Pyrolysis of propane in the presence of propylene

Pyrolysis of propane in the presence of propylene and propylene labeled with C-14 has been studied in the temperature range of 833–1019 K. The strong inhibition effect of propylene on the thermal decomposition of propane has been confirmed.     

Pyrolysis of propane in the presence of acetylene

Pyrolysis of propane in the presence of acetylene and acetylene labeled with C-14 has been studied in the temperature range of 833–1019 K. The inhibition effect of acetylene on the thermal decomposition of propane is turning into an accelerating effect at higher temperature.

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C¹⁴ 833–1019 . .

     

Pyrolysis of propane in the presence of ethylene

Pyrolysis of propane in the presence of ethylene and ethylene labeled with¹⁴C has been studied in the temperature range 773–1019 K. The disappearance of the inhibiting effect of ethylene on the thermal decomposition of propane with increasing temperature was observed.

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¹⁴C 773–1019 . .

     

Pyrolysis of propane in the presence of hydrogen

The pyrolysis of propane in the presence of hydrogen, deuterium and argon was studied in the temperature range 890–1019 K. The acceleration of the reaction in the presence of hydrogen has been observed.

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, 890–1019 . .

     

Photoreaction of mercuric chloride with chloroform in the presence of pyridine

Summary The irradiation of chloroform with ultraviolet light in the presence of pyridine gives dichlorocarbene, which adds to mercuric chloride, giving trichloromethylmercury chloride.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimisheskaya, No. 7, pp. 1285–1286, July, 1965     

Extraction of prussian blue into chloroform in the presence of ajatin

Extraction of Prussian Blue into chloroform in the presence of ajatin (dimethyl-lauryl-benzylammonium bromide) is proposed for the concentration and determination of ferrocyanide ion. Optimum concentrations of sulphuric acid and of ajatin have been established and the selectivity of the extraction has been investigated. Ways of eliminating some interferences are discussed.     

Phosphorylation of polyethylene imines in chloroform in the presence of calix[4]resorcinarenes

Kinetics of the reaction of alkylated polyethylene imines with 4-nitrophenyl bis(chloromethyl)-phosphinate in chloroform in the absence and in the presence of substituted calix[4]resorcinarenes were studied by UV spectrophotometry. It was shown that calixarenes forming mixed aggregates with polyethylene imines have a catalytic effect on the polymer phosphorylation process. The catalytic effect depends on the structure of polyethylene imine and the component ratio in the system.     

Cyanoethylation of trichlorosilane

Summary It was shown that 3-(trichlorosilyl)propionitrile can be synthesized by the addition of trichlorosilane to crylonitirile in presence of Raney nickel.     

Some reactions of grignard reagents with chloroform and carbon tetrachloride in the presence of cyclohexene

The reactions of phenylmagnesium bromide and ethylmagnesium iodide with carbon tetrachloride in the presence of cyclohexane are reported. The identified products include 3,3′- bicyclohexenyl, dichloromethylcyclohexane, 7,7-dichloronorcarane, 7,7-dibromonorcarane and 7-bromo-7-chloronorcarane. The phenyl Grignard reagent reacts primarily by an ionic pathway, whilst a radical mechanism also occurs with the ethyl Grignard reagent.     

Reaction of 2,4-di-t-butyl-6-methylphenylphosphonous dichloride with chloroform in the presence of lithium diisopropylamide

2,4-Di-t-butyl-6-methylphenylphosphonous dichloride reacted with chloroform in the presence of lithium diisopropylamide to give (2,4-di-t-butyl-6-methylphenyl) (dichloromethyl) (1,2,2-trichloroethenyl)phosphine. The structure of this phosphine was analyzed by X-ray crystallography. This phosphine further reacted with butyllithium to give (1-butylpentylidene)(2,4-di-t-butyl-6-methylphenyl)phosphine bearing a low-coordinated phosphorus atom. © 1996 John Wiley & Sons, Inc.     

Preparation of polypyrrole-coated platinum modified electrode in chloroform in the presence of various supporting electrolytes and its use for the catalytic oxidation of hydroquinone in aqueous and chloroform solutions

Polypyrrole (PPy)-coated platinum modified electrode was prepared electrochemically in chloroform in the presence of tetrabutylammonium perchlorate, tosylate, tetrafluoroborate, periodate, and hydrogen sulphate. Evidence in favour of the occurrence of a redox reaction at the film/solution interface was given by ferrocene oxidation. The electrocatalytic effect of the PPy-coated electrode was revealed by oxidation of hydroquinone on it in water and chloroform. The influence of dopant anion, method of electrosynthesis and operation temperature were demonstrated. The calculated heterogeneous electron transfer rate constant (k(o)) at the PPy-modified Pt electrode at 25 degrees C was 1.4 x 10(-3) cm/sec which is 1000-fold greater than the value (< 10(-6) cm/sec) reported for bare electrode.     

Thermal reaction of β-carotene: Part 2. Pyrolysis in the presence of kaolinite

β-Carotene was heated with a clay mineral (kaolinite) under vacuum at temperatures ranging from 200 to 350°C for 24 h. Several polymethylbenzenes, naphthalenes and probably phenanthrenes were observed in the pyrolysate at 350°C. Furthermore, ionene, some polymethylbenzenes and a dimethylnaphthalene were detected at temperatures between 200 and 250°C. It was concluded that the clay mineral may act as an acidic catalyst.     

Lewis base mediated dismutation of trichlorosilane

An abnormal N-heterocyclic carbene (aNHC) has been used as a Lewis base to initiate dismutation of trichlorosilane. This report presents the reactivity differences of a normal N-heterocyclic carbene (NHC) versus aNHC with heavier group 14 elements. Three novel compounds (NHC)(2)·SiCl(2)H(2) (2), aNHC·SiCl(2)H(2) (3), and aNHC·GeCl(2) (4) have been synthesized and characterized by single crystal X-ray analysis, solid-state NMR and DFT calculations.     

Experimental and theoretical study of the pyrolysis of trichlorosilane

Pyrolysis of trichlorosilane (TCS) and copyrolysis of TCS with 1,3-butadiene were studied. The enthalpies and activation energies for the reactions of the products of TCS pyrolysis were found by quantum-chemical calculations. A direct study of the pyrolysis of TCS by mass spectrometry was carried out. Based on the thermochemical parameters found by quantum-chemical calculations and on the results of GLC and mass spectrometry concerning the composition of the pyrolysis products, it was concluded that the pyrolysis of TCS follows a scheme that includes formation of radicals and silylenes. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1659–1662, September, 1997.     

Hydrosilylation of diallyl sulfide with trichlorosilane

Conclusions By the hydrosilylation of diallyl sulfide with trichlorosilane, catalyzed by the Nt(acac)₂-tert-phosphine systems, mono- and bis-trichlorosilyl derivatives were obtained. Conditions were found for the preferential preparation of each of these compounds. Besides mono- and bis-adducts, 1-trichlorosilyl-4-thioheptane is also formed.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2119–2121, September, 1981.     

Pyrolysis of hexamethylcyclotrisilthiane and tetramethylcyclodisilthiane in the presence of cyclic siloxanes: evidence for the intermediacy of dimethylsilathione

Copyrolysis of hexamethylcyclotrisilthiane and hexamethylcyclotrisiloxane yields 1,1,3,3,5,5,7,7-octamethyl-2,4,6-trioxo-1,3,5,7-tetrasila-8-thiacyclooctane. Likewise, copyrolysis of hexamethylcyclotrisilthiane or tetramethylcyclodisilthiane with 1,1,3,3-tetramethyl-2-oxa-1,3-disilacyclopentane yields 1,1,3,3,5,5-hexamethyl-2-oxa-1,3,5-trisila-4-thiacycloheptane. Possible mechanisms are discussed.     

Pyrolysis of 1,1,1-Trichloroethane in the absence and the presence of added HCl and/or CCl4

The title reaction has been studied in a static quartz reaction vessel between 587 and 658 K at pressures between 40 and 152 torr. The dehydrochlorination is the only significant reaction and is autoaccelerated by the produced HCl. Numerical modelling indicates that the Rice-Herzfeld mechanism, generally used for describing the pyrolysis of halogenated ethanes, has to be completed in the case of CC1₃CH₃ with additional transfer reactions converting “dead” radicals into chain carriers and vice-versa. The numerical simulation fits the experimental results, in the absence as well as in the presence of different amounts of added HCl. The dehydrochlorination is also accelerated by the addition of CCl₄, which can be explained in terms of additional elementary steps involving · CCl₃ radicals.     

Pyrolysis of propane in the presence of14C2H4 studied by the kinetic isotope method

The kinetic isotope method was used to explain the role of ethylene in the pyrolysis of propane. The mechanism of the radioactivity appearance in methane and propylene is proposed.     

Telomerization of ethylene and carbon tetrachloride or chloroform in the presence of the hexacarbonyls of chromium,molybdenum, and tungsten

summary The reaction of telomerization of ethylene with carbon tetrachloride or chloroform is initiated by hexacarbonyls of chromium, molybdenum, and tungsten at 115–120, forming ,,,-tetrachloroalkanes and ,,-trichloroalkanes. respectively.