Decomposition of tetramethyl-2-tetrazene under acidic conditions

1978 ◽  
Vol 56 (12) ◽  
pp. 1657-1667 ◽  
Author(s):  
Leon J. Madgzinski ◽  
K. Somasekharen Pillay ◽  
Hervé Richard ◽  
Yuan L. Chow
Keyword(s):  
Thermal Decomposition ◽  
Sulfuric Acid ◽  
Trifluoroacetic Acid ◽  
Cation Radical ◽  
Major Product ◽  
Product Analysis ◽  
Aromatic Substrates ◽  
Acidic Conditions ◽  
Olefinic Double Bond ◽  
Relationship Of

Decompositions of tetramethyl-2-tetrazene (TMT) under acidic conditions were investigated by product analysis and by nmr and esr spectroscopic monitors. Photolysis in acetonitrile containing trifluoroacetic acid generated the dimethylaminium radical which added efficiently to an olefinic double bond. Some adducts contained a (CH3)2NCH2— moiety, the immediate precursor of which could be CH2=N(CH3)2+ species. Photolytic addition of TMT to nor-bornenes generated 2-norbornyl radicals that underwent coupling through the exo or endo side to give the dimers. Thermal decomposition in sulfuric acid in the presence of toluene gave N,N-dimethyltoluidines, N-methylphenethylamine, benzyltoluenes, and a plethora of other minor products in addition to a large amount of formylidene methylamine. The last compound was the major product when thermal decomposition of TMT was carried out in trifluoroacetic acid in the presence of toluene or anisol; amination products of aromatic substrates were low and contained only ortho and para isomers. TMT dissolved in these solvents exhibited the esr signal of the stable [Formula: see text] (the tetrazene cation radical) which did not react with cyclohexene. In concentrated sulfuric acid, TMT was decomposed in less than 15 min giving formylidene methylamine and dimethylamine as shown by nmr. In trifluoroacetic acid, the esr signal of tetramethylhydrazine cation radical [Formula: see text] emerged after the TMT solution was irradiated; no dimethylaminium radical signal could be detected. The relationship of [Formula: see text] and [Formula: see text] with formation of the observed products remains unclear.

scholarly journals Thermal decomposition of tris(O-ethyldithiocarbonato)-antimony(III)—a single-source precursor for antimony sulfide thin films

2021 ◽  
Author(s):  
Jako S. Eensalu ◽  
Kaia Tõnsuaadu ◽  
Jasper Adamson ◽  
Ilona Oja Acik ◽  
Malle Krunks
Keyword(s):  
Thin Films ◽  
Thermal Decomposition ◽  
Mass Loss ◽  
Solid Phase ◽  
Evolved Gas Analysis ◽  
Gas Analysis ◽  
Thermal Decomposition Mechanism ◽  
Product Analysis ◽  
Gaseous Species ◽  
Single Source Precursor

AbstractThermal decomposition of tris(O-ethyldithiocarbonato)-antimony(III) (1), a precursor for Sb2S3 thin films synthesized from an acidified aqueous solution of SbCl3 and KS2COCH2CH3, was monitored by simultaneous thermogravimetry, differential thermal analysis and evolved gas analysis via mass spectroscopy (TG/DTA-EGA-MS) measurements in dynamic Ar, and synthetic air atmospheres. 1 was identified by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) measurements, and quantified by NMR and elemental analysis. Solid intermediates and final decomposition products of 1 prepared in both atmospheres were determined by X-ray diffraction (XRD), Raman spectroscopy, and FTIR. 1 is a complex compound, where Sb is coordinated by three ethyldithiocarbonate ligands via the S atoms. The thermal degradation of 1 in Ar consists of three mass loss steps, and four mass loss steps in synthetic air. The total mass losses are 100% at 800 °C in Ar, and 66.8% at 600 °C in synthetic air, where the final product is Sb2O4. 1 melts at 85 °C, and decomposes at 90–170 °C into mainly Sb2S3, as confirmed by Raman, and an impurity phase consisting mostly of CSO 2 2− ligands. The solid-phase mineralizes fully at ≈240 °C, which permits Sb2S3 to crystallize at around 250 °C in both atmospheres. The gaseous species evolved include CS2, C2H5OH, CO, CO2, COS, H2O, SO2, and minor quantities of C2H5SH, (C2H5)2S, (C2H5)2O, and (S2COCH2CH3)2. The thermal decomposition mechanism of 1 is described with chemical reactions based on EGA-MS and solid intermediate decomposition product analysis.

[5-(Adenin-9-yl)-5-deoxy-L-pentofuranosyl]phosphonates - A Novel Type of Nucleotide Analogs Related to HPMPA. II. Synthesis of L-ribo and L-xylo Configurated Derivatives by Recyclization of Diethyl (5-RS)-[1,2-O-Isopropylidene-5-O-methanesulfonyl-D-pentofuranos-5-C-yl]phosphonates under Acidic Conditions

1993 ◽  
Vol 58 (9) ◽  
pp. 2180-2196 ◽  
Author(s):  
Miroslav Otmar ◽  
Ivan Rosenberg ◽  
Milena Masojídková ◽  
Antonín Holý
Keyword(s):  
Phosphonic Acid ◽  
Trifluoroacetic Acid ◽  
Recyclization Reaction ◽  
Nucleotide Analogs ◽  
Acidic Conditions

Further cyclic analogs of the antiviral (S)-9-(3-hydroxy-2-phosphonomethoxypropyl)adenine (I) were prepared: both anomers of [5-(adenin-9-yl)-5-doxy-L-ribofuranosyl]phosphonic acid (α-IId and β-IId) and [5-(adenin-9-yl)-5-doxy-α-L-ribofuranosyl]phosphonic acid (IIe). Recyclization reaction of diethyl (5RS-(3-O-benzyl-1,2-O-isopropylidene-5-O-methanesulfonyl-D-ribofuranos-5-C-yl)phosphonate (IVb) and diethyl (5RS-(3-O-benzyl-1,2-O-isopropylidene-5-O-methanesulfonyl-D-xylofuranos-5-C-yl)phosphonate (IVd) in trifluoroacetic acid led to cyclic aldehydes Va and Vb which were reduced to diethyl α- and β-L-ribofuranosylphosphonates VIb and α-L-xylofuranosylphosphonate VIIb. Conversion to the protected 5-O-tosylates VId and VIId, followed by reaction with adenine and deprotection, afforded the mentioned nucleotide analogs IId and IIe. An attempt to prepare L-pentofuranosylphosphonates Vc and XIII, suitable for the synthesis of nucleotide analogs of 3-deoxy-L-erythro and L-xylo configuration (IIf and IIg, respectively) by the recyclization reaction of the corresponding 5-O-methanesulfonyl derivatives IVf and XIIb failed. In this case, anhydro derivatives IXa, XVa and XVIa were isolated and identified.

Pyrolysis of ethane in the presence of hydrogen sulfide. Rates of formation of ethylene, hydrogen, and methane

1970 ◽  
Vol 48 (11) ◽  
pp. 1782-1785 ◽  
Author(s):  
P. R. McLean ◽  
D. J. McKenney
Keyword(s):  
Thermal Decomposition ◽  
Hydrogen Sulfide ◽  
Quantitative Data ◽  
Methane Formation ◽  
Partial Product ◽  
Complex Mechanism ◽  
Product Analysis ◽  
Hydrogen Formation

Rates of formation of ethylene, hydrogen, and methane have been measured at 630 °C for the thermal decomposition of ethane at pressures between 100 and 620 Torr, with various pressures (approximately 1 to 100 Torr) of added hydrogen sulfide. The effect of the H2S was to increase the rate of methane formation and to decrease the rate of ethylene and hydrogen formation. Rates of formation of all three of these gases decreased with increasing hydrogen sulfide pressures. The quantitative data obtained and the partial product analysis indicate that a complex mechanism is operative. Possible qualitative explanations for the observations are discussed.

Radicals derived from heteroaromatic systems. II. Thiazolyl radicals

1970 ◽  
Vol 48 (22) ◽  
pp. 3554-3562 ◽  
Author(s):  
Mrs. A. L. Lee ◽  
Donald Mackay ◽  
E. L. Manery
Keyword(s):  
Thermal Decomposition ◽  
Silver Oxide ◽  
Major Product ◽  
Phenyl Ester

2-Thiazolylhydrazine and all three thiazole carbonyl peroxides have been synthesized and examined as radical precursors in solution in benzene, bromobenzene, and cumene. Silver oxide oxidation of the hydrazine or thermal decomposition of the 2-peroxide gives good yields of 2-arylthiazoles but negligible amounts of esters; in cumene a trace of bicumyl is formed. The isomer ratios in bromobenzene and cumene fully support the involvement of 2-thiazolyl radicals (1).The 4-carbonyl peroxide gives fair yields of 4-arylthiazoles but the phenyl ester is also a major product in benzene, indicative of reactions of both 4-thiazolyl radicals (2) and thiazole-4-carbonyloxy radicals. The 5-peroxide gives no products clearly diagnostic of 5-thiazolyl radicals (3) or thiazole-5-carbonyloxy radicals. Bicumyl is a major product of the reactions of the 4- and the 5-peroxides in cumene.

scholarly journals Protection of Aluminum Foils against Environmental Corrosion with Graphene-Based Coatings

2021 ◽  
Vol 8 ◽  
pp. 18-28
Author(s):  
George Paterakis ◽  
George Anagnostopoulos ◽  
Labrini Sygellou ◽  
Costas Galiotis ◽  
◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Sulfuric Acid ◽  
Inhibition Efficiency ◽  
Lithium Perchlorate ◽  
Aluminum Foil ◽  
Corrosion Performance ◽  
Acidic Conditions ◽  
Corrosion Inhibition Efficiency ◽  
Commercial Applications ◽  
Lower Corrosion Rate

Commercial aluminum foils were coated by graphene oxide, and its functionalized derivatives and the corrosion performance of the coated specimens were examined in acidic conditions (lithium perchlorate and sulfuric acid). Electrochemical experiments have shown that all graphene oxide-coated specimens provided up to 96% corrosion inhibition efficiency with a corresponding lower corrosion rate compared to the bare aluminum foil. Our results clearly show that graphene-related materials offer viable alternatives for the protection of aluminum, and this opens up a number of possibilities for its use in a number of commercial applications.

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