosheets was prepared by the exfoliation of a layered compound of KCa₂Nb₃O₁₀ oxide grains. A seed layer composed of (TBA)Ca₂Nb₃O₁₀ nanosheets (TBA = tetrabutylammonium) was formed on a glass substrate by simply dip coating it in the suspension. Two kinds of perovskite compounds, LaNiO₃ (LNO) and Pb(Zr,Ti)O₃ (PZT) with a preferred orientation of (00l) were successfully grown on this seeded glass substrate. In this study, the relation between lattice mismatch and electrical properties is investigated. A large, oriented PZT film with a size of 5 ×4 cm shows an improved P-E hysteresis behavior by use of this orientation control.     

Magnetic structure of graphite ribbon

Anoble mechanism of spin polarization is proposed for finite graphite sheet with edge. For graphite ribbon with zigzag edge, there appear peculiar ‘edge states’. These localized states comprise nearly flat band at the Fermi level, which easily causes magnetic instability. Magnetic structure is suggested from Hartree-Fock analysis of the Hubbard model, where huge magnetic moments are induced at around both of edges by weak HubbardU and are coupled antiferromagnetically with each other.     

Preparation of multisubstituted allenes from allylsilanes

[reaction: see text] A three-step route of converting allylsilanes to functionalized allenes was developed. Thermal decomposition of 1,1-dibromo-2-(silylmethyl)cyclopropanes, which were quantitatively prepared by treatment of allylsilane derivatives with CHBr3/KO(t)Bu, afforded substituted 2-bromo-1,3-butadienes with elimination of bromosilanes. The Pd-catalyzed reaction of the bromodienes with soft nucleophiles gave the allene derivatives. Previously inaccessible tri- and tetrasubstituted allenes can be prepared by this method as well.     

Leaching behavior of metal-containing species in residual oils with different organic solvents

The leaching behavior of two different residual oils is investigated with 24 organic solvents including alkanes, aromatics, esters, ethers ketones, alcohols and nitrogen compounds. A 2-g portion of sample oil is shaken with 20 ml of the organic solvent. The leaching of the organic matrix of the oil is determined by weighing the dissolved organic matrix after removal of solvent. The leaching of vanadium, iron and nickel was determined by flame atomic absorption spectrophotometry after ashing of the dissolved fraction. The leaching of those metals depends strongly on the solvent used; for example, vanadine is almost completely leached into toluene, but only slightly into methanol. The leaching of iron is poor compared with that of vanadium or nickel. In most solvents, leaching of those metal-containing species is poorer than that of organic material. Exceptionally, N,N-dimethylformamide is more efficient in leaching vanadium species than organic material.