Reactions of organogermanium derivatives of mercury with bromine

Conclusions The bromination of bis(triisopropylgermyl)mercury by bromine gives a high yield of triisopropylgermylmercury bromide. It was found that triisopropylgermylmercury bromide and other compounds of this type reduce HgX₂ to Hg₂X₂ (X=halide).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 927–929, April, 1986.     

Reactions of bromine and chlorine with osmium hexafluoride

Osmium hexafluoride combines with bromine to form Br₂OsF₆. Solutions of OsF₆ in liquid chlorine are strongly blue or blue violet in colour, and charge transfer interactions are indicated.     

Halogenation of unsaturated esters—III : Reactions of bromine chloride with chlorinated methyl 2-butenoates

Additions of Cl₂, Br₂; and BrCl to methyl Z-2-chloro-2-(1), E-3-chloro-2-(2), Z-3-chloro-2-(3) and E-4-chloro-2-butenoates (4) in CCl₄ both in the dark and light have been investigated. The product compositions are compared with those reported previously for methyl monochloropropenoates. The chlorine substitution was found to affect the product distributions in the reactions with the BrCl reagent. Under the ionic conditions Br₂ adducts were the main products from 1 and 2, whereas 3 reacted like methyl Z-3-chloropropenoate giving only negligible amount of the Br₂ addition. The Cl₂ addition amounted, as in the reactions of methyl monochloropropenoates, to only a few percent. Compared with the parent esters the chlorine substitutions in 2, 3 and 4 also affected the regiochemistry of the BrCl addition. The main regioisomer in the dark, i.e. the 2-bromo-3-chloro adduct, was obtained from 3, as from methyl Z-3-chloropropenoate, with almost complete regioselectivity. Compound 4 also showed greater regioselectivity than methyl E-2-butenoate. Substrate 2 was, however, found to produce more 3-bromo-2-chloro adduct than the unchlorinated parent ester. Mechanisms presented for the additions of BrCl to methyl 3-chloropropenoates are reconsidered on the basis of the results from the present study.     

Oxidation of N-alkyl-N''-tosylhydrazines with bromine

Oxidation of N-alkyl-N'-tosylhy”razines with bromine yield alkyl bromides, vicinal alkyl dibromides and traces of alcohols. The main products of primary hydrazines are monobromides whereas secondary hydrazines preferably produce dibromides. The reaction proceeds with evolution of nitrogen and hydrobromic acid and by the formation of intermediate sulfinic ester which may be isolated. Various substrates were examined under different conditions to confirm the validity of the reaction mechanism hypothesized.     

Reaction of chlorine with bromine

Different possible mechanisms for the gas phase reaction of formation of bromine chloride from bromine and chlorine are discussed. The rate of the reaction has been deduced from photometric measurements in conventional static reactors of surface-to-volume ratio ranging between 0.6 and 3 cm^?1, at temperatures between 51 and 113°C. Experimental data show that (1) the observed reaction is predominantly heterogeneous, and (2) the homogeneous reaction must proceed by an atomic chain mechanism initiated by Br atoms.     

Reactions of 2-phospholene 1-oxides with bromine in some media: Facile preparation of bromohydrin derivatives of 2-phospholenes

Reactions of 1-phenyl- and 1-methoxy-2-phospholene 1-oxides with bromine in aqueous organic solvents or in a protic medium, such as methanol, easily afforded the corresponding 2-bromo-3-hydroxy- or 2-bromo-3-methoxyphospholane 1-oxide derivatives. The reaction mechanism was postulated based on the stereochemistry of the products.     

Products of tetramethyllead dealkylation with bromine

Products of tetramethyllead dealkylation with bromine in the temperature interval from ?20 to 20°C were analyzed by X-ray diffraction, IR spectroscopy, and spectrophotometry. Specific features of their thermal behavior were studied by differential thermal analysis and mass spectrometry.     

Reactions of 3-isopropenyltropolones with bromine and N-bromosuccinimide: Formation of 8H-cyclohepta[b]furan-8-one derivatives

3-Isopropenyltropolones 1a-c were treated with bromine in carbon tetrachloride to give 3-methyl-8H-cyclohepta[b]furan-8-ones 2a-c and their corresponding 7-bromo-substituted compounds 3a-c , while reactions in acetic acid gave the bromo-substituted compounds 3a-c . On the other hand, bromination of 1a-c with N-bromosuccinimide afforded 7-bromo-3-(2-bromo-1-methylethenyl)tropolones 5a-c . The compound 2a was treated with bromine to give 2-bromo-3-methyl-8H-cyclohepta[b]furan-8-one ( 4 ). The tropolones 5a-c were heated in the presence of potassium carbonate to give the cyclized compounds 3a-c .     

Reaction of ethyl o-benzoylenephosphite with bromine

Conclusions The reaction of ethyl o-benzoylenephosphite with bromine proceeds by the scheme of the Arbuzov reaction to give the acid bromide of ethyl-o-bromoformylphenylphosphoric acid, which then decomposes to ethyl bromide and the acid bromide of o-benzoylenephosphoric acid.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 437–439, February, 1971.     

Reactions of recoil38Cl atoms with CCl4 and C6H5Cl: Effect of high electron density scavengers

Reactions of recoil³⁸Cl atoms with CCl₄ and C₆H₅Cl have been studied in presence of various high electron density scavengers. Relative reactivities of recoil³⁸Cl towards the two components of these mixtures are determined using the model proposed by Urch.     

Reactions of derivatives of 4a,9-diaza-1,2,4a,9a-tetrahydro-6H-fluorene with nucleophilic reagents and bromine

The reaction of quinone mono- and diimines of the 4a,9-diaza-12,4a,9a-tetrahydro-6H-fluorene series with aniline and thiophenol gives the corresponding 7-monosubstituted derivatives; with o-phenylenediamine and o-aminophenol the corresponding 6,7-annellated products are formed. Methylenequinone imines of this series, and also the 7,8-benzannellated analogs ofdiazahydrofluorenes, do not react with these nucleophiles. The bromination of diazahydrofluorene derivatives involves both the quinoid system and the enamine fragment.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 982–989, July, 1991.     

Coulometric titration of deactivated phenols with bromine

A number of deactivated phenols containing fluorine, chlorine or bromine, formyi, acetyl, carboxyl or nitro groups have been titrated with anodically generated bromine. The reaction was carried out in a water-acetic acid-pyridine medium and the reactivity was controlled by varying the water and pyridine content and the concentration of bromide ion. Hydrogen in all free positions ortho and para to the phenolic hydroxyl group is generally exchanged for bromine, but in certain instances a partial bromination is possible. The method as developed is widely applicable for deactivated phenols. Only certain ortho-substituted phenols could not be quantitatively titrated. The mean relative error for the phenols titrated was ± 1·2%.     

Investigating polymer blend miscibility with forward recoil spectrometry

We tested forward recoil spectrometry (FRES) as a method to determine miscibility by measuring coexistence compositions in binary polymer blends. In this study, equilibrium phase compositions were determined for a compositionally symmetric poly(styrene‐ran‐methyl methacrylate) random copolymer (S_0.49‐r‐MMA) and two homopolymers, deuterated polystyrene (dPS) and deuterated poly(methyl methacrylate) (dPMMA). Sample preparation, film dewetting, and beam damage were addressed, and the results for these polymer blends were in good agreement with those obtained through other experimental techniques. Deuteration had a strong effect on the miscibility of the dPS/S_0.49‐r‐MMA and dPMMA/S_0.49‐r‐MMA blends, to the extent that the asymmetric miscibility observed separately for the PS/S_0.49‐r‐MMA and PMMA/S_0.49‐r‐MMA blends was not found. Although this deuteration effect may limit the applicability of FRES for some polymer systems, the accuracy with which phase compositions can be determined with FRES makes it an attractive alternative to other less quantitative methods for investigating blend miscibility. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 1547–1552, 2000