Showing papers on "Bromine published in 1975"

The chemistry of atmospheric bromine

Abstract: Bromine may act as a catalyst for recombination of ozone and could be more efficient than either nitric oxide or chlorine. The lower atmosphere contains small concentrations of gaseous bromine produced in part by marine activity and volatilization of particulate material released during the combustion of leaded gasoline, with an additional contribution due to the use of methyl bromide as an agricultural fumigant. Observations by Lazrus et al., (1975) indicate small concentrations of bromine, about 10 to the -11th power (v/v), in the contemporary stratosphere and appear to imply a reduction of approximately 0.3% in the global budget of O3. Estimates are given for future reductions in O3 which might occur if the use of CH3Br as an agricultural fumigant were to continue to grow at present rates.

Reactive ion etching of aluminum

Abstract: A process for etching aluminum wherein a masked layer of aluminum, supported on a substrate, is exposed to a plasma formed by imposing an RF voltage across at least two spaced electrodes in an ambient including a gas selected from the group consisting of CCl4, Cl2, Br2, HCl. The resultant conditions provide a reactive environment where the aluminum is bombarded with chlorine or bromine ions. The aluminum reacts with chlorine or bromine ions to form an aluminum chloride or bromide compound, which is volatile at the temperature of the sputtered substrate.

Vacuum ultraviolet absorption spectra of the bromomethanes

Abstract: The vapor phase vacuum ultraviolet absorption spectra of methyl bromide, methylene bromide, bromoform, and carbon tetrabromide are reported for the region 40 000−90 000 cm−1 (250−110 nm) Many of the Rydberg and intravalent absorptions of the bromine electrons in the nonbonding p orbitals, which are perpendicular to the C−Br bonding axes, and the σ*←σ (C−Br) absorptions of the compounds have been assigned A correlation of the molecular Rydberg series of methyl bromide to series in krypton, which has made possible the assignment of the 4d and 4f Rydberg absorptions, is presented Expanded vibrational progressions of the first ns and np Rydberg transitions of methylbromide are presented The analysis of these progressions indicates that transitions to the 5s and 5p Rydberg orbitals bring about a Jahn−Teller distortion of the molecule Three ns Rydberg series of methylene bromide were assigned which converge on the ionization potentials of 10629±0010, 10839±0010, and 11261±0010 eV The states formed u

Daunomycin analogues, their preparation and use

Abstract: Daunomycin analogues of the formula: ##STR1## wherein when each R 1 is hydrogen, each R is hydrogen, chlorine, bromine, methyl or methoxy and when each R 1 is chlorine, bromine or methyl, each R is hydrogen, are useful in treating various mammalian tumors and are prepared by reacting a daunomycinone derivative of the formula: ##STR2## wherein R and R 1 are as defined above with 1-chloro-2,3,6-trideoxy-3-trifluoroacetamido-4-trifluoroacetoxy-α-L-lyxopyranose in an inert anhydrous organic solvent in the presence of a catalyst and a hydrogen chloride acceptor.

Activation of water soluble amines by halogens for trapping methyl radioactive iodine from air streams

Abstract: Gas adsorbent charcoals impregnated with an aqueous solution of the reaction product of a tertiary amine and elemental iodine or bromine are better than 99 per cent efficient in trapping methyl iodine 131 . The chemical addition of iodine or bromine to the tertiary amine molecule increases the efficiency of the impregnated charcoal as a trapping agent, and in conjunction with the high flash point of the tertiary amine raises the ignition temperature of the impregnated charcoal.

N-substituted tetrahalophthalimides as flame retardants

Abstract: Disclosed are novel compounds of the formula ##STR1## WHEREIN EACH X is independently selected from chlorine or bromine, R is alkylene having from 1 to 6 carbon atoms, each R' is independently selected from an alkyl or haloalkyl group having from 2 to 6 carbon atoms, and n is 1 to 3. The above compounds are effective flame retardants in flammable polymeric compositions.

Determination of the bromide space in man by fluorescent excitation analysis of oral bromine.

Abstract: The bromide dilutional volume determined by intravenous administration of 82Br has been compared with the corresponding volume determined by oral administration of stable bromide in 11 patients with various medical disorders. Stable bromide was assayed by fluorescent excitation analysis using a 109Cd source and a lithium-drifted silicon detector. The average deviation between the fluorescent and the radiobromide dilutional volumes was 4.2% with a standard deviation of ±8.5%. This substantiates both the accuracy of the fluorescent excitation method as applied to this tracer and the validity of utilizing oral tracer administration in comparison with intravenous administration. The derived estimates of extracellular fluid volume averaged 28.7% of body weight in the entire group of 11 patients and 25.8% in the 4 normal subjects included in the group. Evaluation of the extracellular fluid space utilizing fluorescent excitation of stable bromide permits high statistical accuracy of sample measurement with great simplicity compared with current chemical methods and with avoidance of the patient radiation exposure associated with 82Br.

Stabilized non-medical fungicidal, bactericidal and algicidal composition

Abstract: A halocyanoacetamide compound having the formula: ##STR1## wherein X is a halogen such as Cl, F, Br and I; Y represents a halogen such as chlorine, fluorine, bromine and iodine or hydrogen atom; and R represents a hydrogen atom or a lower alkyl group containing from 1 to 8 carbon atoms, is stabilized with an organic carboxylic acid or a diol.

Flame-retardant resinous compositions containing trihaloneopentyl haloalkyl phosphates

Abstract: Flame-retardant resinous compositions comprise an organic polymer and a phosphate that has the structural formula ##STR1## wherein each X represents bromine or chlorine; R represents haloalkyl having 2 to 4 carbon atoms and 1 to 5 bromine and/or chlorine atoms, phenyl, or trihaloneopentyl; and R' represents haloalkyl having 2 to 4 carbon atoms and 1 to 5 bromine and/or chlorine atoms.

Bis-(tetrahalophthalimidocarbonyl)-benzene

Abstract: This invention discloses chemical compounds of the formula ##STR1## wherein X is chlorine or bromine and each of Y1, Y2, Y3 and Y4 are hydrogen, chlorine or bromine. Further disclosed are combustible polymers which have incorporated therein a fire retardant amount of a compound of the foregoing description.

α,β-Unsaturated Carboxylic Acid Derivatives. VIII. The Synthesis and Reaction of Esters N-Acyl-N-bromo-α-dehydroamino Acid

Abstract: The addition of bromine to t-butyl 2-(N-acylamino)-2-alkenoate (3) was accompanied by the elimination of hydrogen bromide and the decomposition of the ester group to give 2-(N-acylamino)-3-bromo-2-alkenoic acid, while the bromination of 3 with NBS gave the corresponding N-bromo derivative (7), whose bromine atom gradually migrates to give t-butyl 2-(N-acylamino)-3-bromo-2-alkenoate. The substitution of the bromine of 7 with nucleophiles gave, successively, the corresponding N-methoxy, N-benzyloxy and N-cyano derivatives, while that with sodium azide gave the corresponding migration products. The structures of the new compounds were assigned.

Method for dehalogenating aromatic compounds

Abstract: Dehalogenation of water-immiscible or sparingly soluble aromatic compounds containing chlorine or bromine by contacting with an aqueous solution of a formic acid salt in presence of a hydrogenation catalyst and a surface active agent.

Pentacovalent intermediate in the Arbuzov reaction

Abstract: Direct evidence by 31P-n.m.r. spectroscopy is presented for the formation of a five-co-ordinate intermediate in the Arbuzov reaction of tervalent phosphorus esters with elemental chlorine or elemental bromine and benzenesulphenyl chloride.

Dis-azo pigments deriving from bis-diazotized diamino-2-phenyl-benzazolones

Abstract: Pigments of the general formula ##STR1## wherein x is sulfur, oxygen or --NR--, R is hydrogen or alkyl of 1 to 4 carbon atoms, A is ##STR2## Y 1 , Y 2 , Z 1 , Z 2 , Z 3 , Z 4 , Z 5 , Z 6 and Z 7 are hydrogen, chlorine, bromine, methyl, ethyl, methoxy or ethoxy. These new disazo pigments can be used in all fields of dyeing where pigments are typically used. They are distinguished by improved fastness properties and tinctorial strength.

Haloacetanilides as microbicidal active substances

Abstract: Compounds of the formula ##STR1## wherein Z 1 represents methyl or chlorine, Z 2 represents chlorine or bromine, Z 3 represents hydrogen or C 1 -C 3 alkyl, and X represents fluorine, chlorine, bromine or iodine, exhibit microbicidal activity, preferably against phytopathogenic fungi.

The oxidative cyclization of formazans to tetrazolium salts

Abstract: Bromine oxidizes 1,3,5-triarylformazans (1) quantitatively to the corresponding 2,3,5-triaryltetrazolium salts (2) in methanol or aqueous acetic acid. The reaction is ionic and is markedly aided by electron donation in the aryl rings. In methanol containing 0·1M-sodium bromide (at 25°) substituents in the C-aryl ring give a ρ value of –1·40, while those at N-1 and -5 give ρ–1·10 and –2·42. A mechanism of oxidation is proposed involving electrophilic attack by bromine at carbon and formation of a covalent intermediate, followed by unimolecular C–Br bond cleavage to yield the tetrazolium salt.

Synthesis of 1H-4,1,2-benzothiadiazines from substituted N-acetyl-N-aryl-N′-thioaroylhydrazines

Abstract: Treatment of N-acetyl-N-aryl-N′-thioaroylhydrazines, in which the N-aryl group is 2,4-disubstituted, with triethylamine in refluxing acetonitrile gives 6-substituted 1-acetyl-3-aryl-1H-4,1,2-benzothiadiazines in cases where the displaceable 2-substituent is bromine, fluorine, or iodine and the 4-substituent is electron-attracting; the synthesis fails when the 2-substituent is chlorine.

A Convenient Synthesis of α-Bromophenylacetic Acid from Benzaldehyde Using Methyl (Methylthio) methyl Sulfoxide

Abstract: 1-Methylsulfmyl-1-(methylthio)-2-phenylethylene (2a) and 1-methylsulfinyl-1-(methylthio)-2-(p-chlorophenyl)ethylene (2b) reacted with bromine in various solvents to give α-bromophenylacetic acid derivatives. It should be noted that α-bromophenylacetic acid and α-bromo(p-chlorophenyl) acetic acid were mainly obtained by the reaction of bromine with 2a and 2b, respectively, in acetic acid.