bluuebunny/crossref_metadata_2025 huggingface dataset:
The dimensions of charged long chain molecules in solutions containing electrolytes
Authors: Hermans J. J. , Overbeek J. TH. G.
Published: September 2010

If a long chain molecule in a solution carries electric charges, the statistical coil is inflated, and the average square of the distance between the ends of the chain is larger than in the uncharged state. For a number of properties the determining factor is the value of ∑k (r2k)av, where rk is the distance between the k'th link in the molecule and the centre of gravity. This quantity is proportional to the square of the effective radius and is related to the square of the distance between the ends by a simple formula (section 2), provided the radius of the coil is small compared with the length of the extended chain.

In section 3 the electrical free energy of the molecule is derived as a function of effective radius on the assumption that no electrolytes are present. This free energy determines in its turn the average dimensions of the coil.

In section 4 a similar theory is developed for charged polymer molecules in the presence of electrolytes. The change of the effective radius with the charge on the polymer and the concentration of the electrolytes is calculated. In the limit of high electrolyte content the equilibrium between the interior and the exterior of the polymer coil may be considered as a Donnan equilibrium.
Spectrophotometrical determination of carbon monoxide in blood
Authors: Pieters H. A. J. , Hanssen W. J.
Published: September 2010

In order to determine whether a light case of poisoning is due to carbon monoxide, we must be able to demonstrate its presence and to determine its concentration in the patient's blood. In the method developed by Sayers and Yant

R. R. Sayers and W. P. Yant, Technical Paper 373 D.O.C. Bureau of Mines (1925).

tannin is added to the blood sample, by which a red precipitate is formed. The colour of the sample is compared with a series of blood‐samples containing known quantities of carbon monoxide. This method takes a long time, a sample of carbon monoxide‐free blood must be available and the accuracy is about 5% CO at the utmost. As the absorption spectra of CO‐haemoglobin (CO‐Hb), oxyhaemoglobin (O2‐Hb) and haemoglobin (Hb) are different, it is possible in principle to determine the CO in blood spectrophotometrically

K. Hinsberg, Z. Anal. Chem. 121, 435 (1941).

.

We have examined the following factors:

The wave lengths at which the absorption by the components Hb, O2Hb, COHb is maximal and minimal.

The reproducibility of the results obtained with blood‐samples of different origin saturated with a) CO and b) O2.

The stability of COHb in blood

haemolysed with sodium carbonate

haemolysed with saponin

treated with air.

We have determined the extinctions at two wave‐lengths and derived the CO‐concentration from the quotient of the extinctions.

A procedure is described.
Nouveaux α, β, β‐triaryléthènes substitués
Authors: Buu‐Hoï Ng. Ph. , Hoán N. G. , Lecocq J. , de Clercq M.
Published: September 2010

Dans ce travail, on décrit plusieurs nouveaux α,β,β‐triaryléthènes substitués qui ont été synthétisés dans le but d'examiner certaines de leurs propriétés physiologiques telles que le pouvoir oestrogène. La condensation avec le cyanure de benzyle sodé de diverses diarylcétones conduit à une série d'α,β,β‐triarylacrylonitriles appartenant à des familles variées (benzène, naphthalène, acénaphthène, diphényle, etc……). Dans certain cas, les 2 stéréoisomères prévus par la théorie ont pu être effectivement isolés; en outre, il a été observé que les cétones dirivées du noyau thiophène telles que le 2‐benzoylthiophène ou le 3‐benzoyl‐2,5‐thioxène ne se condensent pas avec le cyanure de benzyle sodé à l'amidure. Enfin, des α,β,β‐triaryléthènes et α‐bromo‐α,β,β‐triaryléthènes à noyau naphtalène, acénaphtène, diphényle, et pyrrole, ont été également synthétisés par les méthodes habituelles en vue de leur étude physiologique.
Relations between refraction, density and structure of series of homologous hydrocarbons. I. Empirical formulae for refraction and density at 20°C of n. alkanes and n. alpha‐alkenes
Authors: Smittenberg J. , Mulder D.
Published: September 2010

In studying the relations between physical constants of pure hydrocarbons, it was found that in many cases it is possible to express the constants of hydrocarbons belonging to a homologous series by an empirical formula of the type: x = x∞ + k/(c + z), where x represents the physical constant of a hydrocarbon, containing c carbon atoms, x∞ the limit of this physical constant at an infinite number of carbon atoms, and k and z empirical constants, characteristic for the series.

Relations of this type are very valuable for control of purity of available hydrocarbon‐samples, for predicting the constants of unknown members of the series and for the analysis of hydrocarbon‐mixtures, particularly in the regions of higher molecular weight, where direct measurements of physical constants of individual hydrocarbons are scarce.

This first publication of a series gives formulae of the above‐mentioned type for refraction and density at 20° C of n‐alkanes and n‐alpha‐alkenes, and linear relations between these two constants for both series.
Researches on plant growth regulators XIV. The influence of synthetic plant growth substances on lipoid monolayers
Authors: Havinga E. , Veldstra H.
Published: September 2010

In connection with the hypothesis that plant growth substances do not exert their growth promoting activity by a chemical reaction proper (e.g. functioning as redox‐catalysts) but by a more physical type of action on certain structures in the living cell, experiments were made on the influence of these compounds on monolayers of lecithin or oleic acid spread on aqueous solutions.

It was found that apparently plant growth substances penetrate into and accumulate in such monolayers, their influence generally consisting in seemingly increasing the molecular area in the film. In some cases (decahydro‐naphthylacetic acid or undecanoic acid in the hypophases) very peculiar curves were obtained.

The activity of a number of compounds tested in this way may be understood by considering the balance between the lipophilic part of the molecules and the hydrophilic carboxyl group.

Although the type of action proved to be qualitatively as expected, a parallelism between the growth promoting activity of the compounds and their influence on these simple surface layers does not exist.

Further detailed studies must provide an answer to the question whether the difference between the action in the model systems and in vivo might be caused by the apparently much too simple and aspecific composition of the films used, or whether, with the ideas put forward in

H. Veldstra, Enzymologia 11, 97, 137 (1944).

, the physiological action has been simplified too much.
Preparation and some properties of diethylsilazines
Authors: de Man W. , van Steenis J. , Waterman H. I.
Published: September 2010

Diethyldichlorosilane reacts with dry ammonia to give hexaethylcyclotrisilazine. Intermediates in this reaction are linear ethylsilazines which may contain chlorine atoms.

The silazines decompose under the influence of moisture into NH3, diethylsilanediol and silicones.

The preparation of diethyldichlorosilane from silicon tetrachloride and ethylmagnesium bromide has been improved.
Nitration of 3,5‐diethoxypyridine
Authors: den Hertog H. J. , van Weeren J. W.
Published: September 2010

Königs, Gerdes and Sirot have prepared a 3,5‐diethoxy‐dinitropyridine by nitrating 3,5‐diethoxypyridine. On repeating this experiment we have obtained a mono‐nitro‐derivative. We have proved that in this compound the nitro group is introduced into the 2‐position.

When the 3,5‐diethoxy‐2‐nitropyridine is nitrated further the dinitrocompound described by Königs et al. is obtained. The nitro groups in this compound are in the 2‐ and 6‐positions.
The swelling of cellulose xanthate gels in dilute salt solutions
Authors: Vermaas D. , Hermans J. J.
Published: September 2010

A theory is developed which connects the degree of swelling of a polymer network bearing ionogenic groups with the electrolyte concentration in the swelling medium.

It is based on the assumption of an electrolyte distribution according to a Donnan equilibrium between the gel and the surrounding liquid on the one hand, and on the application of a modified Flory‐Rehner equation to the dependence of the free energy of dilution on the degree of swelling on the other hand.

This theory is applied to the swelling of cellulose xanthate gels in neutral salt solutions. The following conclusions are reached.

The theoretical relation between the degree of swelling q and the electrolyte concentration c has the form q5/3 = B/βλc + (1‐K)/2 β, where B, β and K are constants related to fundamental physical properties of the swollen network; λ is a valency factor of the electrolyte studied.

In agreement with this formula the experimental q5/3‐ 1/λc plots are linear at moderate degrees of swelling and fairly independent of the electrolyte used. An explanation is given for deviations from linearity observed in highly swollen systems.

From the slope of the experimental swelling curves it is concluded that the network consists of short chains.

Apart from the influence of the valency of the ions there exists also a lyotropic influence of the ions on the swelling of the gel.

The strong dependence of swelling on the xanthate ratio of the gel is in quantitative agreement with the effect predicted by theory.
The determination of acetic acid and propionic acid in bacteriological culture media
Authors: Tasman A. , Smith L.
Published: September 2010

The problem of determining small quantities of acetic acid and propionic acid in bacteriological culture media is discussed. The necessary conditions with regard to accuracy, are treated in detail, particularly in connection with the publication of van de Kamer.

So called “half distillation percentages” of acetic acid and propionic acid mixtures varying from 100% acetic acid to 100% propionic acid were determined experimentally and are given in the form of a table and a graph. The distillation technique and the apparatus used are accurately described. The values found are not to be considered as “constants” for the acids in question but depend very closely on the standardised distillation technique actually used.

The effect of the total acid concentration was clearly noticeable, and indeed, contrary to what is stated in the investigations of Virtanen and Pulkki, this effect was most marked for 100% acetic acid and mixtures rich in this acid. The concentration effect decreased for mixtures containing large amounts of propionic acid and could be neglected for 100% propionic acid.

On the basis of these results an analytical technique is described which makes it possible to determine small quantities of acetic acid and propionic acid (varying from 0.40–1.75 grams of these acids in 2000 ml of medium) with a very satisfactory accuracy.

This method has been tested experimentally on unknown quantities of these acids and the results obtained are given in a table.
Some urethane and diureide derivatives of α, β‐diarylethylamines
Authors: Neish W. J. P.
Published: September 2010

Some α,β‐diarylethylamines have been prepared. They react with ethyl chloroformate to yield N‐substituted ethyl carbamates and with hexa‐methylene diisocyanate to give diureides. The new carbamates and ureides are to be investigated as possible chemotherapeutic agents for cancer.
A new method for the preparation of derivatives of 2,2′‐dipyridyl
Authors: den Hertog H. J. , Mulder B.
Published: September 2010

When 2,6‐dibromo‐3,5‐diethoxypyridine is shaken with a mixture of ferric bromide and bromine in sunlight at 0°, it is converted in a yield of 95‐100 % into a derivative of 2,2′‐dipyridyl, i.e. 6,6′‐dibromo‐3,3′,5,5′‐tetraethoxy‐2,2′‐dipyridyl. It is shown that this reaction is a reversible process.

The structure of 6,6′‐dibromo‐3,3′,5,5′‐tetraethoxy‐2,2′‐dipyridyl is proved by its formation and by the fact that 2,2′‐dipyridyl was obtained when the bromine atoms and the ethoxy groups were eliminated.

6,6′‐Dibromo‐3,3′,5,5′‐tetraethoxy‐2,2′‐dipyridyl can be split up by allowing it to react with a mixture of sulphuric acid and fuming nitric acid, 6‐bromo‐3,5‐diethoxy‐2‐nitropyridine being formed. The last mentioned compound was converted into the dipyridyl derivative again when it was shaken with ferric bromide and bromine.
Synthesis of ketones by the action of α‐picolyl‐lithium on nitriles
Authors: Wibaut J. P. , de Jong J. I.
Published: September 2010

The action of α‐picolyl‐lithium on benzonitrile, acetontrile and α‐cyanopyridine is described. The ketimides of α‐picolyl phenyl ketone, α‐picolyl‐methyl ketone and α‐picolyl α‐pyridyl ketone are the primary products from which the corresponding ketones are eventually obtained. A method of preparation for α‐pyridyl α‐picolyl ketone, which is a new compound, is described.
Substituted ammonium carbamates from α,β‐diarylethylamines
Authors: Neish W. J. P.
Published: September 2010

Two new compounds believed to be substituted ammonium carbamates have been prepared by reacting α,β‐diphenylethylamine and α‐(4‐methoxy‐phenyl)‐β‐phenylethylamine with carbon dioxide.
3‐Methyl‐2‐butene carbonitrile
Authors: Ultée A. J.
Published: September 2010

A method is described by which 3‐methyl‐2‐butene carbonitrile, CH3. C(CH3): CH.CH2CN, can be made more simply and in better yield than by the known method.

The addition products of hydrogen chloride and isoprene, the primary hydrochloride, CH3.C(CH3): CH.CH2Cl and the tertiary hydrochloride, CH3.C(CH3)Cl.CH: CH2, give about 50% of the theoretical yield of the nitrile when treated with cuprous cyanide in benzene solution.
Ueber Dekahydroyobyrin und Tetrahydroyobyrin
Authors: Wibaut J. P. , Wibaut‐van Gastel A. J. P. , Buizer F. G.
Published: September 2010

Die katalytische Reduktion des Yobyrins mit Platin‐Oxyd als Katalysator wird quantitativ untersucht. Die Reduktion verläuft in zwei Stufen: zuerst bildet sich ein Tetrahydroyobyrin und danach das Dekahydroyobyrin, das schon vorher von Wibaut und van Gastel beschrieben worden ist. Ein Hexahydroyobyrin bildet sich unter diesen Bedingungen nicht. Die ultravioletten Absorptionsspektra des Yobyrins, des Tetrahydroyobyrins und des Dekahydroyobyrins wurden bestimmt.
The bromination of naphthalene III.: The influence of temperature and catalysts on the proportion of α‐ and β‐bromonaphthalene formed; the equilibrium α‐ ⇌ β‐bromonaphthalene
Authors: Wibaut J. P. , Sixma F. L. J. , Suyver J. F.
Published: September 2010

The bromination of naphthalene vapour in the presence of ferric compounds on pumice as a carrier has been studied between 250° and 650°. The ratio of α‐: β‐monobromonaphthalene has been determined in the reaction product. More β‐isomer is produced under the influence of the catalyst than in the non‐catalysed bromination. The same holds also for the bromination of liquid naphthalene under the influence of ferric chloride, ferric bromide or ferrous bromide between 85° and 215°.

The effect of the catalyst on the composition of the reaction product is a result of the reversibility of the reaction between bromine and naphthalene under these conditions. Although the equilibrium C10H8 + Br2 ⇌ C10H7Br + HBr, lies well over on the bromonaphthalene side, nevertheless an equilibrium between α‐ and β‐bromonaphthalene can be set up indirectly. The liquid equilibrium α‐ ⇌ β‐bromonaphthalene has been studied and the displacement of the equilibrium ratio with the temperature determined.
The mechanism of the catalytic alkylation of olefines and isoparaffins
Authors: Caviët M. , van Steenis J. , Waterman H. I.
Published: September 2010

A discussion is given of the reactions which occur in the catalytic alkylation of olefines and isoparaffins, taking into account the polymerizing tendency of the reacting olefines under the conditions applied in the alkylation. Carbonium ions are intermediates in this reaction.
Amides IV: The use of diacetimide in the Perkin reaction
Authors: Polya J. B. , Tardrew P. L.
Published: September 2010

Diacetimide may replace acetic anhydride in the Perkin reaction. Benzaldehyde and diacetimide yield cinnamamide with or without basic catalysts in good yield at 200‐220°. At 180° appreciable amounts of benzylidene bisamides are obtained, mainly benzylidene acetamide cinnamamide and benzylidene biscinnamamide.
Synthesis of vitamin A
Authors: Arens J. F. , van Dorp D. A.
Published: September 2010

“C18‐ketone” I has been converted into vitamin A‐aldehyde VI by the method involving the use of ethoxy acetylene. This aldehyde has been reduced to vitamin A by means of either Al‐isopropoxide and isopropanol, or with LiAlH4. Also vitamin A acid II could be converted into vitamin A by means of LiAlH4.
La p‐Hydroxypropiophénone, Ses Analogues et Leurs Dérivés
Authors: Buu‐Hoï Ng. Ph.
Published: September 2010

Dans ce travail, on étudie la chimie de la p‐hydroxypropiophénone et de ses dérivés, ainsi que celle des composés analogues dans la série du naphtalène, en particulier des 6‐acyl‐2‐naphtols. De nombreuses réactions ont éré effectuées sur ces corps: transposition de Claisen, réduction de Clemmensen, réactions de Pfitzinger, de Fischer, etc. …. De nombreuses substances nouvelles ont été obtenues, en particulier des 6‐alkyl‐2‐naphtols, des 6‐acyl‐2‐naphtols et leurs éthers, des quinoléines, et des indoles portant des fonctions phénol ou éther‐phénolique. Plusieurs composés mentionnés dans ce travail ont fait ou font l'objet d'études biologiques et cliniques.
L'extraction Fractionnée Systématique des Polymères
Authors: Desreux V.
Published: September 2010

The author describes a fully automatic apparatus for the systematic extraction of polymers.

He gives some typical curves obtained in the case of polythene, cellulose nitrate and cellulose acetate.
Viscosity of cellulose methyl ether solutions in ordinary and in heavy water
Authors: Aten A. H. W.
Published: September 2010

Viscosities are compared of cellulose methyl ether solutions in H2O and in D2O.
The copolymerisation of styrene and methyl methacrylate, styrene and butyl acrylate
Authors: Arlman E. J. , Melville H. W. , Valentine L.
Published: September 2010

The copolymerisations of styrene and methyl methacrylate, styrene and butyl acrylate, induced by the photo decomposition of benzoyl peroxide, have been studied and a full kinetic analysis of the reaction is presented. The introduction of small amounts of styrene lowers both the rate of initiation and the rate of copolymerisation to a marked extent, but further additions of styrene have relatively little effect. From a knowledge of the rate of initiation, derived from osmotic molecular weight data, and the overall rate, all the rate coefficients for the copolymerisations have been calculated. The termination constant for the reaction between styrene and methyl methacrylate radical (ktab = 2.06. 108) is much larger than that for styrene (ktaa = 8. 106) or methyl methacrylate (ktbb = 2.7. 107). Similarly for styrene (A)‐butyl acrylate (B), ktab = 5.7. 107 is much larger than ktaa = 8. 106 or ktbb = 1.8. 104. The derivation of these velocity constants is discussed critically, and a possible explanation of the large “crossed” termination constant, ktab, is offered, in terms of polar attractions of the two radicals.
Cyclo‐isomérisation de quelques benzylallylsulfones et de la phénylallylsulfone (les propriétés du groupe sulfonyle VIII)
Authors: Backer H. J. , Dost N.
Published: September 2010

La benzylallylsulfone, chauffée avec de l'acide sulfurique concentré, donne un isomère cyclique, dérivé du benzothiacyclohexane.

Afin d'étudier le mécanisme de cette cyclo‐isomérisation, les auteurs ont examiné l'influence de substituants dans le noyau aromatique. La présence de groupes nitro diminue la tendance à la cyclisation, ce qui s'accorde avec l'hypothèse qu'elle repose sur une substitution électrophile. Seules les nitro‐benzylallylsulfones o et p se cyclisent, et cela à des températures plus élevées. L'opposition de l'isomère m à la cyclisation peut étre imputée à l'effet désactivant du groupe nitro sur l'hydrogène qui devrait étre substitué.

Les méthylbenzylallylsulfones, chauffées avec de l'acide sulfurique, ne subissent pas la cyclisation attendue, par ce qu'elles sont sulfonées. Une solution sulfurique de fluorure de borium s'est montrée un catalyseur très actif pour la cyclo‐isomérisation. En présence de ce catalyseur, le dérivé méthylé m se cyclise aisément à la température ambiante. La cyclisation de l'isomère o se produit moins facilement et celle de l'isomère p n'a pas réussi.

La cyclisation de la phénylallylsulfone a donné un dérivé de thianaphtène.
On the state of oxalic acid dissolved in water
Authors: Snethlage H. C. S.
Published: September 2010

An apparatus for the determination of solubilities is described. The solubility of oxalic acid in water from 0°‐80° has been measured. The form of the temperature‐solubility curve shows that oxalic acid 2 aq. at the melting point is partially dissociated into anhydrous oxalic acid and water.

From the solubilities at lower temperatures the heat of solution is calculated, correcting for the electrolytic dissociation. The value is in good accord with that which was found experimentally.

It is concluded that in a solution of oxalic acid in water at temperatures below 70° practically all the molecules present are bound to (at least) two molecules of water, but that at higher temperatures an increasing dissociation into anhydrous acid and water takes place
Note sur l'acide 2,3,5‐Triiodo‐Benzoïque
Authors: Olivier S. C. J. , Combé W. P.
Published: September 2010

On a amélioré le mode de préparation de l'acide 2,3,5‐triiodobenzoïque, substance intéressante au point de vue physiologique. Le rendement qu'on obtient avec la nouvelle méthode est notablement supérieur aux rendements obtenus au moyen des diverses méthodes décrites jusqu'à présent.

Pour le composé à l'état pur on a trouvé le point de fusion de 230.8°‐231.2°, tandis qu'on trouve dans la littérature des chiffres variant de 223°‐224° à 225‐227°.
Recent progress in emulsion polymerization
Authors: Mark H.
Published: September 2010

Recent developments in the field of emulsion polymerization are discussed briefly. Emphasis is laid in particular on the application of various agents which promote polymerization at low temperatures, thus enabling the manufacture of rubbers with superior properties.
Condensation products of β‐ionone with 2‐methyl‐ and 2,4‐dimethylpyridine: An attempt to synthesize vitamin a
Authors: Arens J. F. , van Dorp D. A. , van Dijk G. M.
Published: September 2010

β‐Ionone has been condensed with the lithium derivatives of α‐picoline and of 2,4‐dimethylpyridine to form the carbinols VI (R = H) and VI (a) (R = CH3).

These condensation products were dehydrated with oxalic acid to VII. In the case of 2,4‐dimethylpyridine the polyene VII (R = CH3) was isolated in a cis and a trans form.

The original purpose of these experiments was to hydrolyse the pyridine ring in order to obtain derivatives of vitamin A. This, however, could not be achieved. The bases as such had no vitamin A activity.

The condensation products of α‐picoline with crotonic and sorbic aldehyde have also been prepared.
Contributions to the chemistry of ionones. II. A convenient laboratory synthesis of the isomethylionones)
Authors: Beets M. G. J.
Published: September 2010

An improved method is described for the preparation of pseudo‐iso‐methylionone and both isomethylionones, based upon the synthesis of Cherbuliez and Hegar6).
Colorants Polyméthiniques à Substitution Carboxylée dans la Chaîne
Authors: Bruylants P. , van Dormael A.
Published: September 2010

Les auteurs décrivent la synthèse de carbocyanines asymétriques, de mérocarbocyanines et d'une rhodacyanine portant un groupement carboxyle ou carbalcoxy en position β de la chaîne, aux dépens de dérivés oxalylméthyléniques du benzothiazole. Les données optiques des nouveaux colorants sont renseignées.
Derivatives of triaza‐indolizines
Authors: Cook J. W. , Gentles R. P. , Tucker S. Horwood
Published: September 2010

3‐Amino‐1,2,4‐triazole (I) has been found to react readily with suitable derivatives of cyclopentanone and cyclohexanone (for example, their hydroxymethylene derivatives and the corresponding keto‐esters) to form tricyclic compounds of the triaza‐indolizine class. The structural relationships between these various triaza‐indolizine derivatives are discussed.
Recherches sur les Alcaloïdes de L'erythrophleum: 13ème Communication): L'hydrolyse de la cassamine et de l'érythrophlamine
Authors: Engel B. G. , Tondeur R. , Ruzicka L.
Published: September 2010

Dans le mémoire qui précède, ainsi que dans deux brièves notes

L. Ruzicka, Pl. A. Plattner, B. G. Engel, Experientia 1, 160 (1945); B. G. Engel et R. Tondeur, Experientia 4, 430 (1948).

), nous avons donné la description de deux alcaloïdes nouveaux tirés de l'écorce d'Erythrophleum et de leurs sels. Nous désirons maintenant décrire les résultats de l'hydrolyse de ces deux alcaloïdes.
Some observations on tetraethylthiuram disulphide
Authors: Fredga Arne
Published: September 2010

Tetraethylthiuram disulphide (antabuse, abinyl) has the character of a pseudo‐halogen. In organic solvents it reacts with several metals giving salts of diethyldithiocarbamic acid. Copper gives at fir a able cupric salt, but on prolonged treatment with the metal a cuprous salt is obtained. The cuprous salt and an excess of disulphide immediately give the cupric salt. Diethylthiocarbamic acid, containing only one sulphur atom, gives only a cuprous salt.
Synthese von Farbstoff‐Antipoden für Histologische Färbungen I
Authors: Kögl F. , Faber J. G. , de Boer Z. C.
Published: September 2010

Die Frage, ob die Antipoden asymmetrisch gebauter Farbstoffe durch Wolle und Seide verschieden stark gebunden werden, ist bereits Gegenstand mehrerer Untersuchungen gewesen. In der vorliegenden Arbeit wurde die gleiche Fragestellung auf die histologische Färbung von tierischen Geweben übertragen. Zur Kernfärbung dienten spiegelbildliche Phenazin‐Derivate, die durch Kondensation von d‐ und l‐Campherchinon mit 2,3,6,7‐Tetraaminophenazin synthetisiert wurden. Die histologische Prüfung erfolgte bei normalen und bei malignen Geweben. Die durch d‐ und l‐Farbstoff hervorgerufenen Färbungen zeigten bei der visuellen Beobachtung praktisch keinen Unterschied in der Intensität.
The nature of the cessation reaction in free radical initiated additions of carbon tetrachloride to χ‐olefines: (Preliminary communication)
Authors: Kooyman E. C.
Published: September 2010

Evidence is presented that the main chain‐breaking step in the free radical initiated addition of carbon tetrachloride to χ‐olefines consists in the reaction between a trichloromethyl radical and the χ‐methylenic group of the olefine, which leads to the formation of a molecule of chloroform and a stabilized allyl‐type radical which is incapable of continuing the chain.
Sur la présence de lédol dans une cistacée (cistus ladaniferus L)
Authors: Sabetay Sébastien , Gilly Pierre
Published: September 2010

Les auteurs ont réussi à isoler à partir de l'essence de Ciste‐Labdanum de l'Estérel le lédol, alcool sesquiterpénique tricyclique tertiaire.
Dimerization of methylchavicol and of ethylchavicol with loss of hydrogen and ring formation. 1,2‐dianisylbenzene and 1,2‐diphenetylbenzene. A free radical as hydrogen acceptor?
Authors: van der Zanden J. M. , de Vries G.
Published: September 2010

The structure was determined of two products obtained respectively upon the polymerization of methylchavicol and of ethylchavicol. An attempt is made to give a plausible explanation of their formation.
The ethene‐water system
Authors: Diepen G. A. M. , Scheffer F. E. C.
Published: September 2010

The p‐t relations of the three‐phase equilibria in the system ethene‐water were determined from −15 to +20° C at pressures from 0 to 60 atmospheres. A dissociating compound, ethene hydrate, occurs, which is stable above the critical point of ethene and whose composition was determined by an indirect thermodynamic method and found to be C2H4.7 H2O.

The system exhibits metastable immiscibility. The corresponding metastable three‐phase equilibrium was measured from 0 to 9.7° C.
The solubility of water in supercritical ethene
Authors: Diepen G. A. M. , Scheffer F. E. C.
Published: September 2010

A method was worked out for determining the solubility of water in the fluid phase in the system ethene‐water, in which a solid compound, ethene‐hydrate, occurs. Several measurements were performed at 15.0 and 25.0° C. The solubility of water in the liquid phase was even found to attain twenty times the theoretical value.
L'action du diazométhane sur le bis‐méthylsulfonyl‐nitrométhane (les propriétés du groupe sulfonyle X)
Authors: Backer H. J.
Published: September 2010

Le diazométhane réagissant sur le bis‐méthylsulfonyl‐nitrométhane donne naissance à un produit inflammable, qui manque des propriétés propres à un dérivé méthylé.

L'auteur suppose que, sous l'influence des sulfonyles, le groupe nitro fixe le diazométhane, en conduisant, après la perte d'azote, à l'époxyde d'une imine. A froid déjà, le produit se dédouble en aldéhyde formique et bis‐méthylsulfonyl‐(iso) nitrosométhane.

Le schéma, proposé pour la réaction du diazométhane, est appuyé par les résultats de celle du diazoéthane.

Le composé (iso)nitroso, qui est peu stable en solution aqueuse, donne des dérivés incolores de méthyle et d'acétyle. Le composé est un acide, dont les sels sont colorés en jaune. L'auteur admet pour ces sels une structure nitroso, qu'il attribue à l'influence des groupes voisins de sulfonyle.
The stability of hydrocyanic acid at elevated temperatures
Authors: Sporzynski A. , Salter H. L.
Published: September 2010

Explosions of hydrocyanic acid during storage are believed to result from the rapid uncontrolled polymerization of the acid, leading to a sudden increase in pressure of the gaseous concomitants.

Cobalt oxalate or its admixture with nickel oxalate constitute outstanding stabilizers for hydrocyanic acid and are particularly effective in reducing risk of explosion (American and British patents have been claimed).

Analysis indicates that their action is due to a liberation of oxalate ion into solution by hydrocyanolysis.

The deterioration of hydrocyanic acid may be conveniently observed by a measurement of conductivity changes.

Water is a main factor in deterioration, a proportion over 5% impairing to a very high degree the stability of hydrocyanic acid.

An unprotected steel surface also exercises an adverse effect which may be eliminated by suitable (e.g. oxalate) coatings.
The action of atomic hydrogen on hexadecene‐1, hexadecane and linseed oil
Authors: Boelhouwer C. , Heertjes P. M. , Houtman J. P. W. , van Steenis J. , Waterman H. I.
Published: September 2010

The reaction of hydrogen atoms, prepared according to Langmuir by passing a stream of hydrogen over a glowing tungsten wire, with liquid hexadecene‐1, hexadecane and linseed oil is described.

With hexadecane saturated higher molecular hydrocarbons are formed. With hexadecene hydrogenation as well as polymerization occurs, the polymerization products being partly unsaturated. With linseed oil conjugation of the double bonds occurs besides hydrogenation and polymerization, but only to a small extent.

Interaction of H‐atoms with the double bond proceeds faster than with the saturated part of the molecule, though the last reaction definitely makes a contribution to the overall reaction. Formation of unsaturated products from the corresponding saturates hardly occurs.

Other literature is reviewed in connection with the present work.
Polarographic investigation of mimosine
Authors: Bonting Sj. L. , Schepman F. R.
Published: September 2010

A polarographic investigation of mimosine was made in order to obtain more information on its polar structure. The polarographic behaviour of mimosine is abnormal, but it is possible to give a reaction scheme explaining these phenomena.
Décomposition Spontanée du Bis‐Méthylsulfonyl‐Isonitrosométhane: (Les propriétés du groupe sulfonyle XI))
Authors: Backer H. J.
Published: September 2010

Le bis‐méthylsulfonyl‐isonitrosométhane est un produit peu stable qui, à la température ambiante, subit des décompositions compliquées. On a pu isoler ou démontrer sept produits de décomposition.

Un de ces produits est la diméthyldisulfone, composé inconnu jusqu'ici et difficilement accessible. On explique sa naissance en admettant un doublement du radical méthylsulfonyle.

Un produit plus compliqué, dont la formation accompagne celle de la disulfone, présente la formule empirique C4H10O5N2S2. On y peut attribuer la composition d'un dérivé d'oxadiazolidine (tétrahydrofurazane).
L'action de Diazométhane sur le Bis‐Méthylsulfonyl‐Isonitrosométhane: (Les propriétés du groupe sulfonyle XII )
Authors: Backer H. J.
Published: September 2010

Le diazométhane réagit sur le bis‐méthylsulfonyl‐isonitrosométhane (III) de façon compliquée; on a pu isoler cinq produits à l'état pur. Les produits primaires sont l'éther méthylique (IV) et un isomère instable que nous considérons comme un dérivé d'éthylène‐hydroximine (V). Le chauffage de cet isomère donne naissance à la diméthyldisulfone.

L'action prolongée du diazométhane sur l'éther méthylique (IV) conduit, par l'intermédiaire d'une triazoline peu stable (VI), à deux produits stables: un dérivé d'éthylène‐méthoximine (VII) et un triazole (IX). On peut diriger la décomposition de la triazoline (VI) de telle façon que l'on obtient exclusivement soit l'un soit l'autre des deux produits finaux (VII et IX).
The adsorption of carbon disulphide vapour flowing through a tube filled with activated charcoal
Authors: Vreedenberg H. A.
Published: September 2010

The course of the adsorption of carbon disulphide vapour from a mixture of air and CS2, which flows through a long tube with activated charcoal, is calculated as a function of the time and of the place in the tube. For this purpose the analogous theory on the increase of the temperature of a solid in a furnace, through which a hot liquid or gas flows, can be used. The results of the theory are recorded in fig. 2 to 4 inclusive, the meaning of which follows from the formulae (9), (14) and (15) (see further the elucidation in § 4). Some of the conclusions, which can be derived from them, are compared with the results of various experiments.
On the theory of ionic conductivity in crystals
Authors: Haven Y.
Published: September 2010

A survey is given of the existing theories of the ionic conductivity in crystals.

The experimental log x ‐ 1/T curves usually consist of two straight parts with different slopes. This shape can be explained by several mechanisms (Smekal, Jost and others). For the conductivity of mixed crystals, where the solute introduces additional vacancies, we derived a formula (formula III) which gives the conductivity as a function of the concentration of the solute and of the temperature. This formula also explains the kink in the conductivity curve.

A method has been given which makes it possible to choose between the explanations for the kink in the conductivity curve in a given case. It is based on an analysis of the transition region between the two straight parts of the curves, and was applied to the conductivity of Li‐halides and LiHl‐MgHl2 mixed crystals. It was found that in this case the kink in the conductivity curves could be described by formula III and not by the mechanisms proposed by others.
Determination of riboflavin according to the lumiflavin method
Authors: Jansen A. P.
Published: September 2010

A method is described for the determination of riboflavin by the lumiflavin method. The results are compared with those obtained by microbiological assay.
Bromo‐derivatives of 3‐hydroxypyridine
Authors: Den Hertog H. J. , Schepman F. R. , de Bruyn J. , Thysse G. J. E.
Published: September 2010

Descriptions are given of methods for the preparation of eight bromoderivatives of 3‐hydroxypyridine.

2,4,6‐Tribromo‐3‐hydroxypyridine was obtained as reaction product in the bromination of 3‐hydroxypyridine in aqueous solution. When the bromination was carried out with the bimolecular quantity of bromine in pyridine as a solvent, 2,6‐dibromo‐3‐hydroxypyridine (m.p. 163°) could be isolated. We have not been able to confirm the observations of Fischer and Renouf who report the formation of a dibromo‐3‐hydroxypyridine (decomposition point: 200°) by the action of bromine water on 3‐hydroxypyridine.

Finally some reactions of 2,4,6‐tribromo‐3‐hydroxypyridine are described.
Stabilisation of montmorillonite sols by chemical treatment. Part. II. Effect of polymetaphosphates, sodium metasilicate, oxalate, citrate and orthophosphate on Na and Ca montmorillonite sols
Authors: van Olphen H.
Published: September 2010

Three different causes are concluded to contribute to the stabilisation of montmorillonite sols by polymeric phosphates, sodium metasilicate and sodium oxalate:

a charging effect due to adsorption of the anions to the edges of the micelle plates.

a decrease of the sodium ion activity in the mixture of stabilizer and flocculating salt.

an inactivation of strongly flocculating calcium ions by complex formation or precipitation.
The mechanism of the reaction between ozone and aromatic compounds. (Preliminary communication)
Authors: Wibaut J. P. , Sixma F. L. J. , Kampschmidt L. W. F. , Boer H.
Published: September 2010

The velocity of ozonisation of a number of aromatic compounds has been determined. Boron trifluoride and aluminium chloride exert an accelerating influence on ozonisation. On the basis of our experimental results it is probable, that the ozonisation of aromatic compounds takes place by an electrophilic reaction mechanism.
Rate of dissolution of solid substances. Part II (Chemical dissolution)
Authors: van Krevelen D. W. , Krekels J. T. C.
Published: September 2010

The rate of dissolution of benzoic acid granules in alcaline aqueous solutions has been studied. A formula of the kinetics of this chemical dissolution process has been derived. Mass transfer coefficients for film‐like flow of the dissolving agent can be correlated by the same dimensionless equation as in the physical dissolution process.
Synthesen auf dem Auxin‐Gebiet. III. Ein einfaches Strukturanalogon von Auxin‐a. 41. Mitteilung über pflanzliche Wachstumsstoffe
Authors: Kögl F. , Ultée A. J.
Published: September 2010

Die vorliegende Arbeit behandelt eine Synthese, bei welcher an den Kern des Cyclopentens durch systematischen Aufbau die dem Auxin‐a zugeschriebene hydroxyl‐ und carboxyltragende Seitenkette angegliedert wurde. Der erhaltenen Säure bzw. ihrem δ‐Lacton fehlen die sekundären Butylgruppen des natürlichen Phytohormons. Hiermit dürfte die Unwirksamkeit im Avena‐test zusammenhängen, wie dies bei dem in der vorigen Mitteilung dieser Reihe beschriebenen, einfachen Analogon von Auxin‐b ebenfalls konstatiert wurde. Bei dem anscheinend einheitlichen Kristallisat handelt es sich um eines der vier theoretisch möglichen Racemate des Lactons. Während der leichte übergang in die freie Säure an das Verhalten von Auxin‐a‐lacton erinnert, scheint der Modellstoff durch Bestrahlung mit ultraviolettem Licht nicht verändert zu werden. Zur weiteren Klärung ist daher die Darstellung der stereoisomeren Verbindungen erforderlich.
A new synthesis of aryl‐aliphatic alcohols: III. Application of the method to some natural and synthetic compounds
Authors: Drukker E. A. , Beets M. G. J.
Published: September 2010

The method described in the first two papers of this series 1) is applied to a number of aryl‐alkenes and some corresponding carbinols.
A new method for the synthesis of furan derivatives: III ). Pyrolysis of δ‐sultones with two double bonds in the ring
Authors: Morel Th. , Verkade P. E.
Published: September 2010

In this paper directions are given for the preparation of furan derivatives by the pyrolysis of δ‐sultones with two double bonds in the ring. The examples relate to nine of the ten possible constitutional types.
Dissociation and tautomerism of some quinone monoximes
Authors: Havinga E. , Schors A.
Published: September 2010

An analysis by counter‐current distribution of the substance of m.p. ∼ 140° C, described as 3‐chloro‐nitrosophenol by Hodgson1) and described as 3‐chloro‐quinone monoxime by other authors4) 5) 2) gave support to the opinion already expressed 2) that this substance has a complex nature. The main component found in the solution of the substance was identical with 3‐chloro‐quinone monoxime (m.p. 182°).
Thermodynamic properties of mixtures of alkanes differing in chain length, III: The system hexane‐dodecane
Authors: van Der Waals J. H.
Published: September 2010

Heats of mixing at 20° C are given for the system hexane‐dodecane. The results are in agreement with Brønsted's principle of congruence as derived from previous heat of mixing data on other binary alkane systems. The entropy of mixing in the present system is somewhat smaller than that following from Guggenheim's theory for athermal mixtures.
Amides VII. The use of diacylimines in the perkin reaction
Authors: Polya J. B. , Spotswood T. M.
Published: September 2010

The base catalysed reaction between diacylimines and aromatic aldehydes or furfural affords good yields of the expected unsaturated amides. E.g. 3‐(furyl‐2′)‐2‐methyl‐2‐propenoic amide, may be prepared by this method with a yield of 71%. Chloral and 3‐(furyl‐2′)‐2‐propenal give poor yields of the expected unsaturated amides but these yields are higher than those obtained through the normal Perkin reaction. Some aspects of the mechanism of the Perkin reaction are discussed in the light of new experimental evidence.
Titration of adsorbed acids IV
Authors: Tendeloo H. J. C. , Mans A. E. , de Hoogh G.
Published: September 2010

The titration curves of adsorbed isomeric acids are determined. The three hydroxy‐benzoic acids do not show any difference in the adsorbed state notwithstanding the isomerism and difference in acidity.

The adsorption of the stereo‐isomerides fumaric and maleic acid results in the difference in acidity between the two acids being strongly reduced; the adsorption‐isotherms of the two isomerides show, that the adsorption of maleic acid is less than that of fumaric acid.

We considered hitherto the adsorbed acids as polybasic acids, but it is also possible to take another point of view i.e. the theory of the Donnan‐equilibrium. The fact that the titration curves of adsorbed salicylic acid obtained with NaOH and with Ca(OH)2, do not coincide proves at least qualitatively that we have to do with the distribution of ions between the adsorbed phase and the solution according to the Donnan‐equilibrium.

By increasing the amount of adsorbent, primarily the adsorbed acid becomes gradually more weak, thereafter the acidity of the acid appears to increase again.
Oxydation des tétrathioorthocarbonates aromatiques: (Propriétés du groupe sulfonyle XVI)
Authors: Backer H. J.
Published: September 2010

L'oxydation ménagée des tétrathioorthocarbonates de phényle et de p‐tolyle, en solution rigoureusement anhydre, conduit aux diaryldisulfones correspondantes. On peut caractériser ces disulfones en les décomposant au moyen de pipéridine; cette scission donne le benzène (toluéne)sulfo‐pipéridide et le benzène(toluène)sulfonate de pipéridine.

Apparemment ni les esters aliphatiques, ni les esters aromatiques de l'acide tétrathioorthocarbonique ne donnent finalement des tétrasulfones. La cause de ce fait peut être la surcharge à laquelle l'atome central serait exposé de la part des quatres groupes égaux, avides d'électrons.
Separation of thorium from uranium
Authors: Krishnamurty K. V. S. , Rao B. H. S. V. Raghava
Published: September 2010

Anisic acid has been found to be a suitable reagent for the separation of Thorium from Uranium. From neutral solutions thorium may be freed from twice its quantity of uranium in a single precipitation and about eight times of uranium after a second precipitation.
Kinetic analysis of organic halides. Part III. Analysis of low molecular polyhalides
Authors: Salomon G. , Ultée A. J.
Published: September 2010

The reactions of polychlorinated ethanes and propanes, with aniline and piperidine, have been studied and the results are compared with data obtained previously for monohalides.

Vicinal polychlorides are stable towards aniline at 100° C, but reactive with piperidine at 100° C. Certain polychlorides with >CCl2 or ‐CCl3., groups are distinguished from the former by their ease of reaction with piperidine at room temperature.

Mixtures of monochlorides and polychlorides can be subjected to kinetic analysis by a combination of these tests. It is possible to recognise different groups, but a quantitative kinetic separation of the fractions can not always be achieved.

Application of this method to chlorinated paraffins with 42 % Cl and 70 % Cl reveals that the distribution of chlorine in these molecules is not at random. The reactivity of these chlorinated paraffins indicates the occurrence of > CCl2 groups.
Kinetic analysis of organic halides. Part. IV. Analysis of macromolecular polyhalides
Authors: Salomon G. , Koningsberger C.
Published: September 2010

Chlorination products derived from natural rubber and some synthetic polymers have been subjected to kinetic analysis with aniline at 100° C and piperidine at 20° C. The influence of the chlorinating agent on the structure of the reaction products has been elucidated.

It is shown that allylic chloride groups, the rubber dichloride

magnified image

and rubber polychlorides can be identified and separated kinetically.

By a combination of kinetic and infrared analysis the structure

magnified image

can be proved as the primary reaction product of direct chlorination.
The directive influence of the N‐oxide group during the nitration of derivatives of pyridine‐N‐oxide
Authors: den Hertog H. J. , Kolder C. R. , Combé W. P.
Published: September 2010

The nitration of some mono‐substituted derivatives of pyridine‐N‐oxide containing a bromine atom, an ethoxy‐ or a methyl‐group in positions 2 or 3, has been investigated.

When these compounds are heated With a mixture of fuming nitric acid and sulphuric acid, a nitro‐group is introduced into the 4‐position. It appears that the course of the nitration is not influenced by the presence of the bromine atom, the ethoxy‐ or methyl‐group in the nucleus. A 4‐nitro‐compound is obtained even from 2‐ethoxypyridine‐N‐oxide, the nitro‐group entering the meta‐position with respect to the strongly ortho‐para directing ethoxy‐group.
Polymerisation of methylchavicol: Dimerisation coupled with hydration
Authors: van der Zanden J. M. , de Vries G.
Published: September 2010

The action of 43 % sulphuric acid on methylchavicol

has afforded metanethole, m.p. 135°, along with a mixture of substances, which can be shown to contain in all probability isoanethole and from which two products melting at 76.5° and 94°, respectively, could be isolated. The structures of these two products has been determined.
The U.V. absorption spectra of p. Amino‐salicylic acid and some related compounds (I)
Authors: v. d. Stelt C. , Rekker R. F. , Nauta W. Th.
Published: September 2010

The U.V. absorption spectra of p.amino‐salicylic acid were measured both in water and in ethanol. The results of these measurements show that there is no discrepancy between the work ofWaya.o. andDraina.o. as was suggested by the latter authors.

In addition the U.V. absorption spectra of some related compounds were measured.
1,1‐Dichlorodienes‐1,3: I. Preparation of 1,1‐dichlorobutadiene and of 1,1‐dichloro‐n‐hexadiene
Authors: Kooyman E. C.
Published: September 2010

Pyrolysis of 1,1,1,3‐tetrachlorobutane at 450‐460° C gives 1,1‐dichlorobutadiene‐1,3; from 1,1,1,3‐tetrachlorohexane 1,1‐dichlorohexadiene‐1,3 was obtained.

These new dienes have an ultra‐violet absorption maximum at 2430 and 2465 Å, respectively. They polymerize to viscous oils on standing, but do not react with maleic anhydride or sulphur dioxide.
La purification de l'acide ptéroylglutamique: Acide folique synthétique
Authors: Backer H. J. , Houtman A. C.
Published: September 2010

Une modification de la méthode de Waller3) pour la préparation de l'acide ptéroylglutamique cristallisé est proposée et motivée.