bluuebunny/crossref_metadata_2025_split huggingface dataset:
The raman spectrum of sulphur in the liquid viscous state
Authors: Gerding H. , Westrik R. 
Published: September 2010

AbstractThe Raman spectra of solutions of sulphur in carbon disulphide at 18°, of sulphur in molten naphthalene at 110°, of liquid sulphur at 120° and of viscous liquid sulphur at 190° have been determined. In both solutions and in the liquid at 120° sulphur is mainly present as S8. New frequency shifts are found for the liquid at 190°, proving that transformations in the liquid have taken place. It is not possible however to draw a definite conclusion about the molecular structure of Sμ Probably it consists of open chains of sulphur atoms as K. H. Meyer assumes, coupled with each other to a certain extent, so that a quasi‐crystalline structure of high viscosity occurs. The presence of a low vibrational frequency in the Raman spectrum of the liquid at 190° may be explained in this way.
Über die Anomale Rotationsdispersion der l‐Pyrrolidon‐5‐Carbonsäure‐2 und ihres Äthylesters
Authors: Froentjes W. 
Published: September 2010

AbstractDie Rotationsdispersionskurven der Pyrrolidoncarbonsäure (im folgenden mit Prolon bezeichnet) und ihres äthylesters wurden in Abhängigkeit von Lösungsmittel, Konzentration und Temperatur gemessen. Nimmt man als Kriterium für den Verlauf der Dispersion die graphische Analyse nach Biot‐Lowry, so zeigt sich, dass hier Anomalien auftreten.Die für eine Erklärung dieses Verhaltens in Betracht kommenden Hypothesen werden diskutiert. Es stellt sich dabei heraus, dass durch die Annahme eines Gleichgewichtes zwischen Molekülen mit innermolekularer Wasserstoffbrücke (zwischen dem N‐Atom und einem O‐Atom der Carboxylgruppe) und Molekülen ohne diese Wasserstoffbrücke, die Anomalie in der Rotationsdispersion und das Verhalten gegen Verdünnung und Lösungsmittel erklärt werden können. Daneben muss in einigen Fällen noch eine Assoziation berücksichtigt werden. Aus einem Vergleich der Elektronenstrukturformeln und möglichen Resonanzen in den Molekülen des Prolons, Prolins und 4‐Hydroxyprolins können die charakteristischen Unterschiede in Rotation, Komplexbildung und Acidität zwischen diesen Säuren erklärt werden.
Eine Methode zur Berechnung der Polarisierbarkeit und des Radius von Molekülen und Ionen
Authors: Böttcher C. J. F. 
Published: September 2010

AbstractWith the aid of a new formula for the internal field a method is developed for computing the mean polarisability and the mean radius of molecules and ions from measurements of the density and the dielectric constant (or, alternatively, the index of refraction) of liquids.As examples, the radii and the polarisabilities of the CCl4‐molecule and of the I‐, CL−, Cs+ and Rb+ ions are calculated. The values obtained for the radii of the ions are in good agreement with those of Pauling and Goldschmidt.
Pyrazolenines and their rearrangement to form pyrazoles, I* ): (Pyrazole and pyrazoline derivatives, III)
Authors: van Alphen J. 
Published: September 2010

AbstractBy the addition of diphenyldiazomethane to the methyl esters of acetylene dicarbonic acid, of phenyl propiolic acid and of propiolic acid, pyrazolenines are formed, which, under different circumstances and with a migration of several groups, undergo a rearrangement into pyrazoles.
Pyrazolines and their rearrangement to form pyrazoles. II. (Pyrazole and pyrazoline derivatives, IV)
Authors: van Alphen J. 
Published: September 2010

AbstractUpon the addition of diphenylenediazomethane to the methyl esters of acetylene dicarbonic acid, of phenylpropiolic acid and of propiolic acid, pyrazolenines are formed which, under different circumstances and with the migration of several groups, undergo rearrangement to give pyrazoles.
Sur la Structure de la Pelletiérine
Authors: Beets M. G. J. 
Published: September 2010

AbstractLe mémoire discute les possibilités de mésomérie et de tautomérie de la structure attribuée par H e s s à la pelletiérine.On a obtenu une première indication pour le fait que dans la pelletiérine une structure bicyclique peut jouer un rǒle.
Untersuchungen über Pflanzliche Wuchsstoffe. VII. Über Struktur und Wirkungsmechanismus der Pflanzlichen Wuchs‐ und Hemmstoffe
Authors: Veldstra H. , Havinga E. 
Published: September 2010

The view of the mechanism of the action of plant growth substances developed elsewhere has led to the assumption that growth substances and inhibitors in plants may be closely related1). The results of some recent investigations10) 11), which in our opinion support this view, are discussed, and in the case of cis‐cinnamic acid coumarin (lactone of o‐oxy(cis)cinnamic acid) such a structurally related pair of growth substance and inhibitor is indicated.In the pea test, inhibitor (coumarin) and growth substance (naphthalene acetic acid) prove to be antagonists, while such an influence cannot be established in the blastokolin test. A number of compounds with the structure of inhibitors (unsaturated lactones) are examined in the blastokolin test. Furthermore the importance of these investigations for the natural auxins is outlined. The formation of unsaturated δ‐lactones, being possible in that case, does really occur in the photo‐inactivation of auxin‐a‐lactone (conversion into lumi‐auxone). On account of this the hypothesis is developed that lumi‐auxone (or a closely related compound) may perform the function of an inhibitor.Finally a number of facts from botanical investigations are summarized, which point to the close relationship between growth substance and inhibitor and which, moreover, support the view of the function of lumi‐auxone (or related compound)
Die Strömungsdoppelbrechung in Lösungen Makromolekularer Substanzen
Authors: Hermans J. J. 
Published: September 2010

AbstractThe 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

AbstractIn 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

AbstractPour 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

AbstractA 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.
Untersuchungen über Pilzfarbstoffe XV. ): Über Phomazarin II
Authors: Kögl F. , Quackenbush F. W. 
Published: September 2010

AbstractAuf 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

AbstractAluminium 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 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

Abstract2‐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

AbstractPoursuivant 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

AbstractEs 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

AbstractDifferent 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

AbstractDans 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.
Action des trois nitrobenzènesulfochlorures sur la guanidine
Authors: Backer H. J. , Moed H. D. 
Published: September 2010

AbstractL'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 Raman spectrum of hexachlorocyclopentadiene C5Cl6
Authors: Gerding H. , Prins H. J. , van Brederode H. 
Published: September 2010

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractBaudetH. 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.
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

AbstractThe 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

AbstractAfter 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

AbstractThe 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

AbstractIt 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.
Zur Ortsbestimmung der Deuteriumatome in Deuterierten Glutaminsäuren
Authors: Kögl F. , Klein A. J. , Erxleben H. , van Veersen G. J. 
Published: September 2010

AbstractDie 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

AbstractFor 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

AbstractThe 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

AbstractThe 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.