A product study of p-xylene oxidation by the Co-Br-Py catalytic system has been investigated under anaerobic conditions at 120 °C. It was shown that in bromine-free systems the direct oxidation of p-xylene by Co(III) ions proceeds, while the distribution and yield of reaction products are only slightly influenced by the type of solvent. During the simultaneous oxidation of p-xylene and p-toluic acid in aqueous systems, the latter increases the selectivity of reaction: however, the methyl group of p-toluic acid is not attacked by Co(III) ions. In the presence of bromine compounds, p-xylene is attacked by bromine species formed by the preferred reaction of Co(III) with bromide ions. In contrast to reaction in acetic acid, in the aqueous system brominated products are formed to a lesser extent.

Kinetics, selectivity and product yields of the oxidative condensation of 2-mercaptobenzothiazole with cyclohexylamine have been studied using a copper catalyst and molecular oxygen as the oxidizing agent. The reaction rate increases linearly with catalyst concentration and oxygen pressure, and is independent of thiol concentration. The value of the rate constant at 75 °C is k = (5.4 ± 0.1) × 10−3s−1 atm−1 and the apparent activation energy 56.1 ± 5.1 kJ mol−1. It is assumed that the rate of reoxidation of cuprous ions controls the overall process and that the catalytically active sites are copper complexes coordinated by thiolate ligands.

Abstract13C NMR chemical shifts and 13C‐31P coupling constants of fourteen derivatives from 3,9‐di(alkylphenoxy)‐2,4,8,10‐tetraoxa‐3,9‐diphosphaspiro[5.5]undecane and of eight derivatives of the 3,9‐dioxo type are reported. All investigated compounds possess a chair conformation with the lone pair or the phosphoryl oxygen in the equatorial position. The alkylphenoxy groups are in a cis position with respect to the lone pair or the phosphoryl oxygen. Conformational changes about the arylO bond can be monitored via 31POC13C couplings and their angular dependence was found to be non‐symmetric.

Cumene hydroperoxide has been shown to react with bis-(1,2-diphenylethylene-1, 2-dithiolato)nickel in cumene solution at 40 – 60°C via a twostage process. Cumylperoxy radicals generated in the first radical step oxidize the sulphur atoms of the dithiolate ligands leading to destruction of the nickel complex and formation of 1,2-diphenylacetylene, benzoic acid and sulphur oxides, probably sulphur dioxide and H2SO4. In the second stage, these acidic compounds decompose the main part of the hydroperoxide to phenol via an ionic process.

Formation of anion radicals [RCOCHCOR'] - with R ≡ R' = Me, i-Pr, t-Bu, and with R = Me, R' = Ph has been observed in reactions of beta diketonates wih Grignard reagents. The splitting constant of the methine proton is 0.26 mT, and that of the methyl protons is 1.2 mT if R ≡ R' = Me. According to INDO calculations the anion radical is stabilized with Ni 2+ counterion in tetrahedral arrangement.

physica status solidi (a)Volume 80, Issue 2 p. K167-K170 Short Note New aspect of ultrasonic detection of some significant structural parameters of amorphous SeTe alloys P. Koštial, P. Koštial Department of Physics, Technical University of Transport and Communication Engineering, Žilina Search for more papers by this authorL. Malík, L. Malík Department of Physics, Technical University of Transport and Communication Engineering, Žilina Search for more papers by this authorL. Both, L. Both Meopta, Bratislava Search for more papers by this author P. Koštial, P. Koštial Department of Physics, Technical University of Transport and Communication Engineering, Žilina Search for more papers by this authorL. Malík, L. Malík Department of Physics, Technical University of Transport and Communication Engineering, Žilina Search for more papers by this authorL. Both, L. Both Meopta, Bratislava Search for more papers by this author First published: 16 December 1983 https://doi.org/10.1002/pssa.2210800249 Velký Diel, 01088 Žilina, CSSR. Meopta, Hagarova 9, 83402 Bratislava, CSSR. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Volume80, Issue216 December 1983Pages K167-K170 RelatedInformation

Metal polyphthalocyanines enhance the rate of cumene oxidation and decrease the selectivity to cumene hydroperoxide. Formation of cumyl alcohol as main by-product depends on the initial rate of oxidation or reaction time.

AbstractDurch Einwirkung von Peroxidradikalen oder Hydroperoxiden wie z.B. (II) gehen die Hydroxylamine (I) in die Nitroxylradikale (III) über, die zu den Spin‐Addukten (IV) weiteroxidiert werden.

The products of oxidation of 3-pentanone and 2-pentanone by thallic sulphate in dilute sulphuric acid have been identified and determined by nuclear magnetic resonance, gas chromatography—mass spectrometry and gas—liquid chromatography (GLC). α-Hydroxyketones were identified as the main oxidation products and the contents in the reaction mixture were determined by GLC using an internal standard. The optimum conditions for GLC were found experimentally and the maximum relative error of the determination of these compounds was ± 1%.

Hydroxyperoxides and cobalt-coordinated peroxy-radicals oxidize hydroxyolamines as e.g. Et2NOH, (PhCH2)2NOH, PhCH2PhNOH to the respective nitrones, and the spin adducts - nitrone and peroxy-radical - are formed. In contrast to hydroxyperoxides the coordinated peroxy radicals can oxidize the formed spin adduct, the methylene or methine groups next to nitrogen being converted into carbonyl groups. The radical intermediates corresponding to individual steps of the gradual oxidation have been identified by means of EPR spectra.

AbstractIn the reactions of meta‐ and para‐alkyl substituted benzoic acids with aryl Grignard reagents, in tetrahydrofuran solutions and in the presence of nickel salts, the ESR spectra of the anion radicals of carboxylates derived from the benzoic acids were observed which represent the intermediates in the formation of ketyl radicals.

AbstractIn the reactions of alkyl‐substituted‐benzenecarboxylic and ‐2‐hydroxybenzenecarboxylic acids (ArCOOH) with alkyl‐substituted phenyl Grignard reagents (RMgX) in the presence of nickel, ketyl radicals ArCO−R are formed. The para substituents (H, Me, Et, Isopr and t‐Bu) of R increase the non‐equivalence of its ortho protons (a change of a2H = 0.43 mT, a6H = 0.422 mT to 0.435 mT, 0.395mT respectively, on substituting t‐butyl for H at position 4). The oxido anion group originating from 2‐hydroxybenzenecarboxylic acid has a strong push effect and nearly doubles the unpaired spin density on the phenyl ring R.

Chemischer InformationsdienstVolume 12, Issue 10 Preparative Organic Chemistry ChemInform Abstract: FORMATION OF PARAMAGNETIC PRODUCTS IN REACTIONS OF ORGANOMETALLIC COMPOUNDS. PART XI. ANION RADICALS OF ALKYL-SUBSTITUTED DIBENZOTHIOPHENE SULFONES A. STASKO, A. STASKOSearch for more papers by this authorL. MALIK, L. MALIKSearch for more papers by this authorA. TKAC, A. TKACSearch for more papers by this authorP. PELIKAN, P. PELIKANSearch for more papers by this author A. STASKO, A. STASKOSearch for more papers by this authorL. MALIK, L. MALIKSearch for more papers by this authorA. TKAC, A. TKACSearch for more papers by this authorP. PELIKAN, P. PELIKANSearch for more papers by this author First published: March 10, 1981 https://doi.org/10.1002/chin.198110156AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume12, Issue10March 10, 1981 RelatedInformation

Durch die Dehydrocyclisierung von 4,4'(H-, Et-, i-Pr-, t-Bu-)-diphenylsulfonen entstehen Anionradikale der 3,6(dialkylsubstituierten)-Dibenzothiophensulfone. Mit Hilfe der ESR-Spektroskopie wurden folgende Aufspaltungskonstanten ermittelt: a^'' ~ 0,02 ... 0,05 mT, ~ 0,3 m T und oft*"* ~ 0,2 (<0,2) mT. Die Bestimmung der Ladung und der Spindichteverteilung dieser Radikale sowie die Zuordnung ihrer Aufspaltungskonstanten erfolgte auf G r u n d von Alkylsubstitution und INDO-Berechnungen.