摘要:

AbstractIn the reaction of oximes I with ethoxyethyne II at 75‐90° orthoesterlike products III are formed. Some aldoximes, however, are dehydrated to nitriles. The results are summarized in Table

ISSN:0165-0513    

DOI:10.1002/recl.19600790902

出版商:WILEY‐VCH Verlag    

年代:1960

数据来源: WILEY

摘要:

AbstractThe possibility of applying gamma ray analysis to approximately 50 mg samples of monazite has been investigated. Three ranges of low energy gamma radiation, under 0.3 MeV, were counted with a Gamma Scintillation Spectrometer.This extremely simple method led to very good results with samples containing only one radioactive component. With monazites containing uranium as well as thorium, the latter component being in excess, results were also good. For uranium contents that were only a few tenths of a per cent, the results did not attain the precision of chemical analysis.In a leached mineral where the simultaneous contents of uranium, radium in excess and thorium had to be determined, the method failed, due to the smallness of the contribution of UX in the emitted radiation with respect to that of the radium family. In this case we were able to calculate an approximate value for the thorium content and make a rough estimate of the total radium content of the mineral.With this spectrometer the use of longer counting times gives only a slight improvement in the precision of the counts. The use of somewhat larger samples will however diminish the important background fraction in the low activity countings and hence it will give a corresponding increase in the reliability of the results.

ISSN:0165-0513    

DOI:10.1002/recl.19600790903

出版商:WILEY‐VCH Verlag    

年代:1960

数据来源: WILEY

摘要:

AbstractThe reaction between TiCl4and AlEt3, AlEt2Cl and AlEtCl2at 80°C in isooctane was investigated for those Al/Ti ratios at which brown precipitates are formed. In these reactions Ti(IV) is not reduced beyond Ti(III). The extent of reduction was determined by oxidimetry and colorimetry; the two methods gave concordant results.Among the gaseous reaction products ethyl chloride was determined quantitatively by gas chromatography. Its formation is ascribed to a secondary reaction:\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm TiCl}_4 + {\rm C}_2 {\rm H}_5 \to {\rm TiCl}_3 + {\rm C}_2 {\rm H}_5 {\rm Cl}.$$\end{document}The C2H5radicals are formed in the main reaction in which the ethyl‐aluminium chlorides are converted into AlCl3and the triethylaluminium into Al2EtCl5.By means of the conversions indicated above the relation between the percentage of reduction of Ti(IV) to Ti(III) and the Al/Ti ratio is accounted for quantitatively. The precipitates formed in the system AlEt3/TiCl4were found to consist mainly of the brown modification of TiCl3in which about one sixth of the titanium is replaced by alumini

ISSN:0165-0513    

DOI:10.1002/recl.19600790904

出版商:WILEY‐VCH Verlag    

年代:1960

数据来源: WILEY

摘要:

AbstractData are presented in support of the view that the photochemical conversion of ergosterol into precalciferol, involving a cleavage of the cyclohexadiene‐ring, belongs to a generally occurring type of photochemical isomerisations. Under the influence of ultraviolet light 1,3‐cyclohexadiene itself is converted to trans‐1,3,5‐hexatriene. Irradiation of α‐phellandrene (1‐methyl‐4‐isopropyl‐1,5‐cyclohexadiene), results in a mixture of compounds, mainly consisting of (geometrical isomers of) 3,7‐dimethyl‐1,3,5‐octatriene. By ultraviolet‐ and infrared spectroscopy, hydrogenation, gas liquid partition chromatography and ozonolysis the identity of these irradiation products could be established. Indications were found that optically active α‐phellandrene might partly racemise during irradiation.Prolonged irradiation of cyclohexadiene and α‐phellandrene resulted in a large decrease of the extinction in the region 220‐300 mμ. On irradiation of the compounds at liquid air temperature in solid solution such a decrease was not observed. From this it was tentatively concluded that in the course of the photochemical reaction at room temperature a relatively s

ISSN:0165-0513    

DOI:10.1002/recl.19600790905

出版商:WILEY‐VCH Verlag    

年代:1960

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19600790906

出版商:WILEY‐VCH Verlag    

年代:1960

数据来源: WILEY

摘要:

AbstractThe addition of electrophilic reagents to ethyl (ethylthio)propynoate II occurs at carbon atom 2. Uncharged nucleophilic reagents (amines) are also added at carbon atom 2, but charged nucleophiles (ethoxide ion and the carbanion of malonic ester) interact at carbon atom 3. Additions to the anilide of (ethylthio)propynoic acid (XVIII) take a similar course. The results are discussed and explained.

ISSN:0165-0513    

DOI:10.1002/recl.19600790907

出版商:WILEY‐VCH Verlag    

年代:1960

数据来源: WILEY

摘要:

AbstractMeasurements of the electro‐osmotic transport of liquid in the germanium (powder) electrolyte solution were carried out. The results can be explained by a theory, which is given byVerwey and Payens, which was originally proposed for surface layers consisting of weakly ionized fatty acids. In the case of germanium it should be assumed that a weakly ionized germanic acid is present at the surface, giving the surface a negative charge. The experiments almost break down whenp‐type Ge is used. This can be explained by potential current characteristics usingp‐type orn‐type Ge as th

ISSN:0165-0513    

DOI:10.1002/recl.19600790908

出版商:WILEY‐VCH Verlag    

年代:1960

数据来源: WILEY

摘要:

AbstractA survey is given of the characteristic frequencies of a number of alkylthio groups. The infra‐red absorption spectra of a few groups of unsaturated thioethers are discussed in detail, attention being drawn, among other things, to their resemblance to infra‐red absorption spectra of analogous chlorine compou

ISSN:0165-0513    

DOI:10.1002/recl.19600790909

出版商:WILEY‐VCH Verlag    

年代:1960

数据来源: WILEY

摘要:

AbstractThe preparation of a number of dimethylamino‐azobenzene derivatives of the types I‐IV (see formulae below) is described. The choice of the methods of preparation depends on considerations about steric effects on mesomer

ISSN:0165-0513    

DOI:10.1002/recl.19600790910

出版商:WILEY‐VCH Verlag    

年代:1960

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19600790901

出版商:WILEY‐VCH Verlag    

年代:1960

数据来源: WILEY