Formation of 3-Bromo-1,5- and −1,7-Azulenequinones from 1-Alkyl-and 1-Phenylazulenes by Substituent Extrusion on the Bromine- Oxidation in Aqueous THF. Remarkable Substituent Effects on the Product Distribution

Oxidation of 1-ethyl-, 1-propylazulenes, and their 5-isopropyl derivatives with bromine gave 3-bromo-1,5- and 3-bromo-l,7-azulenequinones (Type A) together with 3-bromo-l-hydroxy-5-isopropyl-l-alkylazulen-7-one and its isomeric products (Type B), while the same reaction of 1-methylazulenes afforded Type B products along with many unidentified products. On the other hand, 1-phenylazulene gave 3-phenyl-1,5- and 3-phenyl-l,7-azulenequinones (Type C) and Type B products in high yie]ds. 1,2-Polymethyleneazulenes afforded a considerable amount of 3-bromo-2-(ω-formylalkyl)azulenequinones together with Type B products. Possible pathways for the extrusion of the alkyl substituent at C-l are discussed.     

Sunlight induces N epsilon-(carboxymethyl)lysine formation from glycated polylysine-iron(III) complex

Sunlight was found to strongly induce the formation of N epsilon-(carboxymethyl)lysine (CML) from glycated polylysine in the presence of Fe(III) ion. The initial step of this Fe(III)-catalyzed CML formation was noted to be similar to that of blueprint photography as was confirmed by the production of Turnbull's blue in sunlight-exposed glycated human serum albumin ferricyanide solution in the presence of Fe(III). Based on this, photoinduced oxidative C-C bond cleavage of the Amadori compound was assumed to be initiated by photochemical single electron transfer front ligand to Fe(III) in the Fe(III)-Amadori compound complex affording the Fe(II)-Amadori compound radical intermediate, which eventually yields either CML or active oxygen species. CML is thus a useful oxidative stress marker. The mechanism proposed here would explain the high accumulation of CML in lens protein and skin actinic elastosis.     

On amide exchange reaction of polymide precursor

The reaction of poly(amic acid) (PAA) derived from pyromellitic dianhydride (PMDA) and oxydianiline (ODA) with 1-aminopyrene (APy) in solution as a model of amide exchange reaction between PAAs was studied in the temperature range of 0–60°C using viscometry and light-scattering (LS) measurements. The decrease in the weight-average molecular weight (M?_w) of PAA in N,N-dimethylacetamide (DMAc) solution with time and the acceleration of M?_w drop due to the increase in storage temperature or the addition of APy into PAA solution were observed. Apparent activation energies (E_a) for scission of PAA chains were similar: about 13 kcal/mol in PAA/DMAc and PAA/APy/DMAc, respectively. When stored at 60°C for a week, the number of scissions per polymer chain in PAA/DMAc is about 2, but is about 5 in PAA/DMAc with a large amount of APy. The result indicates that the M?_w drop accelerated by the addition of APy is attributed to amide exchange reaction between PAA Chains and monofunctional APy. It was concluded from the dependence of M?_w drop on Apy concentration that the exchange reaction between different PAA molecules during storage of PAA/PAA solution may scarcely occur under the conditions (storage time and temperature) used for preparation of PAA/PAA blends.     

Characterization of a Co-CoO obliquely evaporated magnetic tape by analytical electron microscopy and electron holography.

The microstructure and magnetic domain structure of a Co-CoO obliquely evaporated tape for magnetic recording are studied by analytical electron microscopy and electron holography, respectively. While the existence of Co and CoO crystallites is confirmed by energy-filtered electron diffraction, columnar structure of the Co crystallites surrounded by the densely packed CoO crystallites is visualized by an elemental mapping method with electron energy loss spectroscopy, and the crystal orientation relation among the Co crystallites is clarified by high-resolution electron microscopy. It is found that the neighboring Co crystallites have close crystal orientations. On the other hand, electron holography reveals the magnetic flux distribution in a thin section of the tape. Although there exists the background resulting from the effect of inner potential with thickness variation, the distribution of lines of magnetic flux is found to correspond well to the recorded pattern.     

Dielectric properties of stereoregular poly(methyl methacrylates)

To obtain more useful information about the effect of the degree of stereoregularity on the motion of the polymer chain, the dielectric and dilatometric measurements were made for a series of stereoregular poly(methyl methacrylates) (PMMA). The α- and β-absorptions were observed in each sample, of which the dielectric behaviors of the α-process are discussed. The temperature dependence of the relaxation time of the α-process was sufficiently represented by the WLF equation and the resulting values of the parameters f_g and B in the modified WLF equation were found smaller for isotactic-rich PMMA than those values for syndiotactic PMMA. It may be deduced from these results that the chain mobility of the isotactic PMMA is larger than that of the syndiotactic. The dielectric increment of the α-process in the isotactic PMMA is much larger than that in the syndiotactic PMMA, increasing rapidly with temperature, and taking its maximum in the temperature range of 55 to 60°C. The dielectric transition was clearly observed in the case of isotactic-rich PMMA.     

Preparation and analysis of reactively evaporated a-Si:H

a-Si:H formed by the method of reactive evaporation of silicon with supplying hydrogen ion has much the same properties as films prepared by silane grow discharge (GD) decomposition. Growth kinetics in this method is described. Hydrogen ion suppresses the oxidation of silicon and it is incorporated as mono-hydride, whose content is proportional to hydrogen ion current. Adsorption energy of hydrogen ion is some 130 meV. Dark conductivity of a-Si:H depends mainly on energy gap associated with hydrogen content. Spin density is determined by the collision phenomenon between Si-H and spin in depositing.     

Photo-induced alignment of a photo-crosslinkable liquid-crystalline copolymer film by linearly polarized UV light

The anisotropic photoreaction of a liquid-crystalline (LC( copolymer comprising one co-monomer being anisotropically photo-crosslinkable by linearly polarized (LP( -UV light and the other being insensitive to UV-irradiation is presented. Polarized UV and IR studies suggested a photo-induced alignment of the mesogenic side groups during the LP-UV photoreaction at the LC temperature range of the copolymer. The direction of the aligned mesogenic groups is parallel to the electric vector of the incident LP-UV light and the induced birefringence is 0.07.     

The Adsorption of CHClF2 on NaY5.6 Zeolite

The adsorption of CHClF₂ on NaY5.6 zeolite has been studied by measuring the H and F NMR of the adsorbed CHClF₂, focusing in particular on the measurements of the chemical shift and longitudinal relaxation time, as well as the adsorption isotherm measurements. It is possible to determine the coordination structure of the CHClF₂ adsorbed on NaY5.6 zeolite by measuring the adsorption amount dependence of the chemical shift. In addition, the motional activity of the adsorbed molecules in the super cage of the zeolite is discussed on the basis of observed longitudinal relaxation times for various adsorption amounts.     

A novel tandem [2 + 2] cycloaddition-Dieckmann condensation with ynolate anions. Efficient synthesis of substituted cycloalkenones and naphthalenes via formal [n + 1] cycloaddition.

A novel tandem [2 + 2] cycloaddition-Dieckmann condensation via ynolate anions is described. Ynolate anions are useful for the formation of reactive beta-lactone enolates via a pathway not involving the enolization of the corresponding beta-lactones. The [2 + 2] cycloaddition of ynolate anions with delta- or gamma-keto esters, followed by Dieckmann condensation, gives bicyclic beta-lactones, which are easily decarboxylated to produce synthetically useful 2,3-disubstituted cyclopentenones and cyclohexenones in one pot. This tandem reaction was applied to a novel, one-pot synthesis of highly substituted naphthalenes.     

Validation of real-time PCR analyses for line-specific quantitation of genetically modified maize and soybean using new reference molecules

Novel analytical methods based on real-time quantitative polymerase chain reactions by use of new reference molecules were validated in interlaboratory studies for the quantitation of genetically modified (GM) maize and soy. More than 13 laboratories from Japan, Korea, and the United States participated in the studies. The interlaboratory studies included 2 separate stages: (1) measurement tests of coefficient values, the ratio of recombinant DNA (r-DNA) sequence, and endogenous DNA sequence in the seeds of GM maize and GM soy; and (2) blind tests with 6 pairs of maize and soy samples, including different levels of GM maize or GM soy. Test results showed that the methods are applicable to the specific quantitation of the 5 lines of GM maize and one line of GM soy. After statistical treatment to remove outliers, the repeatability and reproducibility of these methods at a level of 5.0% were <13.7 and 15.9%, respectively. The quantitation limits of the methods were 0.50% for Bt11, T25, and MON810, and 0.10% for GA21, Event176, and Roundup Ready soy. The results of blind tests showed that the numerical information obtained from these methods will contribute to practical analyses for labeling systems of GM crops.