Halogen catalyzed acetylenic oxy-cope rearrangement in N-methyl-2-pyrrolidone solvent a new industrial process for pseudoionone and its analogues

Selective synthesis of pseudoionone was achieved by the acetylenic oxy-Cope rearrangement of 4-isopropenyl-3,7-dimethyl-6-octen-1-yn-3-ol ($\text{3}$) in N-methyl-2-pyrrolidone solvent containing a trace of hydrochloric acid, hydrobromic acid, iodine, ammonium bromide and ammonium chloride catalysts.     

Multichannel autosampler for Curie-point pyrolysis capillary gas chromatography

A multichannel autosampler which can automatically analyze up to 20 samples in sequence has been developed for on-line Curie-point pyrolysis – capillary GC. The results obtained from the system show that the analysis of thermally labile samples could be performed without either thermal degradation or reaction during the waiting time before the final pyrolysis. The reproducibilities of the relative peak areas and retention times of the characteristic pyrolysates of a tricomponent copolymer were significantly better than those obtained by manual sample manipulation.     

Intermolecular hydrogen bonding of steroid compounds: PFG NMR diffusion study, cold-spray ionization (CSI)-MS and X-ray analysis

An extensive analysis of hydrogen bonding of steroid compounds in diluted solution is preformed by pulsed field gradient (PFG) NMR and cold-spray ionization (CSI)-MS, in the solid state by X-ray crystallographic analysis. The formation of hydrogen bond interaction are quantified and discussed. Although X-ray analysis in the crystalline state and CSI-MS measurement in solution suggested that the observed diffusion coefficient D(obs) of the steroid compounds may vary in accordance with the number of hydrogen bonds, the actual observed D(obs) value determined from the diffusion studies diminished constantly without correlation on the decreasing numbers of hydrogen bonds. Comparison of two different calibration profiles of calculated molecular volume (V(cal)) vs. D(obs), which are obtained from compounds possessing no hydrogen bonding and the steroid compounds, formation of a chain structure (cluster) based on intermolecular hydrogen bonding of the steroid compounds is unambiguously confirmed.     

Preparation and properties of highly conductive La1−x M x MnO3−y thin film showing magnetic effect from sol-gel process

The sol-gel synthesis of Sr-doped-LaMnO₃ thin film was investigated. The optimum condition was obtained when strontium, lanthanum and manganese nitrates were used as raw materials and diethylene or propylene glycol was used as solvent. An alumina plate was used as a substrate. The film thickness was about 0.2 m for one dip coating. The conductivity of Sr-substituted-LaMnO₃ increased with increasing Sr content and showed ferromagnetic properties. The conduction mechanism was a hopping conduction due to the small polaron. The metal-semiconductor transition at around room temperature was considered to be caused by the Jahn-Teller effect.     

Synthesis and characterization of new cyclopalladated carbene complexes

Di-μ-chlorobis(2-methyl-2-methoxy-3-t-butylthiopropyl)dipalladium(II) reacted with bis(1,3-diphenyl-2-imidazolidinylidene) to afford a new chlorobridged carbene complex [{PdCl(did)}₂] (did  1,3-diphenyl-2-imidazolidinyl-idenato,2-C,2′-C) in 46.2% yield, which has a cyclopalladated chelate structure involving a Pd—carbene and a Pd—aryl bond; new carbene complexes, [{PdBr(did)}₂], [{Pd(CH₃COO)(did)}₂], [Pd(acac)(did)], and [PdCl(did)Q] (Q  4-MePy, P[OCHMe₂]₃) were also prepared from [{PdCl(did)}₂].     

Photometric determination of traces of antimony with rhodamine b after sulfide precipitation

A method is described for the colorimetric determination of as little as a few tenths of a part per million of antimony in samples composed primarily of elements of atomic numbers 1–28 (e.g., geo materials).Antimony is isolated by sulfide precipitation in mineral acid medium after reduction of ferric iron with hydroxylamine hydrochloride, with final determination by rhodamine B-benzene extraction. The procedure provides for the presence of gallium, thallium, tungsten and gold.     

Magnetization of ferromagnetic clusters

The magnetization and deflection profiles of magnetic clusters in a Stern-Gerlach magnet are calculated for conditions under which the magnetic moment is fixed in the intrinsic frame of the cluster, and the clusters enter the magnetic field adiabatically. The predicted magnetization is monotonic as a function of the ratio of magnetic energy ₀ B to the rotational thermal energyk _BT. In low field the average magnetization is 2/3 of the Langevin function. The high-field moment approaches saturation asymptotically asB ^–1/2 instead of theB ^–1 dependence in the Langevin function     

Extraction of tetrafluoroborate with crown ethers and its application to silicate rock analysis

Summary The extraction behaviour of tetrafluoroborate with crown ethers was studied. A high distribution ratio of tetrafluoroborate is obtained by extraction with dicyclohexano-18-crown-6 (DC18C6) in an organic solvent of high dielectric constant from potassium fluoride solution. The molar ratios of crown ether to KBF₄ in the extracted species are probably 1:1 for DC18C6, dibenzo-18-crown-6 and 18-crown-6, and 2:1 for benzo-15-crown-5 and 15-crown-5. The flow-injection extraction-spectrophotometric determination of tetrafluoroborate with Brilliant Green was worked out. Many rock reference samples were analyzed for boron (1–150 ppm).     

TG-MS analysis of the thermal decomposition of pig bone for forensic applications

In order to investigate the potential of thermal analysis for the determination of post-mortem age, rib bone specimens were collected from the remains of a number of slaughtered pigs that were allowed to decompose in the Australian bush in a controlled site under a range of conditions for time periods ranging from 1 to 5 years. The bone specimens were cut in cross-section with the compact bone collected for analysis. TG-MS curves were collected by heating bone samples to 1100°C in an argon atmosphere. The TG-MS data showed significant differences for the pig bone specimens derived from the different environments and showed trends in peak size correlating with age. The reported data suggest that TG-MS has significant potential for the identification of origin as well as the ageing of skeletal remains in a forensic context.     

Intramolecular nonbonded S...N interaction in rabeprazole

Intramolecular nonbonded S...N interactions in the crystal structures of the derivatives (7a-d) of sodium rabeprazole (1) and an intermolecular nonbonded S...N interaction between ethylmethylsulfoxide and pyridine in a solution were recognized. These results made us estimate that the intramolecular nonbonded S...N interaction existed in 1 and its derivatives in a solution, and formed the 4-membered quasi-ring in 2 (Fig. 1) followed by the increase of the reactivity of 2 to give the putative spiro sulfoxide 3, which is the key intermediate in the reaction cascade of 1 (Chart 1).