X-ray structure and NMR assignment of 3,4-dimethylthioquinoline

The title compound (C₁₁H₁₁NS₂) is monoclinic:P2₁/c,a=15.200(4),b=14.644(4),c=10.098(3),Z=8. The structure was solved by direct methods, and refined to anR value of 0.047 with 2886 independent reflections. There are two nonequivalent molecules in the unit cell. BothS-methyl groups have different spatial orientation: the-methyl group side-chain is approximately coplanar with the pyridine ring and turned to the ortho-position, but -methyl group side-chain is turned over this ring. Both¹H and¹³C NMR spectra were assigned using 1D and 2D experiments. The NOE measurements are consistent with inter-proton distances from X-ray data.Part XV in the series of Azinyl sulfides.     

X-ray structure of 4-chloro-3′-methylthio-3,4′-diquinolinyl sulfide

The title compound crystallizes in a monoclinic space groupP2₁/n witha=9.524(3),b=6.782(2),c=26.217(6) Å, =92.52(4)°. The values of the Cl...S and S...S distances are well below the sum of the van der Waals radii of the heteroatoms. Also, the Cl–C–C(S) and (Cl)C–C–S bond angles are below the standard 120°. This indicates a attractive interaction between both pairs ofortho-situated heteroatoms.Part XXXVIII in the Series of Azinyl Sulfides.     

Synthesis of New Primary-Tertiary Alkyl Bisperoxides by Reaction of Tertiary Hydroperoxides with Bromoalkanesin a PTC System

Summary.  Syntheses of novel primary-tertiary bisperoxides were carried out under phase transfer catalysis conditions. The bisperoxides were obtained in good yields, the reaction times not exceeding four hours. Received January 15, 2001. Accepted (revised) February 9, 2001     

The influence of NH3 on NO2 conversion in a dc corona discharge in N2:O2:CO2:NO2:NH3 mixture

The aim of this paper is to investigate the influence of NH₃ additive (540–1470 ppm) on the conversion of NO₂ and the creation of NO and N₂O in a mixture of N₂:O₂:CO₂: NO₂:NH₃ subjected to the so-called direct current (dc) corona discharge. The dc corona discharge was generated in a needle-to-plate reactor. Seven positively polarized needles were used as one electrode and a stainless steel plate as the other. The time-averaged discharge current was varied from 0 to 7 mA. It was found that the dc corona discharge decomposed NO₂ and produced NO and N₂O. The reduction of NO₂ was higher without NH₃ additive if the residence time of the operating gas was relatively short. However, in a longer corona discharge processing the NH₃ additive may be useful for reduction of NO₂.Supports from the Research and Development Commitee (KBN) under Programme KBN 0889/P4/93/04 and the Polish Academy of Sciences within IMP 3.1 project are gratefully acknowledged.     

High-resolution emission spectroscopy of the AΠ–XΣ system of AlH

The emission spectrum of the A²Π–X²Σ⁺ system of the AlH⁺ ion was investigated in the range of 27 000–29 000 cm⁻¹ by using a conventional spectroscopic technique. The AlH⁺ molecules were formed and excited in an aluminium hollow-cathode lamp with two anodes, filled with a mixture of Ne carried gas and a trace of NH₃. The emission from the discharge was observed with a plane grating spectrograph and recorded by a photomultiplier tube. The full rotational structure of the 0-0 and 1-1 bands has been observed for the first time (12 branches up to J″ = 36.5) and many new constants of the X²Σ⁺ state have been derived from the analysis. For the A²Π, v = 0 and 1 state a considerable irregularities of the Λ-doubling have been observed. The most reasonable explanation for this anomaly is an interaction with unstableness rotational levels of X²Σ⁺ state and perturbing of the A²Π state by the nearly lyingB²Σ⁺ state.     

Ceramic electrolytes based on (Ba1 − x Ca x )(Zr0.9Y0.1)O3 solid solution

The aim of this work was to study the electrical and electrochemical properties of the (Ba_1???x Ca _x )(Zr_0.9Y_0.1)O₃ solid solutions. The powders of different calcium content (x?=?0, 0.05, 0.1, and 1) were prepared by a thermal decomposition of organo-metallic precursors containing ethylenediaminetetraacetate acid. X-ray diffraction analysis showed that a small substitution of calcium for barium caused formation of cubic solid solutions with the decreasing cell parameters. Electrical conductivity measurements were performed by the d.c. four-probe method in controlled gas atmospheres containing Ar, air, H₂, and/or H₂O at temperature from 300 to 800 °C. It was found that the conductivity depended on a chemical composition of the samples and the atmosphere. Overall, the electrical conductivity was higher in wet atmospheres that contained oxygen that was in accordance with the model of a proton transport in perovskite structure which assumed the presence of the oxygen vacancies. The solid solution containing 5 mol% of calcium showed the highest conductivity and the lowest activation energy of conductivity regardless of the atmospheres; this can be attributed to the local changes in the cubic perovskite structure. Test results for CaZr_0.9Y_0.1O₃ used as an electrolyte in solid oxide galvanic cells involving CaCr₂O₄ as a reference electrode are also reported.     

Search for bioactive compounds from Cantharellus cibarius

Ground fruit bodies of Cantharellus cibarius (chanterelle) were extracted with dichloromethane and subjected to CC followed by preparative HPLC, which led to the isolation of glycerol 1,2- and 1,3-dilinoleates and glycerol tridehydrocrepenynate. Extraction of C. cibarius fruit bodies with ethanol or methanol afforded fatty acid ethyl or methyl esters as a result of esterification/transesterification reactions. Insecticidal activity of the isolated glycerides and esters was much lower than that of the crude extracts and chromatographic fractions suggesting a synergistic effect of some of the compounds present in the mixture.