摘要:

AbstractThe vapour phase (thermal) reaction of arenes (benzene, chlorobenzene, benzonitrile) with molecular chlorine ‐ setting in at roughly 250° ‐ can be made to occur even below 200° by adding small proportions of CCl3‐SO2‐CCl3(“S”). Products (chlorinated arenes) and relative rates are highly comparable under both sets of conditions. Depending oninter alia, the concentration of S in the feed, from a few to well over 2000 moles of product per mole of S are formed.Both modes of reaction are interpreted as radical chain processes, chlorine atoms ‐ and their arene adducts ‐ being intermediates. In the initiated reactions. S is thought to form CCl3radicals, which lead to chlorine atoms by

ISSN:0165-0513    

DOI:10.1002/recl.19710900702

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractThe characterization of double bonds by the difference between thecisandtransshielding effects of alkyl groups upon the PMR chemical shifts of the ‐allylic protons is described. Application of the principle is demonstrated for 2‐unsaturated aldehydes, acetals, alcohols and ethers. Results at 220 MHz on three geometrical isomers of 5,8,11,14‐eicosatetraenoic acid show that it is even possible to characterize double bonds in polyunsaturated fatty

ISSN:0165-0513    

DOI:10.1002/recl.19710900703

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractHydrogenated 1‐methylallyldicyclopentadienyltitanium(III) in hydrocarbon solution is an active homogeneous catalyst for the hydrogenation of unsaturated hydrocarbons at room temperature. 1,3‐Dienes are not hydrogenated to completeness if they are capable of formingsyn,syn‐1,3‐dialkyl‐substituted allyl complexes with the catalyst. 1‐Alkynes are not hydrogenated but polymerize rapidly totrans‐polyacetylenes. In the absence of hydrogen, 1,5‐cyclo‐octadiene is isomerized to the 1,3‐isomervia1,4‐cyclo‐octadiene. Small amounts of hydrogen promote this double bond migration. 1‐Alkenes are converted selectively into 2‐alkenes at room temperature in a few minutes. Initially, thetrans‐isomer is formed preferentially, followed by a

ISSN:0165-0513    

DOI:10.1002/recl.19710900704

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractThe applicability of the Berthelot, the Guggenheim‐McGlashan, the Pitzer‐Curl, the McGlashan‐Potter, and the Kreglewski virial equation to gas imperfection calculations has been examined empirically. For this purpose, calculated virial coefficients were compared with experimental data for a number of normal and branched alkanes, some polymethylenes, some aromatic and halogenated hydrocarbons, and e

ISSN:0165-0513    

DOI:10.1002/recl.19710900705

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractThe ESR spectra of the radical anions of 9. 10‐dihydrophenanthrene. 4.5‐ dihydropyrene. 9.1 0‐dihydroanthracene and 5.12‐dihydrotetracene have been measured and interpreted. Additional information on the hyperfine splitting constants has been obtained from a NMR study of the electron transfer reaction between the paramagnetic anions and the diamagnetic parent molecules.A kinetic process due to inversion of the molecular conformation in 9.10‐ dihydrophenanthrene has been studied quant

ISSN:0165-0513    

DOI:10.1002/recl.19710900706

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractA convenient synthetic procedure is described for the preparation of triphenoxymethanes from aryl dichloromethyl ethers1and sodium phenolates in dimethoxyethane.

ISSN:0165-0513    

DOI:10.1002/recl.19710900707

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractAn oxidative reaction is described by which toluene is converted into benzene. The reaction is catalyzed by bismuth uranate. Selectivities up to 70% are obtained if toluene vapour reacts with the catalyst without gaseous oxygen being present; the catalyst becomes partially reduced, but can easily be reoxidized afterwards with air. Biphenyl and benzaldehyde have been identified as by‐product

ISSN:0165-0513    

DOI:10.1002/recl.19710900708

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractThe absolute configuration of optically active 2‐ethylpiperidine has been established both by chemical correlations and by optical rotatory dispersion measurements. The (+)‐compound has theS‐configuration.The ORD of 2‐ethyl‐1‐nitrosopiperidine is discussed in connection with a sector rule forN‐

ISSN:0165-0513    

DOI:10.1002/recl.19710900709

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractSecond‐order rate constants,k2, of reactions of thiolates with several 1‐aryl‐2‐halogenoacetylenes and 1‐halogeno‐2‐(2‐thienyl)acetylenes were measured in methanol‐water mixtures. Formeta‐ andpara‐substituted 1‐bromo‐2‐phenyl acetylenes these rate constants correlate well with Hammett σ constants: p 1.15. Linear correlations were observed between logk2and pKaof the corresponding thiols.The nucleophilicity constants,n, for substitution on bromine and iodine appear to be quite different from those for substitution on other atoms like carbon, sulfur and platinum. It was possible to correlate all the rate constant withEandHin

ISSN:0165-0513    

DOI:10.1002/recl.19710900710

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractThe preparation and PMR investigation of some specifically deuteratedt‐butylcyclohexanes is reported. The chemical shifts of the various ring protons and the vicinal axial‐equatorial coupling constants have been determined accurately. The coupling constants show that an equatorialt‐butyl group distorts the chair conformation of cyclohexane: thet‐butyl side of the ring is somewhat puckered. The chemical shifts of the ring protons oft‐butylcyclohexane differ from those of cyclohexane. In consequence the use of at‐butyl group as a holding group in conformational analysis is not always justified.A long range coupling of 1.4 Hz is observed between 1,3‐diequatorial ring protons. This partly explains the complexity of the spectra of apparently simple spin systems of other cyclohexane derivatives.The dehydration of 3‐t‐butylperdeuterocyclohexanol using D3PO4gives rise to a mixture of the threet‐butylperdeuterocyclohexenes. The intermediate formation of a protonated four‐membered ring is proposed in order to explain the presence of deuterium in thet‐butyl group of only 1‐t

ISSN:0165-0513    

DOI:10.1002/recl.19710900711

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY