Cyano Radical Research Articles

Perturbation analysis and constants for the red system of the cyanide radical

A χ 2 test has been used to obtain improved molecular constants for the A 2Φ- X 2Σ system of the C 12N 14 radical. The new constants predict wavenumbers that agree with the observed valued to 0.1 Å for rotational levels up to N” = 80 for the lower vibrational bands and up to N“ = 50 for the higher bands. Wavenumbers for the (2,0) and (3,1) vibration-bands of the C 13N 14 radical have also been computed with these molecular constants. They agree to 0.1 Å with the measurements of Wyller (11) if the electronic isotope shift between the electronic states of the C 12N 14 radical is 0.2 cm -1. In the present calculations, the effect of degenerate perturbations between the 2Φ and 2Σ states is included.

The reaction of active nitrogen with acetylene. I

The reaction between active nitrogen and acetylene was studied in a low-pressure flow reactor using a leak to a mass spectrometer as the analytical device and varying reaction time from a few to 45 ms. In mixtures in which the initial ratio of acetylene to atomic nitrogen is larger than unity a comparatively slow reaction takes place whose main products are cyanogen, hydrogen and cyanoacetylene. The reaction is accelerated by rising pressure and temperature. The proposed rate determining steps are C 2 H 2 + N K1 ⇆ K-1 C 2 H 2 N*, C 2 H 2 N*+ N 2 → K2 C 2 H 2 N+ N 2 with K 1 = 1·1X 10 -12(+-0·12) exp (-2000(±400)/ RT ) cm 3 molecule -1 s -1 and k -1 = 4x10 -s T e s -1 , if k 2 is taken to be the collisional frequency. The radical C 2 H 2 N is found to react competitively with nitrogen atoms and with acetylene to form the end products. At low (≤ 0·5) initial acetylene to atomio nitrogen ratios a much faster reaction occurs which is accompanied by chemiluminescence of CH and CN radicals and whose main products are hydrogen cyanide, cyanogen and hydrogen. Simultaneously, a rapid recombination of nitrogen atoms takes place, as many as 20 atoms reacting per molecule of acetylene consumed. This rapid reaction has a negative temperature coefficient. It is suggested that this is a chain reaction started by metastable nitrogen molecules ( A 3 Σ + u ) nitrogen atoms which react with acetylene to form hydrogen cyanide and cyanide radicals. The latter cause the recombination of nitrogen atoms by the chain reactions CN + N + N 2 → NCN + N 2 NCN+N → N* 2 + CN, with 3 x 10-30 <k 6 < 2 x 10 -29 cm 6 molecule -2 s -1 . These chains are broken by recombination of cyanide radicals and by the reactions of CN and NCN radicals with acetylene. Cyanogen also causes a catalytic recombination of nitrogen atoms. Ammonia added to acetylene-active nitrogen mixtures suppresses the rapid reaction but has no effect on the slow reaction in richer mixtures.

The Reaction between Hydrocarbon and Hydrogen Cyanide in Silent Electrical Discharge. III. The Reaction of Ethylene or Propylene with Hydrogen Cyanide

Abstract The present investigation was undertaken to find out whether or not the relative amounts of acrylonitrile obtained by the reaction between ethylene and hydrogen cyanide in a silent discharge are affected by the substances (Hg(CN)2, Cu, CuCN, Al, Zn and Fe) placed in a glass filter of the special discharge tube, and to examine the possibility of the direct introduction of a cyano radical into propylene by means of the silent discharge. The yield of acrylonitrile depended upon the packing materials in the glass filter. When the discharge wall of the glass filter was filled with Hg(CN)2, the yield of acrylonitrile was at its maximum. When a mixture of propylene and hydrogen cyanide was discharged in an ozonizer in the absence of air, the main liquid products were crotononitrile, methacrylonitrile, and n-propyl cyanide. Besides these compounds, the reaction products were confirmed to consist of isopropyl cyanide, acetonitrile, acrylonitrile, 4-methyl-1-pentene, 2,3-dimethylbutane, 1,5-hexadiene, 2-methylpentane, 1-hexene, n-hexane, and gaseous products. Judging from the relative concentration of each compound in the reaction products, it may be said that 2-methylvinyl, isopropenyl, propyl, allyl, isopropyl, and cyano radicals are the main intermediates in this reaction system.

The Reaction between Hydrocarbon and Hydrogen Cyanide in Silent Electrical Discharge. II. The Formation of Acrylonitrile from Ethylene and Hydrogen Cyanide

Abstract The present investigation was undertaken to examine the possibility of the direct introduction of a cyano radical into ethylene by means of a silent discharge. When a mixture of ethylene and hydrogen cyanide was discharged in an ozonizer under atmospheric pressure, the main liquid product was acrylonitrile, though the formation of telomers, such as ethyl cyanide, n-butyl cyanide and n-hexyl cyanide, was also observed. Besides these compounds, the reaction products were confirmed to consist of s-butyl, n-propyl, isopropyl, n-amyl, and isoamyl cyanides, and a gaseous product. The yield of acrylonitrile was affected by the temperature and voltage of the discharge. It has been found that the yields of the liquid products and the gaseous product increase with the rise in the temperature and voltage of the discharge, while the relative ratio of acrylonitrile to the other liquid product decreases. Judging from the relative concentration of each compound in the reaction products, it may be said that the vinyl radical and the cyano radical are the main intermediates in this reaction system.

The Reaction between Hydrocarbon and Hydrogen Cyanide in Silent Electrical Discharge. I. The Formation of Cyclohexyl Cyanide from Cyclohexane and Hydrogen Cyanide

Abstract In order to examine the possibility of the direct introduction of a cyano radical into cyclohexane by means of silent discharge, a mixture of cyclohexane and hydrogen cyanide was discharged in an ozonizer under various conditions. As a result, cyclohexyl cyanide was obtained. The yield of cyclohexyl cyanide depended upon the voltage of discharge, the residence time in the discharge tube, the temperature of the discharge tube, and the structual characteristics of the apparatus. In the refluxing method the maximum yield of cyclohexyl cyanide was obtained when the discharge was carried out at a low temperature. Besides cyclohexyl cyanide, the reaction products were confirmed to consist of bicyclohexyl, cyclohexene, methylcyclohexane, ethylcyclohexane, 3-cyclohexylcyclohexene, methylenecyclohexane, 1-hexene, n-hexane, n-pentane, methylcyclopentane, a solid brown deposit, and cracked gas. The principal reactions can be interpreted as being the formation of cyclohexyl and cyano radicals and the combination of these radicals, their dehydrogenation, their isomerization, their polymerization, and their decomposition.

Serum thiocyanate concentrations in tobacco amblyopia.

THERE has recently been interest in the suggestion that tobacco amblyopia may be a manifestation of chronic cyanide toxicity, the cyanide radical being derived from tobacco smoke1–3. Although it is known that cyanide in the body is chiefly detoxified to thiocyanate and that smokers show higher serum thiocyanate concentrations than non-smokers4, no study of serum thiocyanate concentrations in those affected by tobacco amblyopia has been reported.

Aspects of mass spectra of organic compounds. Part V. Some phenazines

The mass spectra of phenazine and a number of substituted phenazines have been examined. The substituted phenazines generally fragment by initial loss of substituents, and different effects were observed depending on the relative positions of the substituents in the same or different rings. Phenazine itself loses the central nitrogen atoms first as cyanide radicals or as hydrogen cyanide, but substituted phenazines only suffered similar losses after elimination of the substituents.

The Direct Introduction of Cyano and Ethoxycarbonyl Radicals into Cyclohexane by a Photochemical Reaction

The Direct Introduction of Cyano and Ethoxycarbonyl Radicals into Cyclohexane by a Photochemical Reaction

Determination of electron affinities. Part 5.—Cyanide and thiocyanate radicals

Determination of electron affinities. Part 5.—Cyanide and thiocyanate radicals

THE REACTIONS OF ACTIVE NITROGEN WITH CYANOGEN AND CN RADICALS

Cyanogen is destroyed by active nitrogen at temperatures of 80° to 400 °C, and nitrogen pressures of 0.34 to 3.1 mm, with the formation of polymer. At 400 °C and sufficiently high flow rates of cyanogen, a constant amount is destroyed, which apparently corresponds to practically complete consumption of the available nitrogen atoms.The formation of CN radicals in the reaction of cyanogen with active nitrogen was established by the production of HCN and CH3CN when hydrogen or methane was added to the reaction mixture. The rate of destruction of cyanide radicals, when they were transported through a reaction vessel, was determined by introducing hydrogen below the site of reaction, and found to follow first order kinetics.

MASS SPECTROMETRIC STUDY OF THE REACTIONS OF SOME HYDROCARBONS WITH ACTIVE NITROGEN

The reactions of active nitrogen with acetylene, ethylene, and propylene have been studied in a flow system using a mass spectrometer to analyze the products continuously. Certain features of the mass spectra of the products can be explained on the basis of cyano radical replacement reactions.

Distribution of C14-labeled aminoacetonitrile in tissues of rat, metabolism and mode of elimination.

SummaryAminoacetonitrile, with C14 in its cyanide group, was synthesized. When this compound was administered to weanling rats, the major portion of the radioactivity was eliminated in the urine, while a minor part appeared in respiratory CO2. High initial C14 concentrations were observed in various body tissues. The proportion of this C14 due to unchanged nitrile decreased fairly rapidly with time. Labeling was found in tissue proteins, and to a lesser extent in liver lipids and glycogen. Also, in rats fed a diet containing isotopic aminoacetonitrile, radioactivity was detected in the sulfated polysaccharides of the enlarged epiphyseal plates of the bones. The presence of C14 in glycine and serine of liver protein and in urinary creatinine, allantoin, and hippuric acid, indicated an appreciable conversion of the cyanide radical into a carboxyl group. However, the major portion of the C14-containing metabolites was not identified.

Reactions of haems with cyanides, isocyanides and amino acids.

HAE (ferrous protoporphyrin) combines with nitrogenous bases to form haemochromogens showing, in the visible region of the spectrum, two sharp absorption bands, α 557 mµ and β 525 mµ, of which the α-band is much the stronger. It has been shown that in haemochromogens two molecules of base are linked with each iron atom of haem1. Potassium cyanide, however, differs from haemochromogen-forming substances in giving with haem two compounds containing one and two cyanide radicals per molecule of haem2,3. Whereas the absorption spectrum of monocyan-haem resembles that of the haemochromogens, the absorption spectrum of dicyan-haem differs from it, the bands being displaced towards the red end of the spectrum, and the β-band being stronger than the α-band.

TIME REQUIRED FOR BLOOD TO FLOW FROM THE ARM AND FROM THE FOOT OF MAN TO THE CAROTID SINUSES

No attempt has been made to review the literature on circulation time completely for this presentation. Extensive references may be found elsewhere.1All methods depend on determination of the time elapsing between intravascular injection of a substance and its arrival at another part of the body. This arrival may be determined objectively2or subjectively.3Loevenhart and his associates4noted marked respiratory stimulation in animals and man following intravenous injection of a solution of sodium cyanide and proposed the use of sodium cyanide for the determination of circulation time in man. Robb and Weiss, however, carried out the first clinical study. Since then there have been several reports.5 The principal site of action of the cyanide radical has been demonstrated by Heymans and his associates6to be the carotid bodies. Winder and his associates7confirmed this effect on the carotid reflex mechanism by direct

The Thermal Dissociation of Cyanogen into Cyanide Radicals. A Correction

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The Thermal Dissociation of Cyanogen into Cyanide Radicals

The thermal dissociation of cyanogen into cyanide radicals around 1200°C has been studied. Determining the variation of CN concentration with temperature by the intensity of absorption bands, the heat of dissociation 77±4 kg cal. has been obtained. With this quantity the heat of dissociation of hydrogen cyanide into hydrogen atoms and cyanide radicals is calculated as 94.5±4 kg cal. By the use of existing thermochemical data these quantities are shown to be the most probable values for the energies of the C–C and C–H bonds, respectively. The heat of sublimation of carbon is calculated as 154±3 kg cal.