bluuebunny/crossref_metadata_2025 huggingface dataset:
Die Strömungsdoppelbrechung in Lösungen Makromolekularer Substanzen
Authors: Hermans J. J.
Published: September 2010

The birefringence of flow in solutions of macromolecular substances is discussed briefly from the point of view of flexible, randomly kinked molecules. The formulae obtained elsewhere5) are compared with experiments mentioned in the literature. The agreement is satisfactory. These formulae are based on the model of flexible, randomly kinked molecules. It would seem to us that the experimental evidence must be regarded as a substantial support for this model.
The azo chromophor (XI). (Steric hindrance of the resonance)
Authors: Blumberger J. S. Petrus
Published: September 2010

In the case of a large number of vicinally substituted azo dyes derived from 1‐aminonaphthalenedisulphonic acid‐4,8, and ‐6,8, and from 1‐hydroxynaphthalene‐sulphonic acid‐4, it was shown that in the great majority of cases this substitution is accompanied by an often considerable hypsochromic effect. This configuration is not favourable for a coplanar position of benzene ring and azo group and therefore impedes the mesomerism.

In the dye p‐nitrobenzene‐azo‐(dimethyl)‐o‐toluidine there is also steric hindrance of the coplanar position of amino group and benzene ring and here also a negative shift of the edge of the absorption band occurs compared with the dye p‐nitrobenzene‐azo‐(dimethyl)‐aniline.
Quelques Dérivés de L'acide 2‐Aminothiazol‐5‐Sulfonique
Authors: Backer H. J. , Buisman J. A. Keverling
Published: September 2010

Pour étudier leurs propriétés chimiothérapeutiques, les auteurs ont préparé la 2‐aminothiazol‐5‐sulfonamide et quelques‐uns de ses dérivés. Ils donnent les raisons qui militent en faveur de la structure qu'ils assignent à ces composés, quoique la position du groupe sulfonamide n'ait pas été établie avec certitude.
Syntheses of 3,4‐dimethylpyridine, 2,3‐dimethylpyridine and 2‐methyl‐3‐ethylpyridine
Authors: Wibaut J. P. , Kooyman E. C.
Published: September 2010

A synthesis is given of 2,3‐dimethylpyridine, 3,4‐dimethylpyridine and of 2‐methyl‐3‐ethylpyridine. The starting material is α‐methyl‐ or α‐ethyl‐acetylacetic acid ester. The yields calculated on the basis of the starting materials mentioned amount to about 35 percent.
Inhibition and induction
Authors: Jorissen W. P.
Published: September 2010

The acceptors investigated until now retard the oxidation of the inductor when they do not react with the oxidation product of the latter and when other reactions do not occur which complicate the result. On the other hand substances which retard the oxidation of an auto‐oxidizable substance need not necessarily be acceptors.
Untersuchungen über Pilzfarbstoffe XV. ): Über Phomazarin II
Authors: Kögl F. , Quackenbush F. W.
Published: September 2010

Auf Grund neuer Abbauergebnisse ist anzunehmen, dass in Phomazarin, dem aus den Kulturen von Phoma terrestris Hansen isolierten rotgelben Farbstoff ein Derivat eines 1‐Aza‐anthrachinons vorliegt. Auch über die Stellung der acht Substituenten liessen sich nähere Angaben machen, sodass die grosse Zahl der in Betracht kommenden Isomeren auf zwei sehr wahrscheinliche Strukturformeln eingeschränkt werden kann. Phomazarin ist ein neuartiger Naturstoff; auch unter den künstlich dargestellten Farbstoffen findet sich keine analoge Verbindung.
Auslösungskrystalle und Zwillingsbildung in Rekrystallisiertem Aluminium
Authors: Burgers W. G. , May W.
Published: September 2010

Aluminium plates with large crystals, obtained by recrystallization of finely grained material, show many “pointed” crystals: cf. fig. 1, 9 and 11. Such crystals have grown as a result of “stimulation” by another crystal, in this way that their growth did not start until another crystal, the growth of which had started previously, reached the nucleus of the “stimulated” crystal. In order to obtain a measurable size, the velocity of growth of the stimulated crystal must, at least at the beginning, be larger than that of the stimulating crystal.

X‐ray investigation has shown that the relation between the orientations of both crystals is practically always that of a spinel‐twin: cf. fig. 5. Twinning is thus rather common in recrystallized aluminium. It has only not be generally recognized on account of the absence of straight twin boundaries, a consequence of the difference in velocity of growth of stimulating and stimulated crystal.

The question is discussed as to the physical aspect of “stimulation” in the above given sense. For the moment the following has been suggested: Stimulating and stimulated crystal have an octahedral plane (111) and in this plane the direction [110] in common. This plane and direction are those used in the glide‐process of the cubic face‐centred metals. Suppose gliding along a definite combination has taken place in a lattice‐region: this means, according to the now prevalent conception, that “dislocations” have moved along this plane over certain distances and are then arrested, together with their fields of stress, at definite structural “irregularities” (flaws etc.). Suppose again there is a growing crystal, which by chance has an octahedral plane in twin orientation with regard to the active glide‐plane of the lattice‐region considered above. Then as soon as contact is established between the growing crystal and the deformed lattice‐region, something like a “discharge” of the arrested dislocations along the octahedral plane of the growing crystal might perhaps be conceived. As a consequence the deformed region may attain the capacity to grow. Why, however, its velocity of growth is larger than that of the stimulating crystal, is not yet clear. Perhaps the lattice of the stimulated crystal is more “perfect” than that of the stimulating crystal.

The possibility must be kept in mind that the process described by us as a stimulation does not exist in reality and is actually caused by an “error” in the deposition of a layer of atoms along the octahedral plane, giving rise to the occurrence of the twin orientation. In that case it seems still more difficult to imagine in which way the experimentally observed difference in velocity of growth of both twin‐parts comes into existence. Perhaps this second mechanism is the normal one for such metals as nickel, copper, nickeliron, which twin frequently, producing twin lamellae with straight boundaries.
The dielectric constant of crystalline powders
Authors: Böttcher C. J. F.
Published: September 2010

A formula is derived with the aid of which it is possible to compute the dielectric constant of a compact crystal from that of a crystalline powder.

The formula is checked by means of experimental data.
The reactivity of the group ‐N: N. C: C‐ in 2‐phenylazocrotonic acid esters. (The reaction between α‐halogen ketones and derivatives of phenylhydrazine I)
Authors: van Alphen J.
Published: September 2010

2‐Phenylazocrotonic acid ethyl and methyl ester were investigated as examples of compounds containing a conjugated system consisting of an NN double bond conjugated with a C‐C double bond. It was found that ozone combines by addition to the CC double bond, hydrogen and hydrochloric acid in the 1:4 position, the last substance splitting off alcohol at the same time and forming 1‐phenyl‐3‐methyl‐4‐chloropyrazolone‐5, while the action of phenyl magnesium bromide was exactly comparable with the action of the same substance on azobenzene.
Quelques Sulfanilamidopyrimidines Substituées
Authors: Backer H. J. , Grevenstuk A. B.
Published: September 2010

Poursuivant leurs recherches sur les sulfanilamidopyrimidines, les auteurs en ont préparé plusieurs dérivés, substitués par les groupes hydroxy, méthyle, méthoxy, méthylthio, phénylthio et anilino. L'activité chimiothérapeutique des nouveaux composés a été examinée.
Untersuchungen über Indolderivate. III: Die Reaktion Zwischen Methyl‐(β‐Phenyl‐α‐Bromäthyl)keton und Primären und Sekundären Aromatischen Aminen
Authors: Janetzky E. F. J. , Verkade P. E.
Published: September 2010

Es wird die Reaktion zwischen Methyl‐(β‐phenyl‐α‐bromäthyl)keton und Anilin bzw. Monomethylanilin untersucht. Ausgehend von den beiden hierbei gebildeten α‐Arylaminoketonen. 1‐Phenyl‐2‐phenylamino‐butanon‐(3) und 1‐Phenyl‐2‐phenylmethylamino‐butanon‐(3), werden mehrere Indolderivate hergestellt.

Das gesamte Tatsachenmaterial bestätigt die Anschauungen über den Mechanismus der Indolbildung aus α‐Arylaminoketonen, die in den Abhandlungen I und II entwickelt worden sind.
The atomic arrangement in solid sodium nitrate at high temperatures
Authors: Ketelaar J. A. A. , Strijk B.
Published: September 2010

Different possibilities for the arrangement and the constitution of the NO3‐group in the high temperature modification of solid sodium nitrate are considered. From the intensities on X‐ray diagrams both from a powder and from a rotating crystal taken at a temperature just below the melting point of sodium nitrate the plane rotational symmetry of this group is definitely confirmed, while other models are found to be inconsistent with the observations.
Des Quinoléines Substituées IV. Méthoxyphényl‐ et méthoxynaphtyl‐2‐quinoléines
Authors: Buu‐Hoï Ng. Ph. , Cagniant Paul
Published: September 2010

Dans ce travail, on étudie un groupe de dérivés quinoléiques nouveaux obtenus en appliquant la réaction de Pfitzinger à une série d'acétophénones et d'acétonapthones méthoxylées. Les corps ainsi préparés sont souvent doués d'une activité pharmacodynamique intéressante analogue à celle de l'atophan et de ses dérivés.
An interrupted direct‐current arc for spectrochemical analysis
Authors: Schmidt R. , Schuringa A.
Published: September 2010

An improved form of an interrupted are developed by one of the authors is described. Oscillograms are shown to elucidate the performance of the arrangement.
Action des trois nitrobenzènesulfochlorures sur la guanidine
Authors: Backer H. J. , Moed H. D.
Published: September 2010

L'action du p‐nitrobenzènesulfochlorure sur la guanidine en solution faiblement alcaline produirait, selon Winnek, une sulfonamide (la p‐nitrophénylsulfonyl‐guanidine), tandis que Karrer et Epprecht ont obtenu un sel (le p‐nitrobenzènesulfonate de guanidine). Une étude détaillée de cette réaction nous a permis d'expliquer cette différence de résultat. Les observations des auteurs précités sont, toutes les deux, correctes, mais incomplètes. Le produit principal est, soit la sulfonamide, soit (en solution plus alcaline) le sel. Mais, à cǒté de la sulfonamide, il se forme, en quantité notable, une disulfonamide (la bis‐p‐nitrophénylsulfonyl‐guanidine) et, en milieu assez alcalin (K. et E.), on obtient les produits de décomposition des deux sulfonamides.

La p‐nitrophénylsulfonyl‐guanidine engendre, en solution alcaline, la p‐nitrophényl‐guanidine; la bis‐p‐nitrophénylsulfonyl‐guanidine donne naissance à des quantités équimoléculaires de p,p'‐dinitrophényl‐amine et de cyanamide. II se forme, dans les deux cas, la quantité théorique d'anhydride sulfureux.

En vue de la comparaison, les auteurs ont examiné ensuite l'action des deux nitrobenzènesulfochlorures isomères (o et m) sur la guanidine. Ils donnent également une sulfonamide et une disulfonamide.
The excretion of pyridine compounds
Authors: Roggen J. C.
Published: September 2010

Das Vorhandensein eines merkwürdigen Derivats der Nicotinsäure im Harn hängt vom Diät ab; für die Klinik hat die quantitative Bestimmung dieses Derivats keinen Wert. Es begleitet das B‐complex.
The Raman spectrum of hexachlorocyclopentadiene C5Cl6
Authors: Gerding H. , Prins H. J. , van Brederode H.
Published: September 2010

The Raman spectrum (frequency shifts and polarization) has been determined of liquid C5Cl6 which was prepared for the first time by Prins, and has the probable structure of hexachlorocyclopentadiene, according to its chemical properties. The polarization measurements are rather incomplete, owing to the strong absorption in the blue region of the spectrum, extending until about 1000 cm−1 beyond 4358 in the direction of longer wave‐lengths.

Strong evidence is present in favour of this C5Cl6 possessing the structure of hexachlorocyclopentadiene. Probably it has the symmetry C2v with a plane ring. Values for the valency vibrations of the ring in C5Cl6 are given.
The Raman spectra of some polychloro compounds of formula C6Cl8
Authors: van Brederode H. , Gerding H. , Prins H. J.
Published: September 2010

The Raman spectra (frequency shifts and depolarization ratios) of three cyclical compounds of formula C6Cl8 (melting points 45°, 92° and 183°) are given.

Indications about the structure of the three molecules could be obtained, mainly on the basis of the depolarization ratios of the two “v (C = C)” Raman lines belonging to each molecule and on the occurrence of other depolarized Raman lines in the frequency region exceeding 900 cm−1.

The experimental results are satisfactorily explained by assuming the following formulae: magnified image formulae II. III, V being indistinguishable in the Raman effect.
Repulsive forces between milk‐fat globules
Authors: van Kreveld A.
Published: September 2010

The repulsive forces between milk‐fat globules as apparent from microscopic counting are shown to be definitely influenced by the addition of a number of chemicals. Some data provide evidence of the long range of action of these forces. An explanation is given of the failure of countings by Svedberg et al. to establish interaction.
Derivatives of 1‐chloro‐2‐cyano‐4‐nitrobenzene
Authors: Hartmans H. M. A.
Published: September 2010

Baudet

H. Ph. Baudet, Rec. trav. chim. 43, 710 (1924).

) studied the velocity of decomposition of 1‐chloro‐2‐cyano‐4‐nitro‐benzene with sodium alcoholate. He found that this compound reacted with sodium alcoholate about five times more slowly than 1‐chloro‐2: 4‐dinitrobenzene. This investigation has now been continued with a study of the reactions of 1‐chloro‐2‐cyano‐4‐nitrobenzene with some primary amines including β‐hydroxyethylamine, αβ‐diaminoethane, hydrazine and sodium mono‐ and di‐sulphides.
Iodometrical estimation of glucose in urine and blood
Authors: Noyons E. C.
Published: September 2010

It is possible to determine quantitatively small quantities of glucose by means of an alkaline iodine solution; under certain circumstances this method may also be applied to the determination of glucose in urine and blood.
Colorimetric determination of tocopherol: The influence of cholesterol on the reaction between dl‐α‐tocopherol and ferric chloride‐dipyridyl
Authors: Emmerie A.
Published: September 2010

The author has investigated the influence of cholesterol on the reaction between dl‐α‐tocopherol and the ferric chloride‐dipyridyl reagent.

The influence of cholesterol as found by some investigators must have been caused by an impurity in the cholesterol.
Potentiometric characterization of colloidal systems
Authors: de Bruijn H.
Published: September 2010

After having mentioned that special concentration effects occur in the potentiometric characterization of colloidal systems, which effects can according to Rabinovitch, Du Rietz and Loosjes be reduced to electrical effects at the salt‐bridge used in the measurements, a brief review is given of the concepts necessary for a discussion of this problem.

It is next shown that the electrical effects at the salt‐bridge are very closely related to the potential difference in the diffuse part of the ionic double layer of the suspended particles.

An explanation of the occurrence of salt‐bridge effects is given, starting from the hypothesis that a potential difference occurs in the boundary of a sol.

Finally it is mentioned how pX measurements (for example pH measurements in soil suspensions) ought to be carried out in colloidal systems in order to render a clear interpretation possible.
Experiments in harmony (steady state): The Teorell equations
Authors: Straub J. , van Eijk M. , de Wilde J. H. , Hekker Th.
Published: September 2010

The Teorell equations (1935) seemed to fit on earlier diffusion experiments of Straub. These experiments have now been repeated and extended, and the results compared with numbers calculated on the base of the Teorell equations. The correspondence was satisfactory.
On electro‐osmosis and streaming‐potentials in diaphragms
Authors: Overbeek J. Th. G. , Wijga P. W. O.
Published: September 2010

It is mentioned that the streaming‐potential E/P and the volume of liquid transported by electro‐osmosis v/i are equal, independent of the structure of the diaphragm and independent of its surface conductance. The value of these ratios which, in the absence of surface‐conductance equals ϵζ/4 πηλ diminishes when surface‐conductance is present. This decrease can be accurately taken into account when the diaphragm consists of a single capillary of constant diameter. In the case of real diaphragms, consisting of a network of capillaries of different shape and dimensions the correction factor for surface‐conductance cannot be computed! It has been common practice to estimate the correction factor from the ratio of the observed to the calculated electric resistance of the diaphragm. This procedure is shown to be erroneous, leading to values of the ζ‐potential that are essentially too low.
On swelling
Authors: Buchner E. H.
Published: September 2010

The existing theories of swelling are briefly discussed. A new conception of its mechanism is proposed.
Zur Ortsbestimmung der Deuteriumatome in Deuterierten Glutaminsäuren
Authors: Kögl F. , Klein A. J. , Erxleben H. , van Veersen G. J.
Published: September 2010

Die Mitteilung enthält eine vergleichende Studie über den Ort der Deuteriumatome in deuterierten Glutaminsäuren, die auf verschiedenen Wegen synthetisch oder durch enzymatische Umsetzungen in vivo gewonnen sind.
Dispersoid Analyses of Hevea Latex
Authors: Hessels J. H. E.
Published: September 2010

For the purpose of determining the weight distribution curve of the rubber particles in Hevea latex according to their diameter, two methods were employed, namely a photomicrographic dispersoid analysis and a sedimentation analysis. In addition to the fact, that the first method is very laborious, its precision doet not prove to be high mainly because a significant percentage of the particles is too small to be determined microscopically in the visible spectrum. Sedimentation analysis with the help of a modified pipette method according to Andreasen was found, however, to be very suitable for the purpose. By an accurate regulation of the viscosity, specific gravity and temperature of the suspension it became possible to determine the weight distribution curve of latex to a diameter of about 0.4 μ within a creaming time of 10 to 14 days, while the total percentage of still smaller particles was also determined at the same time. This method is accurate not too laborious and lends itself very well to series investigations.
The Raman spectra of the compounds CHCl2.CH2Cl, CCl3.CH2Cl, C2Cl6 and CHCl2.CCl2.CHCl2
Authors: Gerding H. , Haring H. G.
Published: September 2010

The Raman spectra of liquid CHCl2.CH2Cl, CCl3.CH2Cl (for the first time) and of molten C2Cl6 at ∼200° are given. Polarization measurements were performed for all of them and for liquid CHCl2.CCl2.CHCl2.

The characteristic “CH2” vibrations in CCl3.CH2Cl are determined. In CHCl2.CH2Cl, “CH‐” and “CH2‐” vibrations may be distinguished, the coupling between the different hydrogen vibrations (in particular valency vibrations) being of subordinate magnitude only.

CHCl2.CCl2.CHCl2 possesses symmetry C2v in all probability.

Some new lines for C2Cl6 have been found. This molecule probably possesses symmetry D3d in which the molecule halves perform torsional vibrations around the C‐C axis at the temperature of the experiments, which cause a number of otherwise forbidden lines to become weakly Raman active.
Researches on the alkoxy‐amino‐nitrobenzenes. Ia. Partial reduction of 1‐Alkoxy‐2,4‐dinitrobenzenes with sodium disulphide in aqueous suspension
Authors: Verkade P. E. , Meerburg W.
Published: September 2010

The partial reduction of 1‐alkoxy‐2,4‐dinitrobenzenes with sodium disulphide in aqueous suspension is described. It gives rise to a mixture of the 1‐alkoxy‐2‐amino‐4‐nitro and 1‐alkoxy‐2‐nitro‐4‐amino compound.
The decomposition of some alkyl acetates
Authors: Houtman J. P. W. , van Steenis J. , Heertjes P. M.
Published: September 2010

The decomposition at high temperatures over glass‐wool of the acetic acid esters of butanol‐1, butanol‐2, 2‐methylpropanol‐1, 2‐methylpropanol‐2, 2‐methylbutanol‐1, 3‐methylbutanol‐1 and hexadecanol‐1 to acetic acid and the corresponding alkene was investigated. It was found that glass‐wool is not the active catalyst for the reaction. In some cases a small amount of isomerism of the double bond could be detected. Some observations on the reaction mechanism are included.
The insecticidal constituents of pachyrrhizus erosus urban. I
Authors: Meijer Th. M.
Published: September 2010

A review of the literature concerning investigations, chemical as well as insecticidal of the seeds of Pachyrrhizus erosus Urban is given. The fatty‐oil content and the content of material that may be extracted with ether have been determined for a number of samples and recorded in a table. The oil extract varied from 20.0–22.9 per cent, the ether extract from 1.0–2.0 per cent. The latter has been found to be very toxic for caterpillars of the cabbage butterfly. Chemical investigation of the ether extract led to the isolation of several substances, one of which, called pachyrrhizone, had the composition C21H16O7, with a melting point of 248° C and a specific optical rotation in chloroform of − 95°. An oxime was prepared, with a melting point of 269–272°C. One OCH3 group was present. A dehydro compound C21H16O7 was formed by treatment with iodine and sodium acetate, ring‐fission probably taking place. A compound called pachyrrhizonic acid C21H16O11 was obtained by the action of alcoholic potash, a tentative formula for this derivative is given. On oxidation with potassium permanganate a substance C9H10O5, melting point 183–184° C. was formed, to which the constitution of 2‐methoxyhydroquinone‐4‐hydroxy acetic acid was given. The investigation is to be continued.
Untersuchungen über Indolderivate VIII. Einige vorläufige Versuche über den Einfluss des (Pseudo‐)‐Katalysators bei der Bildung von Indolderivaten aus Phenylalkylamino‐propanonen
Authors: Verkade P. E. , Lieste J. , Meerburg Frl. W.
Published: September 2010

Festgestellt wurde, dass die Bildung von Indolderivaten aus Phenylalkylaminopropanonen unter Einfluss von Zinkchlorid und von Salzsäure auf typisch verschiedene Weise verläuft. Letztere Substanz hat eine viel stärkere spaltende Wirkung auf das α‐Arylaminoketon als erstere und lässt dadurch die Bildung von Indolderivaten unter Umlagerung mehr oder weniger in den Vordergrund treten. Mit Zinkchlorid als (Pseudo‐)Katalysator tritt praktisch nur wahre Ringschliessung auf. Der Unterschied zwischen der Wirkungsweise beider (Pseudo‐)Katalysatoren liess sich für präparative Zwecke verwenden.
Δ5,6‐acetoxy‐3 β‐hydroxy‐17‐nor‐cholenic acid lactone, a by‐product of the cholesterol oxidation
Authors: Veer W. L. C. , Goldschmidt St.
Published: September 2010

The isolation of the semicarbazone C47H69O7N3, from a semicarbazone fraction of the cholesterol oxidation is described. This semicarbazone is a double compound between trans‐dehydroandrosterone acetate semicarbazone and a lactone C25H36O4, previously described by Miescher and Fischer. The structure of this lactone was examined and proved to be Δ5,6‐acetoxy‐3 β‐hydroxy‐17‐nor‐cholenic acid lactone.
Investigations on sterols: I. A new synthesis of 7‐dehydrocholesterol (provitamin D)
Authors: Buisman J. A. Keverling , Stevens W. , Vliet J. V. D.
Published: September 2010

A new synthesis of 7‐dehydrocholesterol (provitamin D3) from cholesterol is described, which gives a higher yield than the well known Windaus synthesis. The synthesis is carried out via a 7‐bromocholesteryl ester, from which hydrogen bromide is eliminated to give an ester of 7‐dehydrocholesterol.

Careful hydrolysis of the impure 7‐bromocholesteryl benzoate affords either 7‐α‐ or 7‐β‐hydroxycholesteryl‐3 benzoate depending on the reagent. The two epimeric 7‐bromocholesteryl benzoates are prepared from the hydroxy‐compounds by interaction with phosphorus tribromide; the two hydroxy‐compounds are regenerated by hydrolysis.
Note on the theory of ionic association
Authors: Broer L. J. F.
Published: September 2010

The derivation of the Fuoss distribution function for ion pairs in a strong electrolyte is discussed. An improvement of this function is proposed which is adapted to the calculation of the number of associated pairs. In a simple case the association is computed with the corrected and uncorrected functions and compared with the exact value obtained from the law of mass action.
Researches on heat of combustion V: Correction for heat exchange between calorimeter vessel and its surroundings
Authors: Coops J. , van Nes K.
Published: September 2010

In order to be able to calculate readily the so‐called “radiation” correction in calorimetric measurements, the jacket‐temperature must be kept constant and the contents of the calorimeter vessel must be stirred at a constant speed. This article describes a thermo‐regulator for this purpose, in which the fluctuations are not greater than 0.002°.

For every calorimeter used for accurate work, it is desirable to investigate beforehand whether the heat exchange between the vessel and the jacket satisfies Newton's equation. With the help of recent data it has been investigated how wide the air layer may be before convection occurs. This is necessary in order to obtain a system which satisfies Newton's equation.

Finally, various methods of approximation for calculating the “radiation” integral are discussed.
The ozonization of naphthalene and its homologues: (Remarks on a paper by J. P. Wibaut and J. van Dijk, “The ozonization of 2,3‐dimethylnaphthalene” etc.)
Authors: Kooyman E. C.
Published: September 2010

Some amplifying remarks are made on the paper by Wibaut and van Dijk concerning the ozonization of 2,3‐dimethylnaphthalene and 1,4‐dimethylnaphthalene.

It is shown that the experimental results may be interpreted in accordance with former conclusions regarding the bond structure of the naphthalene molecule, viz. that a double bond seems to be available at the α,β‐positions only.
Discussion of the structure of a few polychloro compounds with the help of raman effect data
Authors: Gerding H. , Rijnders G. W. A.
Published: September 2010

Some remarks are made concerning the structures of a heptachlorobutane and two pentachlorobutanes prepared by Prins and of a dodekachlorohexane of van der Linden.

The structures of two fractions obtained by distilling a mixture of cis‐ and trans‐tetrachloropropene‐1 are discussed with the help of Raman effect data and dielectric measurement results given in this paper. No definite conclusion could be drawn, although in particular the Raman results make it probable, that the higher boiling fraction agrees with the cis isomer. Isomers due to hindered rotation about the CC single bond are present for this isomer also.

The open chain compound C5Cl8 has the formula CCl2 = CCl. CCl = = CCl. CCl3 as was already made probable by Prins. Taking account of hindered rotation around the single bond, and stereoisomerism caused by one of the double bonds, a trans‐trans configuration seems by far the more probable one on steric grounds.

Liquid decachlorohexadiene C6Cl10 possesses ‐ according to the Raman data ‐ the structure CCl3. CCl = CCl. CCl = CCl. CCl3. The presence of two conjugated double bonds in this molecule is highly probable. The conversion of solid C6Cl10 ‐ CCl2=CCl. CCl2. CCl2. CCl = CCl2 according to Prins ‐ into liquid C6Cl10 would therefore be coupled with the displacement of two double bonds.
Researches on sulphanilamide, para‐amino‐benzoic acid and their derivatives. III: Ultraviolet absorption spectra and potentiometric titrations
Authors: Havinga E. , Veldstra H.
Published: September 2010

With the aim of providing more facts for the discussion of the mode of action of the sulphonamides and of p‐aminobenzoic acid, the ultraviolet absorption spectra are recorded for a number of sulphanilamide derivatives, p‐aminobenzoic acid and related compounds.

Moreover their electrochemical properties are determined by potentiometric titration.

The results obtained permit a more detailed discussion of the state of these molecules in neutral solution, of the differences between p‐aminobenzoic acid and its isomers and of those between sulphanilamide and its heterocyclic derivatives.

Furthermore the separate position of compounds like p‐aminomethylbenzoic acid and of p‐aminomethyl‐benzenesulphonamide (Marfanil) is clearly indicated.
The isomerization equilibria of the butanes, pentanes, hexanes and heptanes
Authors: van Eijk van Voorthuijsen J. J. B.
Published: September 2010

In continuation of the experiments described in a publication by Schuit and co‐workers we determined, partly re‐determined, the equilibrium positions of the isomerization reactions of the paraffin hydrocarbons of 4 to 7 carbon atoms.

In spite of the use of a very active AlCl3 catalyst the following hydrocarbons were not formed under the conditions applied:

C5: dimethylpropane (neopentane); C7: 2,2‐dimethylpentane (neoheptane); 3,3‐dimethylpentane and 3‐ethylpentane.

Conversely, neoheptane (the only one of those four hydrocarbons that was available) remained completely unattacked under the same conditions.

The results of our measurements were compared with experimental and thermodynamically calculated data from the literature. In the case of the butanes, pentanes and hexanes the agreement with the thermodynamic equilibrium position was moderate to good, in the case of the heptanes rather considerable deviations were found.
Dérivés des Nitrophénylsulfonyl‐Guanidines
Authors: Backer H. J. , Moed H. D.
Published: September 2010

La réaction des nitrobenzènesulfochlorures sur la guanidine engendre les mono‐nitrophénylsulfonyl‐guanidines. Comme produits secondaires, on obtient les bis‐nitrophénylsulfonyl‐guanidines, qu'on peut préparer également en introduisant un second groupe nitrophénylsulfonyle dans les composésmono. Ce dernier procédé offre la possibilité d'obtenir les composés‐bis mixtes, ayant deux groupes nitro en position différente. Les composés‐bis étant solubles dans les alcalis, les deux groupes nitrophénylsulfonyle doivent être liés à deux atomes d'azote différents.

Lorsqu'on fait agir les nitrobenzènesulfochlorures sur la diméthylguanidine asym. et sur la tétraméthylguanidine sym., on n'obtient que les produits mono‐nitrophénylsulfonyle; il n'y entre pas un second groupe substituant.

La réaction des nitrophénylsulfochlorures sur la p‐nitrophénylguanidine et sur la diphénylguanidine sym. donne naissance à plusieurs produits.
The calculation of maxima in vapour‐pressure curves
Authors: Korvezee A. E. , Dingemans P. , Dijkgraaf L. L.
Published: September 2010

A simple approximate relation is derived for the temperature of the maximum occurring in the vapour‐pressure lines of saturated solutions of a number of non‐volatile substances of high melting point in a volatile solvent. The derivation is analogous to that for saturated solutions of one dissolved substance.

This formula, although derived only for ideal mixtures, is found to give reasonably satisfactory results for a series of vapour‐pressure curves determined in this laboratory in non‐ideal systems.
Some 4.4′‐diformyl‐α,ω‐diphenoxyalkanes and their derivatives
Authors: Neish William J. P.
Published: September 2010

Some 4,4′‐diformyl‐α,ω‐diphenoxyalkanes have been prepared by reacting the sodium salt of p‐hydroxybenzaldehyde with α,ω‐dibromoalkanes. These compounds were oxidised by alkaline potassium permanganate solution to the corresponding α,ω‐diphenoxyalkane‐4,4′‐dicarboxylic acids. The diformyl compounds were reacted with malonic acid yielding acrylic acid derivatives which have the melting‐point characteristics of mesomorphic substances. Hippuric acid has been shown to condense readily with the diformyl products yielding mono‐ and bis‐azlactones.
Microdosage photometrique du chloralose en solution alcoolique: Note préliminaire
Authors: Delvenne J. , Barac G.
Published: September 2010

Nous décrivons une méthode de dosage du chloralose basée sur la réaction colorée résorcinosulfurique.
Action of cyclohexylamine on aromatic halogeno‐nitro‐compounds
Authors: Blanksma J. J. , Wilmink G. F.
Published: September 2010

The action of cyclohexylamine on 1‐chloro‐2‐nitrobenzene, 1‐chloro‐4‐nitrobenzene, 1‐chloro‐2,4‐dinitrobenzene, and 1‐chloro‐2,4,6‐trinitrobenzene has been investigated. The nitro‐cyclohexylaminobenzenes so found were nitrated and 2,4,6‐trinitrophenylcyclohexylnitramine, a colourless explosive product, similar to 2,4,6‐trinitrophenylmethylnitramine or the well‐known explosive, tetryl, was obtained.
The detection of small amounts of carbonate
Authors: van Dalen E. , de Vries G.
Published: September 2010

An apparatus design is described for testing for carbonates by means of baryta water, with which the sensitivity is improved to 1 μg in 0.05 ml and the certainty in judgement appreciably increased in comparison with the test by means of phenolphthaleine, by the removal of the disturbing action of the CO2 in the air.
The crystal structure of aluminium chloride
Authors: Ketelaar J. A. A. , MacGillavry C. H. , Renes P. A.
Published: September 2010

Aluminium chloride crystallizes in an ionic layer lattice. The dimensions of the monoclinic cell and the position of the chlorine atoms, given by Ketelaar in a previous investigation, are confirmed. The position of the Al‐atoms is different; instead of the ionic structure described in this paper, Ketelaar found a molecular lattice of “octahedral” molecules, fig. 1a. The structure appears to be in conflict with the result of the Raman investigation of solid AlCl3 by Gerding and Smit, which suggested a packing of “tetrahedral” molecules, fig. 1b.
Vapour‐liquid equilibria in ternary systems. IV. The system water‐ethanol‐trichloroethene
Authors: Reinders W. , de Minjer C. H.
Published: September 2010

The position of the ternary and of the three binary azeotropic points has been determined for the system water‐ethanol‐trichloroethene. The ternary point was found at: 6.1% water, 15.9% ethanol and 78.0% trichloroethene.

The procedure for dehydrating 95% ethanol by means of benzene has been compared with that in which trichloroethene is used in place of benzene.
Vapour‐liquid equilibria in ternary systems. VI. The system water‐acetone‐chloroform
Authors: Reinders W. , de Minjer C. H.
Published: September 2010

The heterogeneous equilibria between liquid and vapour phases in the system water‐acetone‐chloroform have been investigated at a pressure of 760 mm. It appears that a saddle point occurs in the two‐liquids area of this system and that in addition a minimum occurs in the liquid surface. The positions of these two points have been determined. The vapour phase corresponding to the minimum does not form a minimum in the vapour surface as a result ow which this vapour is not condensed on rectification as a separate fraction. This minimum gives rise to the unusual phenomenon that the boiling point of some ternary mixtures does not rise on continued rectification but falls.
Vaccenic acid
Authors: Groot E. H. , Kentie A. , Knol H. W.
Published: September 2010

A brief review of the earlier work on vaccenic acid is given. The preparation of this fatty acid, in an almost pure form, is discussed and the ultraviolet absorption spectrum is described.
On the structure of p‐aminophenyl‐sulphonylguanidine and bis‐(p‐aminophenyl‐sulphonyl)‐guanidine
Authors: Goldschmidt St. , Ruttink J.
Published: September 2010

The preparation and properties of p‐aminophenylsulphonylguanidine and of bis‐(p‐aminophenylsulphonyl)‐guanidine are described in this article.
An apparatus for the colour measurement of dyed textiles
Authors: Heertjes P. M. , van den Heuvel E. , Lotichius J.
Published: September 2010

Proceeding from the Keuffel & Esser Color Analyzer a photo‐electric apparatus was designed, which can render good service for the colour measurement of dyed textiles.

The reflection at one or more wave lengths is determined and taken as a colour coordinate when studying the relation between the quantity of dyestuff on the fibre and the resulting colour.
The colorimetric determination of nickel. As Ni(4) dimethylglyoxime
Authors: Haar K. Ter , Westerveld W.
Published: September 2010

A description is given of a colorimetric determination of nickel as Ni(4) dimethylglyoxime, but in contrast to the customary methods, use is made of persulphate as oxidizing agent. The influence of other metallic ions has been investigated too.

It appears that, of the elements investigated Ag must be removed, while the alkaline earth metals give a sulphate precipitate which can be removed by centrifuging. The determination of Ni in the presence of Mn, Fe, Cu and Co presents the greatest difficulties. In many cases we have succeeded finally in determining nickel in the presence of these elements without removing them. Thus it is possible to determine accurately 5% Ni and over in manganese, 0.25% and over in iron, 0.05% and over in copper and 0.05% and over in cobalt.

In general it has been established that the highest accuracy is obtained when full attention is paid to the following points:

the avoidence of ammonia

the regulation of the amount of dimethylglyoxime

the acidity of the solution.

If one of these points is not in order, the degree of accuracy becomes less. This is the case in the determination of Ni in the presence of cobalt, copper, in which case the presence of ammonia is a necessary condition for the formation of the colour.

It can be remarked that this method is extensively applied in our laboratory in the determination of Ni in chrome‐iron. Mo and W compounds.
Refractometric investigations on unbranched alkenes with a terminal double bond. The refraction equivalent of the >C  C< bond
Authors: Geldof H. , Wibaut J. P.
Published: September 2010

The preparation of the alkenes with a terminal double bond from C5to C10, C12, C16and C18inclusive in a high degree of purity is described. The refractive indices have been measured at 20° C and 25° C for 9 wavelengths and the densities measured at the same temperatures. After discussing the calculation of the refraction equivalent for the CH2group and the increment for the double bond according toEisenlohr, our experimental material has been used to calculate by the method of least squares, the refraction equivalents of the CH2group and the double bond for 9 wavelengths and the dispersion equivalents at 20° C and 25° C according to theLorentz‐LorenzandGladstone‐Daleformulae. The value for the terminal double bond [H2]1according to the method used byEykmanhas also been determined. In this way it has been possible to obtain accurate values for the refraction increment of the double bond, for the refraction equivalent of the CH2group and for the dispersion in the series of 1‐alkenes. The values we have obtained for the refraction equivalent of the double bond differ considerably from those ofEisenlohr, which are at present in general use.
Sur la Réactivité du Dibenzofuran et de Ses Isologues
Authors: Buu‐Hoï Ng. Ph. , Royer René
Published: September 2010

Dans ce travail, on examine le comportement du dibenzofuran vis‐à‐vis de quelques réactifs‐types: chlorures d acides gras, aromatiques ou hétérocycliques, brome libre, N‐bromosuccinimide. On compare ensuite la réactivité du dibenzofuran à celles de ses isologues tels que les carbazoles, le dibenzothiophène et le fluorène. Il est montré que le dibenzofuran possède une grande tendance à donner des dérivés 3,6‐disubstitués tout comme les carbazoles, mais sa réactivité est beaucoup moindre, quoique légèrement supérieure à celle du dibenzothiophène. Au cours de ces recherches, de nombreux corps nouveaux appartenant à la série du dibenzofuran, à celle du dibenzothiophène, et à celle du fluorène sont décrits; certains d'entre eux font l'objet d'études physiologiques (pouvoir oestrogène, par exemple).
The vapour pressure of aqueous solutions, saturated with respect to ammonium nitrate and sodium nitrate
Authors: Dingemans P. , Dijkgraaf L. L.
Published: September 2010

The vapour pressure of the four‐phase equilibrium: water vapour‐saturated solution‐solid NH4NO3‐solid NaNO3 has been measured from 10° C to the end of this line, i e. the eutectic of the binary system NH4NO3)‐NaNO3.

We found this eutectic to lie at 121.1 ± 0.1° C and at a composition of 78.2 percents by weight of NH4NO3, and 21.8 percents by weight of NaNO3.

The vapour pressure line has a maximum at 94.0° C and a pressure of 82.4 mm Hg.

Previously deduced formulae for the calculation of maxima in vapour pressure lines and for the calculation of metastable eutectics, are found in this case also to give good agreement with the experimental results.
Researches on the alkoxy‐amino‐nitrobenzenes: V.) Fission of the methyl group in the nitration of 1‐alkyloxy‐2‐(p‐toluenesulphonyl)methylaminobenzenes with dilute nitric acid
Authors: Bosma G. S. K. , Verkade P. E.
Published: September 2010

Nitraiton of 1‐alkyloxy‐2‐(p‐toluenesulphonyl)methylaminobenzenes with 10% nitric acid at 80‐85° leads to the formation of 1‐alkyloxy‐2‐(p‐toluenesulphonyl)amino‐5‐nitrobenzenes. Under these conditions the methyl group attached to nitrogen is split off.
Carbonyl‐substituted naphthoquinones: Part II. Ketones of the type C10H7O2COCH2R
Authors: Spruit C. J. P.
Published: September 2010

In a previous publication

C. J. P. Spruit, Rec. trav. chim. 66, 655 (1947).

) we dealt with the preparation and properties of a number of derivatives of naphthyl‐2‐methylketone

The name ‐ acetyl ‐ for the side chain, adopted in Part I for the sake of brevity, is abandoned for the substitution products. It is felt that the present nomenclature is not entirely satisfactory, especially for the quinones.

, substituted in various positions of the nucleus. This paper describes some compounds, derived from 1,4‐dihydroxynaphthyl‐2‐methylketone and 1,2‐dihydroxynaphthyl‐3‐methylketone by substitution in the methyl group.

Although it has been found possible in some cases, to introduce the grouping ‐COCH2R directly into derivatives of naphthalene, by far the most convenient way has been found in the photochemical bromination of 1,4‐dihydroxynaphthyl‐2‐methylketone. The bromine atom in the resulting 1,4‐dihydroxynaphthyl‐2‐bromomethylketone is reactive, and may be replaced by other groups.
The structure of the formylation (OXO) products obtained from olefines and watergas
Authors: Keulemans A. I. M. , Kwantes A. , van Bavel Th.
Published: September 2010

A number of pure olefines with up to 8 C atoms was subjected to formylation, a process by which CO and H2 are added to the olefine followed by hydrogenation of the aldehydes obtained to the corresponding alcohols. The structure of the alcohols was determined by converting them by careful dehydration and hydrogenation into the corresponding paraffins. The paraffins were analysed by analytical rectification and determination of physical constants. From the results a number of rules are derived, which make it possible to predict the structure of the alcohols to be obtained from a given olefine. The formylation reaction presents in many cases a convenient way of synthesizing new alcohols and hydrocarbons, some of which are described.
The chemistry of 2‐aminofluorene: 1. Reaction of 2‐aminofluorene with pyruvic acid
Authors: Neish W. J. P.
Published: September 2010

2‐Aminofluorene condenses with pyruvic acid to yield the cinchoninic acid, 6‐methyl‐2,3‐(fluoreno)2′,1′‐pyridine‐4‐carboxylic acid. The compound is readily decarboxylated to 6‐methyl‐2,3‐(fluoreno‐2′1′)‐pyridine]. The possible significance of the cinchoninic acid structure for chemical carcinogenesis is discussed.
On the reaction between 5‐aminoacenaphthene and pyruvic acid
Authors: Neish W. J. P.
Published: September 2010

6‐Methyl‐[acenaphtheno‐5′,4′‐2,3‐pyridine]‐4‐carboxylic acid has been prepared by reacting 5‐aminoacenaphthene with pyruvic acid in ethanol. The compound was decarboxylated by soda‐lime to give 6‐methyl‐[acenaphtheno‐5′,4′‐2,3‐pyridine].
The reactivity of bromine atoms in brominated pyridines. The preparation of 3‐acetylamino‐5‐ethoxypyridine from 3,5‐dibromopyridine
Authors: den Hertog H. J. , Falter A. W. M. , van der Linde A.
Published: September 2010

3‐Acetylamino‐5‐ethoxypyridine was prepared by converting 3,5‐dibromopyridine with sodium ethylate into 3‐bromo‐5‐ethoxypyridine, allowing this substance to interact with ammonia and acetylating the aminoethoxypyridine thus formed with acetic anhydride.
The reactivity of bromine atoms in brominated pyridines. The action of sodium methylate on 2,4,6‐tribromopyridine
Authors: den Hertog H. J.
Published: September 2010

The action of sodium methylate on 2,4,6‐tribromopyridine is described. The bromine atoms are very easily replaced by methoxyl groups, in the order 4, 2, 6. A proof of structure is given for each of the substances formed.
Investigations on glycidyl ethers, I. The synthesis of aromatic bisglycidyl ethers
Authors: Werner E. G. G. , Farenhorst E.
Published: September 2010

The synthesis of aromatic bisglycidyl ethers from epichlorohydrin and bivalent phenols under the influence of alkali has been investigated. Hydroquinone bisglycidyl ether has been separated into two diastereoisomers.
Condensation reactions of ketones with hydroxymaleic anhydride: Transformation of the condensation products into α,β‐unsaturated aldehydes
Authors: van Dorp D. A. , Arens J. F.
Published: September 2010

Ketones can be condensed with hydroxymaleic anhydride under the influence of hydrogen chloride to give acids of the type

magnified image

The elimination of two molecules of carbon dioxide gives rise to aldehydes

magnified image

In general the method seems unsuitable, however, for the preparation of large quantities of these aldehydes.
Rate of Dissolution of Solid Substances Part I. Rate of mass transfer in granular beds (Physical dissolution)
Authors: van Krevelen D. W. , Krekels J. T. C.
Published: September 2010

Rate of mass transfer in granular beds has been studied by determining the rate of dissolution of benzoic acid in water and aqueous glycerol solutions and of sulphur in benzene. For liquid‐continuous flow and film‐like flow, mass transfer coefficients could be correlated by dimensionless equations
Alkylation of isopentane with isopentene in the presence of concentrated sulphuric acid
Authors: van Steenis J. , Waterman H. I.
Published: September 2010

Alkylation of isopentene with isopentane and sulphuric acid can be accomplished in two minutes reaction time, provided that the reacting substances are emulsified during the reaction.

The most favourable ratio of the reacting substances (volumes) is about 5 of isoparaffin; 2 1/2 of sulphuric acid; 1 of olefin. If the reaction conditions are favourable to the formation of polymer hydrocarbons from the olefin (bad mixing) a long reaction time is required to obtain a “good alkylate”.

The formation of products with an anomalous number of carbon atoms proceeds simultaneously with the formation of pure alkylate (C10). With isopentene the formation of polymer‐sulphuric acid esters is the first step in the formation of alkylate.
A useful variant of the two‐line method for calibration of photographic emulsions
Authors: Schmidt R.
Published: September 2010

Fundamentals of the two‐line method of emulsion calibration, in which the characteristic curve is derived from densities of two spectrum lines of constant relative intensity, photographed at different densitiy levels, are discussed.

It has been found, that the principles of this method can be applied to the presentation of data obtained by any method of calibration, which is based on an intensity pattern following a geometrical series. The scope of the method is considerably widened by substitution of densities (\documentclass{article}\pagestyle{empty}\begin{document}$ \log \,\frac{{{\rm A}_{\rm o} }}{{\rm A}} $\end{document}) by densities transformed according to Seidel (\documentclass{article}\pagestyle{empty}\begin{document}$ \log \,(\frac{{{\rm A}_{\rm o} }}{{\rm A}} - 1) $\end{document}).