Structural study of self-assembled monolayers of ferrocenylalkanethiols on gold by angleresolved X-ray photoelectron spectroscopy

An angle-resolved X-ray photoelectron spectroscopic study has been performed on structures of self-assembling systems, viz ferrocenylthiols on a gold (111) crystal. The angular dependence of the intensities of photoemission reveals that ferrocenyl groups are on the outermost layer, separated from the gold substrate by hydrocarbon chains of the thiol groups.     

PTX phase equilibrium study of new solid solution systems,Cd1−xMxS (M = Mg,Ca, Sr)

Pressure, temperature, and composition phase equilibrium diagrams of new solid solution systems of the Cd_1?xM_xS (M = Mg, Ca, Sr) type were investigated using the quenching method. The stable region for the rock-salt-type phase is widely extended toward the high-temperature/low-pressure region by substituting 10–20 mole% of Cd with Ca or Sr. Temperature and composition phase diagrams for each solid solution system were obtained at 2 GPa. The rock-salt-type phase stability is discussed in view of these phase relations.     

Differential pulse polarographic determination of l-lactate with a soluble enzyme preparation

Summary An electrochemical method for the determination of l-lactic acid using the specific reaction of lactate oxidase, has been studied and applied to lactic acid beverage and yoghurt. The technique is reasonably rapid and simple to perform. The calibration curve is linear in the concentration range from 1.0 to 20 mol/l, the reproducibility (R.S.D.) at 10 mol/l l-lactic acid is 1.34% (n=6) and the detection limit is 0.29 mol/l (k=2). The method can possibly be used for monitoring l-lactate or l-lactic acid in food industries and clinical laboratories.     

Interpretation of electronic spectra by configuration analysis: Absorption spectra of monosubstituted naphthalenes

The electronic absorption spectra of four monosubstituted naphthalenes, α-, β-naphthols, and α-, β-naphthylamines have been investigated by means of configuration analysis with particular attention to the dependence of spectra on the position of substitution and on the electron-donating power of the substituent. The results of molecular orbital calculations based on the Pariser-Parr-Pople method are analyzed in terms of locally excited states and intramolecular charge-transfer configurations. The characteristic changes in location and polarization of the L_b, L_a, and B_b bands caused by substitution at the α- or β-position are adequately explained by the analysis. Two strong absorption bands of α-substituted naphthalenes, which appear in place of the B_b band of naphthalene, are shown to result from a mixing of the $\text{B}{}_{\mathrm{3u}}{}^{\mathrm{+}}\text{(B}{}_{\mathrm{b}}\text{)}$ and $\text{A}{}_{\mathrm{g}}{}^{\mathrm{?}}$ states. The amino group exerts a great influence on the electronic structure of the parent molecule, so that the B_b band cannot be identified in the spectrum of β-naphthylamine.     

On weyl's gauge field in a non-local field

In this paper, a non-local field (i.e. the (x, ψ)-field) is constructed by regarding the spinor (ψ) as the internal freedom attached to each point (x). Since this field is likened to a unified field between the (x)- and (ψ)-fields, the metric is given bydσψ=gλ dx ^λψ. Concerning this, some conformally equivalent relations are considered. Next, Weyl's gauge field is introduced into the concept of connection in order to consider the gauge invariance. Finally, some essential features underlying our non-local field are grasped by formulating some fundamental equations of the spin curvature tensors.     

Combinatorial problems on series-parallel graphs

This paper outlines the results and motivation of the paper [1], in which we showed, in a unified manner, that there exist linear time algorithms for many combinatorial problems defined on the class of series-parallel graphs.     

Sonochemical preparation of composite nanoparticles of Au/gamma-Fe2O3 and magnetic separation of glutathione

We prepared Au/gamma-Fe2O3 composite nanoparticles by sonochemically reducing Au(III) ions employing no stabilizer in the aqueous solution to form stable Au nanoparticles and allowing them to attach onto the surface of gamma-Fe2O3 particles with an average size of 21 nm. Size of the formed Au nanoparticle depended on the initial concentration of Au(III) ions. The number of the Au nanoparticles, supported on each gamma-Fe2O3 particle was controlled by changing the relative amounts of Au(III) ions and gamma-Fe2O3 particles. The composite nanoparticles exhibited a high affinity with glutathione, a tripeptide with mercapto group so that separation and manipulation of glutathione in aqueous solutions could be performed by application of external magnetic field. Because the surfaces of the Au nanoparticles were not shielded by any stabilizers, or naked, sonochemically prepared Au/gamma-Fe2O3 composite nanoparticles seemed to show stronger affinity to the glutathione than those by the radiochemical method.     

Substituent effect of the coordinated pyridine in a series of pyrazolato bridged dinuclear diiron(II) complexes on the spin-crossover behavior

Two series of pyrazolato bridged dinuclear NCS and NCBH3 diiron(II) complexes with various types of 3- or 4-substituted pyridines, [{Fe(NCS or NCBH3)(X-py)}2(mu-bpypz)2], were prepared and their variable-temperature magnetic susceptibilities were measured. There were found linear correlations of the spin-crossover temperatures Tc not only between the NCS and NCBH3 complexes with the corresponding substituted pyridines, but also between the Tc and the Hammett constants, supporting the electronic substituent effect of the coordinated pyridine rather than a steric effect. The ligand field and the interelectronic repulsion parameters together with the thermodynamic data and/or cooperativity factor were discussed in relation with their spin-crossover behavior.     

X-ray absorption spectroscopic study on the electronic structure of Li(1)(-)(x)()CoPO(4) electrodes as 4.8 V positive electrodes for rechargeable lithium ion batteries

Changes in the electronic structure of olivine Li(1-x)CoPO(4), 4.8 V positive electrode material for lithium ion batteries, were investigated using the X-ray absorption spectroscopy (XAS) technique. The threshold energy in the Co K-edge increased with electrochemical Li removal, indicating the oxidation of cobalt ions due to charge compensation. Moreover, P and O K-edge XAS showed a slight shift in threshold energy with Li removal. Although it is generally believed that the electrons of PO(4) polyanion do not contribute to the oxidation process, present experimental results indicate changes in the electronic structure around PO(4) units. Such results would be interpreted by the idea of the hybridization effect between the Co 3d and O 2p orbitals and of the polarization effect introduced by Li ions.     

Yaequinolones J1 and J2, novel insecticidal antibiotics from Penicillium sp. FKI-2140

[chemical reaction: see text]. Two novel insecticidal antibiotics with a p-methoxyphenylquinolinone skeleton fused with a pyran ring, yaequinolones J1 (1) and J2 (2), have been isolated from Penicillium sp. FKI-2140, and structures were elucidated by spectroscopic studies including various NMR experiments. The relative stereochemistries were assigned by NOE experiments. Yaequinolones J1 and J2 showed toxicity against Artemia salina (brine shrimp) with the MIC value of 6.25 microg/mL.