The Transformation of Thiols Compounded in Raw Rubber

1951 ◽  
Vol 24 (4) ◽  
pp. 914-915
Author(s):  
Jeanle Bras ◽  
Michel Montu
Keyword(s):  
Absorption Spectra ◽  
Analytical Method ◽  
Ultra Violet ◽  
Transformation Products ◽  
Ultraviolet Absorption ◽  
The Other ◽  
Inert Gas ◽  
Rubber Industry ◽  
Acetone Extraction ◽  
The One

Abstract During the last few years the rubber industry has made use of certain thiols, under the technical name of peptizing agents, which have the property of accelerating the plasticization of raw rubber during mastication. It is now known that this process of plasticization involves oxidation of the rubber, and that it does not take place in an atmosphere of an inert gas. Accordingly the present authors were induced, on the one hand, to follow the transformation of thiols during their participation in the mastication of rubber and, on the other hand, to observe their influence on the tendency of rubber to oxidize. In the first of these objectives, the analytical method utilized was ultra- violet absorption spectrography. To avoid pertubations in the spectra caused by the resins present in rubber, crepe rubber purified by acetone extraction was used in the experiments. The rubber was masticated at 100° C, and the thiol was added soon after the beginning of this mastication in the proportion of 5 per cent of the rubber. Samples were withdrawn at successive intervals of time, and the transformation products of the thiol, which were isolated by acetone extraction, were identified by their ultraviolet absorption spectra. In these experiments, chloroform solutions containing 0.5 gram per liter were employed.

II. On the spectrum of the oxyhydrogen flame

1888 ◽  
Vol 43 (258-265) ◽  
pp. 347-348
Keyword(s):  
Visible Region ◽  
Ultra Violet ◽  
The Other ◽  
The One ◽  
Oxyhydrogen Flame

In a former communication the authors described simultaneously with Dr. Huggins the strongest portion of the spectrum of water, subsequently they described a second less strong but more refrangible section of the same spectrum. M. Deslandres has noticed a third still more refrangible section. The authors now find that the spectrum extends, with diminishing intensity, into the visible region on the one hand, and far into the ultra-violet on the other.

Colour: Physical or Phenomenal?

Philosophy ◽  
1998 ◽  
Vol 73 (2) ◽  
pp. 301-304
Author(s):  
RUSSELL WAHL ◽  
JONATHAN WESTPHAL
Keyword(s):  
Absorption Spectrum ◽  
Absorption Spectra ◽  
The Other ◽  
Psychological State ◽  
Necessary Truths ◽  
The One ◽  
Colour Terms

We wish to defend Jonathan Westphal's view that colour is complex against a recent ‘phenomenological’ criticism of Eric Rubenstein. There is often thought to be a conflict between two kinds of determinants of colour, physical and phenomenal. On the one hand there are the complex physical facts about colour, such as the determination of a surface colour by an absorption spectrum. There is also, however, the fact that the apparently simple phenomenological quality of what is seen is a function of the physiological and psychological state of the viewing subject. Should the physical trump the phenomenal, or is it the other way round?Much of the phenomenal variation of colour, however, is explained by physical facts. There is a physics and a psychophysics of colour. Colours appear, to the colour scientists at least, to be in some sense objective, a sense not explained by the view that they are purely phenomenal. Taking physics and psychophysics into account will mean rejecting the claim that the content of what our concepts of colours are concepts of is exhausted by the purely phenomenal, or that we can determine these concepts simply by gazing at a colour. Taking account of physics will lead, as Westphal argued, instead to a view about white and the other colour terms like Putnam's account of gold. Necessary truths about colours cannot be explained without reference to the logic of the compossibility of what is given in reflection and absorption spectra, the analogue of H2O.

TRYPTAMINES, CARBOLINES, AND RELATED COMPOUNDS: PART IX. THE CYCLIZATION OF SOME NITRO- AND AZIDO-PHENYLPYRIDINES. PYRIDO[1,2-b]INDAZOLE

1961 ◽  
Vol 39 (12) ◽  
pp. 2516-2528 ◽  
Author(s):  
R. A. Abramovitch ◽  
K. A. H. Adams
Keyword(s):  
Absorption Spectra ◽  
Catalytic Reduction ◽  
Nitro Compounds ◽  
Ultraviolet Absorption ◽  
The Other ◽  
Azo Compounds ◽  
Minute Amount ◽  
Ferrous Oxalate ◽  
Related Compounds ◽  
General Method

Heating 2-o-nitrophenylpyridine with ferrous oxalate gives rise to pyrido[1,2-b]indazole (III). The evidence for the structure of this compound is discussed. Similarly, heating 2-o-nitrophenylpyridine methiodide and N-oxide with ferrous oxalate gives (III), in each case, demethylation and deoxygenation preceding the cyclization. In the latter case a minute amount of δ-carboline is also formed. Heating pyridine-N-oxides with ferrous oxalate is a potentially general method of effecting deoxygenations of these compounds. Contrary to the results of Smith and Boyer (11), it is found that heating 2-o-azidophenylpyridine also gives rise to (III). On the other hand, the action of heat on 2-o-azidophenyIpyridine-N-oxide gives a mixture of δ-carboline and δ-carboline-py-N-oxide in low yield. The mechanism of the cyclization of the azides and of the reaction taking place on heating nitro-compounds with ferrous oxalate is discussed briefly; the formation of a nitrene intermediate is favored.The catalytic reduction of 2-o-nitrophenylpyridine-N-oxide giving rise to the azoxy-, azo-, and hydrazo-derivatives is described and the ultraviolet absorption spectra of these compounds are discussed. It is concluded the steric inhibition of coplanarity exists in the azoxy- and azo-compounds leading to the lack of effective conjugation across the N=N bond.

scholarly journals INFLUENCE OF LIGHT ON THE GROWTH AND MALIGNANCY OF A TRANSPLANTABLE NEOPLASM OF THE RABBIT

1927 ◽  
Vol 45 (3) ◽  
pp. 483-496 ◽  
Author(s):  
Louise Pearce ◽  
C. M. Van Allen
Keyword(s):  
Experimental Evidence ◽  
Malignant Disease ◽  
External Factor ◽  
Continuous Light ◽  
Ultra Violet ◽  
The Other ◽  
Constant Light ◽  
Constant Darkness ◽  
Light Conditions ◽  
The One

An experiment is reported in which an environment of constant and continuous light excluding the shorter ultra-violet rays, and one of constant darkness, have influenced the course and character of a malignant disease of rabbits induced by a transplantable neoplasm. Under the influence of constant light the level of malignancy was observed to be low; under the influence of constant darkness the level of malignancy was somewhat lower than in the control animals living under ordinary indoor light conditions, but the level was not as low as among the animals constantly illuminated. These observations furnish experimental evidence in support of the idea that there is a correlation between the external factor of light on the one hand and the manifestations of an experimental malignant disease on the other.

Complexes moléculaires d'hétérocycles soufrés et oxygénés. Étude spectrophotométrique de bandes de transfert de charge multiples

1982 ◽  
Vol 60 (7) ◽  
pp. 862-871 ◽  
Author(s):  
Jean-Paul Canselier ◽  
Serge Domenech ◽  
Štefan Stankovsky ◽  
Sabine Gautier
Keyword(s):  
Charge Transfer ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Molecular Complexes ◽  
The Other ◽  
Ionization Potentials ◽  
Nonpolar Solvents ◽  
Other Hand ◽  
The One

As with benzenoid donors, the electronic absorption spectra of the molecular complexes of simple or condensed sulfur or oxygen-containing five-membered heterocycles with TCNE (or DDQ) often show two charge-transfer bands. In many cases, the knowledge of the actual frequencies requires a technique of resolution. The results so obtained are correlated with the ionization potentials of donors on the one hand, and the refractivity of nonpolar solvents on the other hand.

SOME OBSERVATIONS ON THE THEORY OF π-BONDING IN INORGANIC COMPOUNDS

1960 ◽  
Vol 38 (8) ◽  
pp. 1300-1304 ◽  
Author(s):  
A. D. Westland
Keyword(s):  
Inorganic Compounds ◽  
Lattice Energy ◽  
The Other ◽  
Inert Gas ◽  
Quantitative Relation ◽  
Iron Group ◽  
Multiple Bonding ◽  
Lattice Energies ◽  
The One ◽  
Electron Donation

Evidence for the existence of multiple bonding due to d-electron donation by non-inert gas type ions is discussed briefly. A quantitative relation between the heats of formation of binary halides and chalcides containing non-inert gas type cations, on the one hand, and inert gas type cations, on the other, reveals an enhanced lattice energy in the former class of compounds. It is shown that this may be accounted for in the case of iron group elements without recourse to the postulate of participation of d-electrons in the bonding, as satisfactory estimates of the lattice energies of halides and sulphides may be made on the basis of values for group IIa compounds.

Studies of phase transformations in nitrates and nitrites I. Changes in ultra-violet absorption spectra on melting

1963 ◽  
Vol 276 (1367) ◽  
pp. 437-452 ◽  
Keyword(s):  
Nitric Acid ◽  
Phase Transformations ◽  
Ammonium Nitrate ◽  
Absorption Spectra ◽  
Ultra Violet ◽  
The Other ◽  
Sodium Potassium ◽  
Nearest Neighbours ◽  
Isopropyl Nitrate ◽  
Sodium And Potassium

Ultra-violet absorption spectra of ions in crystals are sensitive to their environment of neighbouring ions. This fact is utilized to study melting processes in nitrates and nitrites, with particular reference to changes in the average shell of nearest neighbours around any ion, on passing from crystal to melt. For the nitrates of sodium, potassium, rubidium, caesium, thallium and silver, for ammonium nitrate and for the nitrites of sodium and potassium this shell appears to contract on melting, which is attributed to the formation of association complexes in the melt. For the two crystal hydrates HNO 3 . H 2 O and HNO 3 . 3H 2 O, corresponding changes are observed, suggesting that the structure and absorption spectra correspond with the ions (OH 3 )+ and NO - 3 in the crystals, likewise giving rise to tighter association complexes on melting. Pure nitric acid on the other hand behaves in a manner more closely similar to isopropyl nitrate.

scholarly journals The absorption spectra of benzene derivatives in the vacuum ultra-violet. II

1947 ◽  
Vol 191 (1024) ◽  
pp. 32-38 ◽  
Keyword(s):  
Absorption Spectra ◽  
Ultra Violet ◽  
Phenyl Isocyanate ◽  
The Other ◽  
Side Chain ◽  
Benzene Derivatives ◽  
Phenyl Acetylene ◽  
Long Wave ◽  
Methyl Styrene ◽  
Vacuum Ultra Violet

The far ultra-violet spectra of styrene, α -methyl styrene, phenyl acetylene, phenyl cyanide and phenyl isocyanate are described. Many of the observed regions of absorption are cor­related with those of the benzene spectrum. The important fact emerges that, with increasing conjugation of the side chain with the ring, the benzene 1980 A absorption moves much farther to long wave-lengths than do the benzene 2600 and 1790 A absorptions. α -Methyl styrene shows a shift to the violet of certain regions of its spectrum relative to styrene. Phenyl isocyanate has a spectrum much closer to that of benzene than have the other molecules discussed.

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