Reactions of zirconacyclopentadienes with C [double bond] ), C [double bond] N, and N [double bond] N moieties with electron-withdrawing groups: formation of six-membered heterocycles

Reactions of zirconacyclopentadienes with diethyl ketomalonate gave alpha-pyrans in excellent yields in the presence of BiCl3. In the absence of BiCl3, zirconacyclopentadienes did not react with diethyl ketomalonate. Tetraphenylzirconacyclopentadiene reacted with diethyl ketomalonate in the presence of BiCl3 to give a ring-opening product, dienolic ether, in 53% yield. The structures of the alpha-pyran prepared from diethyldiphenylzirconacyclopentadiene and the ring-opening product were determined by X-ray analysis. When oximinosulfonate was added to tetraethylzirconacyclopentadiene in THF at -78 degrees C, 3,4,5,6-tetraethylpyridine-2-carbonitrile was obtained in 95% yield within 10 min. The structure of the product was confirmed by X-ray analysis. When tetraethylzirconacyclopentadiene was treated with azodicarboxylate in the presence of 2 equiv of CuCl at -78 degrees C, 1,2-dialkoxycarbonyl-3,4,5,6-tetraethyl-1,2-dihydropyridazine derivatives were obtained. The structure of one of dihydropyridazine was also confirmed by X-ray analysis.     

Conformational analysis of the NMDA receptor antagonist (1S,2R)-1-phenyl-2-[(S)-1-aminopropyl]-N,N-diethylcyclopropanecarboxamide (PPDC) designed by a novel conformational restriction method based on the structural feature of cyclopropane ring

(1S,2R)-1-phenyl-2-[(S)-1-aminopropyl]-N,N-diethylcyclopropanecarboxamide (2b, PPDC), a new class of potent N-methyl-D-aspartic acid (NMDA) receptor antagonist, was designed based on a new method for restricting the conformation of compounds having a cyclopropane ring. The three-dimensional structures of PPDC obtained by the three different methods of X-ray crystallographic analysis, usual MM2-calculations in vacuum, and MM2 calculations based on the nuclear Overhauser effect (NOE) data in D2O are similar, which are in accord with that hypothesized. These results suggest that this conformational restriction method is particularly effective in designing novel biologically active molecules.     

Spatial and seasonal behaviour of organotin compounds in protected subtropical estuarine ecosystems in Okinawa,Japan

The spatial and temporal behaviours of the organotin compounds (OTCs) (butyl- and phenyltin) were investigated in the Manko and Okukubi protected estuarine ecosystems on Okinawa Island, Japan from February to October 2006. Butyltin compounds (BTCs) were frequently detected in all seasons, while phenyltin (PhTs) were found in winter and early spring. In Manko estuary, the total mean concentrations of BTCs and PhTs were 22.78?±?30.85, (mean?±?SD, n?=?53) and 0.08?±?0.27?ng(Sn)?L^?1, respectively. In Okukubi estuary, BTCs and PhTs were 12.58?±?23.96 and 0.47?±?1.67 (n?=?55) ng(Sn)?L^?1, respectively. The Manko sediments can be classified as lightly contaminated, while the Okukubi sediments were uncontaminated with tributyltin (TBT). The mean levels of TBT shown in Manko estuary exceeded the threshold level and represent an ecotoxicological risk to sensitive aquatic life. Generally, the present study reports the occurrence and continuous input of OTCs in the protected estuaries, even 16 years after legal restriction of TBT usage in coastal waters was implemented by the Japanese Environmental Authorities.     

Another approach to characterizations of generalized triangle inequalities in normed spaces

In this paper, we consider a generalized triangle inequality of the following type: $$\left\| {x_1 + \cdots + x_n } \right\|^p \leqslant \frac{{\left\| {x_1 } \right\|^p }} {{\mu _1 }} + \cdots + \frac{{\left\| {x_2 } \right\|^p }} {{\mu _n }}\left( {for all x_1 , \ldots ,x_n \in X} \right),$$ where (X, ‖·‖) is a normed space, (µ₁, ..., µ _n ) ∈ ? ⁿ and p > 0. By using ψ-direct sums of Banach spaces, we present another approach to characterizations of the above inequality which is given by [Dadipour F., Moslehian M.S., Rassias J.M., Takahasi S.-E., Nonlinear Anal., 2012, 75(2), 735–741].     

Reduction of core loss in non-oriented (NO) electrical steel by electroless-plated magnetic coating

An important issue in development of electrical steels for core-laminated products is to reduce core loss to improve energy conversion efficiency. This is usually obtained by tailoring the composition, microstructure, and texture of electrical steels themselves. A new technique to reduce core loss in electrical steel has been investigated. This technique involves electroless plating of magnetic thin coating onto the surface of electrical steel. The material system was electroless Ni–Co–P coatings with different thicknesses (1, 5, and 10 μm) deposited onto the surface of commercially available Fe–3% Si electrical steel. Characterization of deposited Ni–Co–P coating was carried out using X-ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive X-ray (EDX) spectrometer. The deposited Ni–Co–P coatings were amorphous and composed of 56–59% Ni, 32–35% Co, and 8–10% P by mass. The effect of coatings on core loss of the electrical steel was determined using single sheet test. A core loss reduction of 4% maximum was achieved with the Ni–Co–P coating of 1 μm thickness at 400 Hz and 0.3 T.     

Dynamics of formation of CN(B2Σ+) fragment from HCN and DCN in an argon afterglow

The dissociative excitation of HCN and DCN producing CN(B²Σ⁺) in collision with Ar(³P_0,2) was investigated in a flowing afterglow. The Δν = 0, ?1, and ?2 sequences of the CN(BX) violet emission were analyzed by computer simulation, and the vibrational and rotational distributions of the CN(B²Σ⁺) fragment were obtained. Possible reaction pathways were studied on the basis of a linear surprisal analysis of the observed distributions and their isotope effects.     

Sulfur-containing polymers. V. Preparation of polyoxycarbonylsulfenamides by polycondensation of bis(oxycarbonylsulfenyl chlorides) with diamines

Polyoxycarbonylsulfenamides (POSA) have been prepared by interfacial polycondensation of bis(oxycarbonylsulfenyl chlorides) with diamines. The polymers obtained ranged in physical form from crystalline solids to resinous materials depending on the kind of both bis(oxycarbonylsulfenyl chlorides) and diamines used. Some of the polymers gave transparent pliable films from chloroform solution. The polymer films decomposed with liberation of carbonyl sulfide on being subjected to ultraviolet radiation.     

A novel immobilized-enzyme system utilizing microcapsules

A novel immobilized-enzyme system that has glucoamylase on the surface of, and glucose oxidase within, polyurea microcapsules was developed. This system was found to carry out its sequential enzymatic reaction effectively. It was also demonstrated that the use of microcapsules was useful for this immobilized-enzyme system since a large amount of the second enzyme, glucose oxidase, was required for the sequential reaction to proceed efficiently. In addition, this system was found helpful for making the size of reaction batches smaller.     

Penning ionization electron spectroscopy and photo-electron spectroscopy of molecular solids. II. Ammonia and water

The Penning ionization electron spectra (PIES) and ultraviolet photoelectron spectra (UPS) of ammonia and water molecules condensed on a cold metal substrate have been measured using thermal He*(2³S, 2¹S) metastable atoms and He(I) (58.4 nm) photons. The shifts of the observed positions of the PIES peaks relative to those of the UPS peaks in the condensed phase are roughly equal to the corresponding shifts in the gas phase. The relative intensities of the 3a₁ and 1e orbital peaks are reversed in the PIES and UPS for both gaseous and condensed ammonia; the origin of this reversal is interpreted as the difference between the interactions with metastable atoms and photons. On the other hand, the relative intensities of the 3a₁ orbital peak in the PIES and UPS for condensed water decrease as compared to the gas-phase spectra. This implies participation of the 3a₁ orbital of water in the hydrogen bonding.