Showing papers on "Chemical decomposition published in 1984"
TL;DR: Determination des vitesses de reaction initiales de SiH 4, Si 2 H 6, Si 3 H 8 et H 2 dans des decharges luminescentes de silane as discussed by the authors.
Abstract: Determination des vitesses de reaction initiales de SiH 4 , Si 2 H 6 , Si 3 H 8 et H 2 dans des decharges luminescentes de silane. L'addition de NO inhibe la production de Si 2 H 6 , Si 3 H 8 et des produits solides
96 citations
80 citations
TL;DR: In this article, the authors studied the decomposition of methanol on Ni surfaces using a new technique, temperature programmed pulsed-laser-induced-desorption, which can be used to follow the course of surface reactions below the temperatures required for product desorption.
74 citations
Patent•
05 Mar 1984
TL;DR: Amorphous metal alloy powders are synthesized by solid state decomposition reactions as mentioned in this paper, where at least one precursor compound is thermally decomposed at a temperature below the crystallization temperature of the amorphous metal mixture to be formed.
Abstract: Amorphous metal alloy powders are synthesized by solid state decomposition reactions. At least one precursor compound is thermally decomposed at a temperature below the crystallization temperature of the amorphous metal alloy to be formed. The decomposition product comprises an intimate mixture of the elements of the alloy and, after heat-treating if necessary, exhibits amorphous characteristics.
59 citations
46 citations
TL;DR: In this paper, the electrochemical reduction and catalytic decomposition rates of hydrogen peroxide on passive iron in alkaline solutions have been studied, and a common reduction pathway is proposed, which involves either the coordination of the peroxide ion on a Fe3+ center, followed by reduction on the adsorbed state, or an ECE sequence where the reduction is mediated by surface Fe2+ centres.
45 citations
TL;DR: Constantes de stabilite et vitesses de formation and dissociation des complexes are sensibles a la taille des cations as discussed by the authors, while constantes de vitesse de dissociation sont sensibles.
Abstract: Constantes de stabilite et vitesses de formation et de dissociation des complexes. Les constantes de vitesse de dissociation sont sensibles a la taille des cations
42 citations
TL;DR: In this paper, a discussion des effets des substituants, du solvant et des catalyseurs acides sur la decomposition des ozonides primaires correspondants.
Abstract: Etude de l'ozonolyse du dimethyl-2,3butene-2 et du cis-butene-2, en particulier de la decomposition des ozonides primaires correspondants. Discussion des effets des substituants, du solvant et des catalyseurs acides sur la decomposition des ozonides primaires
39 citations
TL;DR: Les complexes dipeptide-Ni(III) sont des especes a vie longue en solution neutre as mentioned in this paper, i.e. especements violet-noir en complexe jaune.
Abstract: Les complexes dipeptide-Ni(III) sont des especes a vie longue en solution neutre. Spectres RPE. Etude de la transposition catalysee par les acides des especes violet-noir en complexe jaune. Cinetique
38 citations
TL;DR: Les donnees cinetiques montrent que 2 protons sont mis en jeu dans l'etat de transition de la reaction as discussed by the authors, a.k.a.
Abstract: Les donnees cinetiques montrent que 2 protons sont mis en jeu dans l'etat de transition de la reaction. Parametres d'activation
38 citations
TL;DR: In this article, surface metastable quenching electron spectroscopy (MQS) and thermal desorption has been used to study the chemical properties of NO adsorbed on clean Ni(111) or on Ni( 111) precovered with O or N + O.
TL;DR: In this article, the apparent activation energies were determined by the graphical method of Freeman-Carroll, modified forn=1, and Piloyan's two methods from the TG and DTG curves.
Abstract: Thermal studies on tris(N,N-disubstituted dithiocarbamates) of arsenic(III), antimony(III) and bismuth(III) of the type M[S2CX]3 (M=As, Sb, Bi; X=NEt2, N(CH2)4O) by simultaneous TG, DTG and DTA were carried out in air and nitrogen atmospheres. The apparent activation energies were determined by the graphical method of Freeman-Carroll, modified forn=1, and Piloyan's two methods from the TG and DTG curves. The TTN temperatures were calculated from the TG profiles. A possible mechanism of the decomposition reaction is suggested on the basis of the results of their pyrolysis and their mass spectral data. The intermediates obtained at the ends of various decomposition stages were identified via elemental analysis and i. r. and mass spectral data, whereas the residues were identified by X-ray powder diffraction analysis. A dimeric structure of the type M2[S2CN(CH2)4O]4 (M=As, Sb) is proposed.
TL;DR: In this article, an ester type glycosyl linkage of acidic tri- and di-terpenes was selectively cleaved without decomposition of a reducing terminal of the resulting sugar moiety to give an anomeric mixture of methyl glycosides along with an aglycone or a pro-aglycone in quantitative yield.
TL;DR: In this paper, the decomposition of K 4 Ru (CN) 6 par Ce (IV) suivie d'un echange d'ion produit des solutions aqueuses ne contenant que Ru 6 3−, K + et de sulfates.
Abstract: L'oxydation de K 4 Ru (CN) 6 par Ce (IV) suivie d'un echange d'ion produit des solutions aqueuses ne contenant que Ru (CN) 6 3− , K + et de sulfates. Mecanisme de la decomposition spontanee
TL;DR: In this paper, the decomposition of acetic acid derivatives on Ni(111) was examined by TPD and AES and the results showed that acetic acids derivatives react by the same mechanism as formic acid derivatives.
TL;DR: By use of an appropriately substituted phenol, this phenomenon can be exploited to give high yields of phenoxyamines having oxygenated substitution patterns that were unattainable by previous methods.
Abstract: Treatment of phenols with 2,4-dinitrophenoxyamine leads to the synthesis of phenoxyamines through an amine exchange reaction. Yields for this reaction are sensitive to the pK/sub a/ of the phenol in a manner explainable in terms of a competing bimolecular decomposition reaction involving the 2,4-dinitrophenoxyamine. By use of an appropriately substituted phenol, this phenomenon can be exploited to give high yields of phenoxyamines having oxygenated substitution patterns that were unattainable by previous methods.
TL;DR: Constantes de stabilite et vitesses de formation and de dissociation des cryptates alcalinoterreux avec (2, 1, 1), (2 2, 2 B, 2 ) and (2 B,2 B, 2 ).
Abstract: Constantes de stabilite et vitesses de formation et de dissociation des cryptates alcalinoterreux avec (2,1,1), (2,2,1), (2,2,2), (2 B ,2,2) et (2 B ,2 B ,2)
TL;DR: In this article, two mechanisms are proposed, one for exclusive primary process formation of C2H4 and the other for both primary and secondary formation routes, which can be made compatible with the rate and product yield data within experimental errors.
Abstract: The shock-induced thermal decompositions of vinylsilane and vinylsilane-d3 (0.2% on argon) have been studied in the temperature range of 1085–1275 K, and at total pressures of about 3100 torr. In systems without silylene traps, some induced decomposition occurs which is attributed to the silylene chain sequence VSiH C2H2 + SiH2, SiH2 + VSiH3 ⇄ VSiH2SiH3 VSiH2SiH + H2, VSiH2SiH VSiH + SiH2. In the presence of silylene traps (butadiene and acetylene), the overall decomposition kinetics are log k(VSiH3, s−1) = 14.95 − 63,268 cal/2.303RT and log k(VSiD3, s−1) = 15.14 − 64,815 cal/2.303RT. Three primary processes contribute to the decomposition: 1,1-H2 elimination, 1,2-H2 elimination, and ethylene elimination. Two mechanisms are proposed, one for exclusive primary process formation of C2H4, and the other for both primary and secondary formation routes. Modeling studies are reported which show that both mechanisms can be made compatible with the rate and product yield data within experimental errors.
TL;DR: The BF3-catalyzed decomposition of m-and p-substituted α-diazoacetophenones in excess of methyl thiocyanate and ethyl thiocohenate gave the corresponding 2-methylthio-, and 2-ethylthio-5-aryloxazoles, respectively in good yields along with s-alkyl-n-aroylmethylthiocarbamates and α-ethoxyacetophenone as mentioned in this paper.
Abstract: The BF3-catalyzed decomposition of m- and p-substituted α-diazoacetophenones in excess of methyl thiocyanate and ethyl thiocyanate gave the corresponding 2-methylthio-, and 2-ethylthio-5-aryloxazoles, respectively in good yields along with s-alkyl-n-aroylmethylthiocarbamates and α-ethoxyacetophenones. However, yields of 2-dimethylamino-5-aryloxazoles by the reaction of dimethylcyanamide with α-diazoacetophenones were poor. 5-Dimethylamino- or 5-alkoxy-4-aryl-2-methyloxazoles were prepared by the reaction of N,N-dimethyl-α-(p-nitrophenyl)diazoacetamide or alkyl aryldiazoacetates with nitriles. When ethyl phenyldiazoacetate or methyl p-chlorophenyldiazoacetate were used, ketazines of alkyl arylglyoxylates were obtained together with oxazoles.
TL;DR: In this paper, the adsorption and decomposition of ammonia over magnesium oxide have been studied by means of infrared spectroscopy, and the decomposition proceeds at 573 K to form N2 and H2.
Abstract: The adsorption and decomposition of ammonia over magnesium oxide have been studied by means of infrared spectroscopy. The decomposition of ammonia proceeds at 573 K to form N2 and H2. The following mechanism of decomposition of ammonia over MgO has been elucidated: [graphic omitted].
TL;DR: In this paper, the generation of nitrosyl compounds NOX in chlorinated hydrocarbons as inert organic media is described, which serves as a convenient in-situ-method to generate nitro-syls compounds.
Abstract: Generation of Nitrosyl Salts in Dry Organic Media
Trimethylsilyl halides (CH3)3SiX (2a – c, X Cl, Br, I) are sufficiently electrophilic to cleave, in an equilibrium reaction, alkyl nitrites O NOR (1a, b, R i-C5H11, C2H5) with formation of O NX (3a – c) and (CH3)3SiOR (4a, b). This reaction serves as a convenient in-situ-method to generate nitrosyl compounds NOX in chlorinated hydrocarbons as inert organic media.
TL;DR: On etudie les decompositions des triazenes R−N=N−NR'R'' (R=R'=C 4 H 9, R''=CH 3 ; R´=R''=C 2 C 2 H 5 ) as discussed by the authors.
Abstract: On etudie les decompositions des triazenes R−N=N−NR'R'' (R=R'=C 4 H 9 , R''=CH 3 ; R=R'=R''=CH 3 ; R=R'=CH 3 , R''=COCH 3 ; R=R'=CH 3 , R''=CO 2 C 2 H 5 )
TL;DR: Preparation des complexes (η-C 5 Me 5 )Ru(CO) 2 CHO et ( η -C 5 ME 5 ) Ru(CO),PMe 2 Ph)CHO et mecanisme de leur decomposition as mentioned in this paper.
Abstract: Preparation des complexes (η-C 5 Me 5 )Ru(CO) 2 CHO et (η-C 5 Me 5 )Ru(CO)(PMe 2 Ph)CHO et mecanisme de leur decomposition
TL;DR: In this article, a two-step peroxide decomposition mechanism is proposed, which is strictly dependent on the continuous presence of carbon dioxide, but not of carbonate anions, in the peroxide solutions.
Abstract: Rapid hydrogen peroxide decomposition in aerated alkaline solutions is described, the maximum rate being attained at pH values between 11.5 and 11.7, where the peroxide (pKa= 11.7) is ca. 50% unprotonated. The reaction proceeds with the release of protons and is strictly dependent upon the continuous presence of carbon dioxide, but not of carbonate anions, in the peroxide solutions. The following two-step mechanism is proposed: (1) formation of percarbonic acid (H2CO4) by condensation of CO2 with the undissociated peroxide (H2O2) and (2) reduction of the acid by perhydroxyl anions (HO–2).
TL;DR: In this paper, the authors showed that the ethylene ligand does not rotate in solution up to 120°C and 13C NMR studies indicate a configuration for Cp2Ta(C2H4)H in which the CC axis lies in the symmetry plane of the molecule.