bluuebunny/crossref_metadata_2025_split huggingface dataset:
Light pressure and photophoresis in colloidal solutions
Authors: Gribnau F. B. , Krom C. J. , Kruyt H. R. 
Published: September 2010

AbstractFrom the colloid chemical standpoint it is of interest with regard to light pressure that (a) the actual light pressure of the visible spectrum cannot be detected in colloidal solutions with the means available at present, (b) the results of the researches of Ehrenhaft and his co‐workers give but little information regarding the true light pressure, (c) the radiation of the nearest infra red can produce characteristic heat effects in colloidal solutions (such effects are usually grouped under the name of radiometer action), (d) the photophoresis effect observed by Barkas in sols is to be attributed to such a radiometer effect, (e) the transparency of water to the nearest infra red is frequently incorrectly left out of account, (f) in rendering the Brownian movement visible account must be taken of a possible movement caused by a radiometer effect, (g) in carrying out settling experiments, i. e. determination of the particle size by the sedimentation method using Stokes' law, attention must be paid to the influence of heat effects.
Ultra‐Violet absorption spectra of pyridine and pyridine derivatives
Authors: Spiers C. W. F. , Wibaut J. P. 
Published: September 2010

AbstractThe ultra‐violet absorption spectra of pyridine and 27 of its derivatives have been quantitatively measured. The possible errors have been calculated in every case. Some general remarks concerning the data and their interpretation are given.The pyridine derivatives investigated comprise six mono‐ and nine dihalogenated pyridines, the three mono amino‐pyridines, three amino‐halogeno‐pyridines, three dipyridyls, two dipyridylamines and a tripyridylamine.
Über β.Tritylierte Glycerolderivate
Authors: Verkade P. E. , van der Lee J. , Meerburg W. 
Published: September 2010

AbstractDie Bereitung von α Stearyl‐βγ. ditritylglycerol und von Tritritylglycerol wird beschrieben. Diese leichte Bildung von β.tritylierten Glycerolderivaten beweist von neuem, dass Tritylchlorid keineswegs ein spezifisches Reagens auf in einer Polyhydroxylverbindung vorhandene primäre Hydroxylgruppen ist. Vorgefasste Meinungen über die Konstitution eines ‐ sei es für synthetische Zwecke, sei es im Laufe einer Konstitutionsbestimmung hergestellten ‐ Tritylderivates einer Polyhydroxylverbindung sind daher vom Übel. In solchen Fällen wird man stets einen Beweis für die Konstitution dieses Stoffes erbringen müssen.
1,2‐Disélénacyclopentanes
Authors: Backer H. J. , Winter H. J. 
Published: September 2010

AbstractL'action du séléniure (et du diséléniure) potassique sur le 1,3‐dibromo‐2‐méthyl‐2‐phénylpropane donne, comme produit secondaire, le 4‐méthyl‐4‐phényl‐1,2‐disélénacyclopentane (voir la formule).On Prépare composé analogue aux dépens du 1,3‐dibromo‐2,2‐diméthylpropane par l'inter‐médiaire du bis‐sélénacyanure. L'anneau di‐sélénacyclopentane s'ouvre par l'oxydation qui conduit à un acide diséléninique.
A system of colloid phenomena
Authors: Hamaker H. C. 
Published: September 2010

AbstractColloid experiments are frequently interpreted on the assumption that attractive and repulsive forces are acting between the particles. In the paper below the consequences of this assumption are analysed from a theoretical point of view. It is found that the phenomena which may arise must logically be divided into two classes. These two classes show a very striking resemblance with the phenomena observed in lyophobic and lyophylic colloids respectively. It is also easily seen that the two classes of phenomena are not definitely separated, but that intermediate cases may exist. This is again in close agreement with the result of observation.Strictly, however, the therms “lyophobic” and “lyophylic” do not apply to our classes of phenomena; instead of this a distinction between “reversible” and “irreversible” phenomena is proposed and it is maintained that, by combining this classification with the common distinction between lyophobic and lyophylic colloids, a more satisfactory system of colloids and colloid phenomena is obtained.
The amorphous part of starch in fresh bread, and in fresh pastes and solutions of starch: (preliminary publication)
Authors: Katz J. R. 
Published: September 2010

AbstractThe V‐pattern of starch is difficult to understand. It is the x‐ray pattern of starch in fresh bread; and it is the x‐ray pattern of starch pastes and of starch solutions, after dehydration with alcohol.A real explanation of this x‐ray pattern cannot yet be given. But a series of facts found since 1930 makes another interpretation more probable than the one published then. It now seems most likely to be the superimposition of two patterns: an amorphous pattern of starch and a purely crystalline V‐pattern. But the old explanation still remains a possibility. When the new explanation is accepted, the change in the starch during the staling of bread is to be explained as the crystallization of the amorphous part of the swollen granules to a crystalline substance with a B‐pattern.And, on this basis, the micels in dilute fresh starch pastes and in dilute fresh starch solutions are to be considered as being chiefly amorphous. In very concentrated pastes and solutions they may be partly crystalline (with V‐pattern).
Some remarks on the complexity of the solid state of sulphur trioxide and other substances
Authors: Gerding H. , Gerding‐Kroon R. 
Published: September 2010

AbstractPhenomena of polymerisation, mainly studied for such organic substances as formaldehyde and styrene, are also present with sulphur trioxide and other inorganic substances and with a number of elements.They are responsible for several cases of allotropy of the solid state.
The determination of aneurin (= vitamin B1) in urine by the thiochrome reaction
Authors: Westenbrink H. G. K. , Goudsmit J. 
Published: September 2010

AbstractA chemical method, based on the thiochrome reaction, for the determination of aneurin in urine is described and discussed. The authors consider the accuracy of their method sufficient for most physiological, hygienic and clinical purposes.
The bromination of bromo‐, chloro‐ and fluorobenzenes in the gas phase; the effect of the temperature and catalyst on the substitution‐type
Authors: van Loon M. , Wibaut J. P. 
Published: September 2010

AbstractWith the aid of an improved and automatically working bromination apparatus, we have closely examined the bromination of bromobenzene, chlorobenzene and fluorobenzene in the gas phase.All the three halogenobenzenes investigated, show a change from the ortho‐para‐ to the meta‐substitution type at about 400‐450° in brominations with artificial graphite as contact substance. With bromobenzene the relative quantities of Ortho‐, meta‐ and para‐dibromobenzenes obtained were accurately determined at various reaction temperatures. The effect of temperature on the ratio in which the isomers are produced cannot be explained by the existing theories of substitution.The reaction took a completely different course in brominations with ferric bromide as a catalyst. Under these conditions, the reaction velocity is so high that the reaction can be investigated from 200°. With all three halogenobenzenes, the para‐ortho‐substitution type persists throughout the whole region of 200‐500°. Similar results were obtained with copper bromide as a catalyst. The theoretical views of Scheffer on the relationship between the reaction temperature and the ratio of the isomers so obtained, in substitutions in the benzene nucleus, which so far has only been tested experimentally over relatively small ranges of temperature, could now be tested over the range of 200‐450° with the data obtained in the bromination of bromobenzene with iron bromide as a catalyst. In this catalytic bromination, the agreement between the values found experimentally and those calculated from Scheffer's formula was excellent.According to the investigations of Holleman and his co‐workers the type of a disubstitution reaction (ortho‐para or meta substitution) is determined by the nature of the substituent already present. From our investigations it appears that in the case of Cl, Br or F atoms, which have so far been considered as typical ortho‐para directing atoms, the nature of the atom already in the benzene nucleus is not the sole factor determining the type of substitution. It depends on the temperature at which the reaction is carried out and the nature of the catalyst used, whether the reaction belongs to the ortho‐para type or the meta type.
Die Dampfspannung von gesättigten wässerigen Lösungen der Dihydroxybenzene
Authors: Dingemans P. 
Published: September 2010

AbstractBei der Durchsicht der Literatur fällt auf, dass die Dampfspannungen von gesättigten wässerigen Lösungen sowohl von anorganischen Salzen als auch von organischen Stoffen meistens nur über einen kleinen Temperaturbereich hin gemessen worden sind. Nur für die Systeme H2O‐AgNO3 1) und H2O‐NH4NO32) wurde die p‐T‐Linie der gesättigten Lösungen bis an den Schmelzpunkt der Salze bestimmt.
Hier werden jetzt die Resultate von, nach einer statischen Methode ausgeführten, Dampfspannungsmessungen von gesättigten wässerigen Lösungen von Resorcinol, von Pyrocatechol und von Chinol gegeben, von 15° C an und für die beiden ersteren Stoffe bis zum Schmelzpunkt des gelösten Stoffes.Ebenfalls wurden die Dampfspannungen von wässerigen Lösungen, gesättigt an einem dieser Stoffe, von 15° C an bis zu der eutektischen Temperatur der beiden gelösten Stoffe gemessen. Diese Eutektika wurden erneut bestimmt und für das System Pyrocatechol‐Resorcinol auch die gesamte Schmelzlinie. Dabei wurden bedeutende Unterschiede gegenüber den in der Literatur
H. W. Bakhuis Roozeboom, Verslag. Akad. Wetenschappen Amsterdam 10, 350 (1901)
E. Jänecke und E. Rahlfs, Z. anorg. allgem. Chem. 192, 237 1930
Sur L'Acide α‐Naphtylacétique
Authors: Olivier S. C. J. , Wit J. 
Published: September 2010

AbstractOn a amélioré la manière de préparer l'acide 1‐naphtylacétique, substance acrivant la croissance des végétaux. Pour le composé à l'état pur, on a déterminé un point de fusion de 135°‐135°.5, tandis qu'on trouve dans la littérature des chiffres variant de 106° à 132°.
Nitration and halogenation of 1 : 2‐bis‐(phenylamino)‐ethane and its derivatives. II
Authors: Schouten A. E. 
Published: September 2010

AbstractThis communication deals with a continuation of work described in the previous paper on this topic2). Some halogenonitro‐derivatives of 1:2‐bis‐(phenylamino)‐ethane with the halogen atom in themeta‐position are first described along with their nitration to explosive nitramines. The bromination and chlorination of 1:2‐bis‐(phenylamino)‐ethane and some of its derivatives are then discussed. The nitration of the acetyl compounds of 1:2‐bis‐(phenylamino) ‐ethane and its derivatives leads to the formulation of some rules on substitution. Finally, the nitration of N.N'diphenylpiperazine and its derivatives is dealt with, the occurrence of ring opening pointing to a striking analogy with van Romburgh's nitration of dimethylaniline.
The cohesive energy of liquid mixtures I
Authors: Staverman A. J. 
Published: September 2010

AbstractIt is shown that in computing the cohesive energy of a mixture it is possible to allow for the different sizes and shapes of the molecules by introducing an interaction constant. This constant is calculated for some molecules from the work of Hirobe; the calculation gives constant values for molecules of small polarity; for strongly polar molecules the theory will be given in a later paper.
The structure of aliphatic compounds: the walden inversion
Authors: Taylor William 
Published: September 2010

AbstractFrom kinetic measurements of the reactions of Me, Et, Pr β and Bu γ, phenyl ethers, acetates, alcohols (with hydrogen bromide) and bromides (with aqueous alcohol) Bu γ compounds are found to react very much more rapidly than the others. The suggestion is made that in primary and secondary aliphatic compounds. AlkX, X is bound partially by α‐hydrogen. This would support theories of Polanyi and others to explain the Walden Inversion as shown by the relative reactivities of the corresponding alkyl halides with anions.
The reduction of unsaturated ketones
Authors: Dippy J. Frederick J. , Lewis Reginald H. 
Published: September 2010

Abstract
Adequate details for the preparation of a number of unsaturated ketones (including substituted benzylidene acetophenones) are described.
Reduction of these unsaturated ketones by various chemical agencies has been studied.
Conversion to saturated ketones is effected by sodium amalgam in acetic acid. This method of obtaining such compounds is particularly useful since the necessary unsaturated ketones are derived in good yield by condensation of simple aldehydes and ketones.
Diketone secondary products in this mode of reduction are now shown to arise only at elevated temperatures.
The presence of chloro or nitro substituent inhibits reduction.
Generalisations made by Harries on the sodium amalgam reduction are criticised.
The Clemmensen reduction applies smoothly to benzylidene acetone yielding n‐propyl benzene.
The oxidation velocities of some alkenes with peracetic acid
Authors: Böeseken J. , Stuurman J. 
Published: September 2010

AbstractThe reactions of a number of alkenes and cyclenes with peracetic acid has been investigated in acetic acid solution, usually at various temperatures, in order to collect data on the E and B values of the Arrhenius equation:\documentclass{article}\pagestyle{empty}\begin{document}$$ \log \;k = \sim \frac{E} {{2.303\;RT}} + B. $$\end{document}It appeared that the reaction constant increases considerably as the hydrogen atoms on the unsaturated carbon atoms are replaced by alkyl groups, and this was chiefly to be ascribed to the fall in the E values. The B values also fall in the case of the cyclic compounds, in which one would expect some tension on steric considerations.
Sulfones Insaturées. I. Préparation et Constitution des Sulfones Investigées. Tautomérie des Sulfones
Authors: de Roy Van Zuydewijn E. 
Published: September 2010

AbstractLe but initial de mes recherches sur l'influence du groupe SO2sur la liaison double était exclusivement l'application de la méthode à l'acide borique de Böeseken aux diols eis‐ et trans‐ des sulfones cycliques, dérivées des butadiènes. Il va sans dire que la détermination de la constitution des sulfones insaturées devait précéder la préparation de ces diols, qui pouvait être exécutée autant par oxydation avec l'acide peracétique ou du KMnO4ou OsO4que par saponification du dibromure.De l'une des sulfones investigées, celle de l'isoprène, EigenbergerEigenberger, J. prakt. Chem. (2) 127, 307 (1930); 129, 312; 131, 289 (1931)) a décrit une isomérisation qu'il expliquait en admettant une transformation cis‐trans. En étudiant ce réarrangement de plus près, je constatai toutefois que l'interprétation d'Eigenberger était incorrecte, et qu'il s'agit ici d'un cas de tautoméric.Après que cette partie de mes recherches fut virtuellement terminée, il parut une publication de StratingJ. Strating, Thèse Groningue 1934), dans laquelle celui‐ci décrivait entre autres la détermination de la constitution d'un des composés étudiés par moi (la sulfone cyclique de diméthylbutadiène) et de quelques produits de son oxydation. Ici Strating signalait indépendamment de nous, que l'interprétation d'Eigenberger concernant l'isomération de la sulfone d'isoprène était intenable et montrait qu'il s'agit d'un changement de position de la double liaison. Les méthodes de Strating diffèrent pourtant assez de celles appliquées par moi; quant à l'isomérisation mentionnée plus haut, les résultats de mes recherches m'obligent à être d'un autre avis sur le mécanisme que celui proposé par Strating.En préparant les diols cis et trans susdits, j'observai que le groupe SO2rend l'attaque de la double liaison par des oxydants beaucoup plus difficile que dans le cas de la plupart des substances insaturées.Pour me faire une idée plus claire du caractère et de la grandeur de cette influence, j'essayai de mesurer la vitesse d'oxydation des sulfones insaturées à l'aide de l'acide peracétique. Ces mesures n'ont pourtant pas conduit au résultat attendu, parce qu'il fut constaté que la plupart des observations ne pouvaient être reproduites.
Untersuchungen ueber Pyrrolderivate 2. Mitteilung
Authors: Rinkes I. J. 
Published: September 2010

AbstractDie Ergebnisse der Substitution in den Pyrrolkern wurden näher durch Einführung einer zweiten Nitrogruppe in 2‐Acetyl‐4‐nitropyrrol, 2‐Acetyl‐5‐Nitropyrrol und 5‐Nitro‐2‐pyrrolcarbonsäure Methylester studiert.Es ergab sich, dass in allen Fällen Produkte entstanden, die auf Grund der Substitutionstheorie erwartet wurden.Die Methode zur Darstellung des 2‐5‐Pyrroldicarbonsäuremethylesters wurde verbessert.
Some derivatives of glucamine and galactamine
Authors: den Otter H. P. 
Published: September 2010

Abstract
Aniline was obtained in place of the desired N(2.3.4.5.6‐pentahydroxyhexyl)‐N‐(phenyl)‐amine on reduction of glucose‐anilide with aluminium amalgam or with Pd and hydrogen.
Reduction of glucosoxime with 3% sodium amalgam afforded glucamine, which could then be combined with 1‐choro‐2.4‐dinitrobenzene, picryl chloride, 1‐chloro‐2.4‐dinitronaphthalene and 1.3‐dichloro‐4.6‐dinitro‐benzene to give N(2.4‐dinitrophenyl)‐glucamine, N(2.4.6‐trinitrophenyl)‐glucamine, N(2.4‐dinitronaphthyl)‐glucamine and N(3‐chloro‐4.6‐dinitro‐phenyl)‐glucamine.
Galactosoxime can also be reduced with 3% sodium amalgam to give galactamine, which can be condensed with the compounds given in (2) to give N(2.4‐dinitrophenyl)‐galactamine, N(2.4.6‐trinitrophenyl)‐galactamine, N(2.4‐dinitronaphthyl)‐galactamine and N(3‐chloro‐4.6‐dinitrophenyl)‐galactamine.
Untersuchungen ueber Pyrrolderivate. 3. Mitteilung
Authors: Rinkes I. J. 
Published: September 2010

AbstractDie β‐Pyrrolcarbonsäure wird in der Literatur wiederholt beschrieben, aber in einer Abhandlung von Neisser (s.u.) gezeigt, dass sämtliche Bereitungsmethoden nur eine Modifikation der α‐Säure lieferten. Es gelang mir, mit Hilfe einer durchsichtigen Synthese die β‐Säure darzustellen und die Verschiedenheit von der α‐Säure zu erweisen.
Flame ranges and explosion regions
Authors: van Deventer A. M. 
Published: September 2010

AbstractFour ternary systems were investigated viz CH3ClairCCl2F2, C2H5ClairCCl2F2, C4H10airCCl2F2 and C4H10airC2H5Cl. In each system the lengths were determined over which the flame phenomenon was propagated in the mixtures through the explosion tube in the neighbourhood of the explosion limit.The limit curves were constructed and discussed.
On the composition and the crystallography of autunite and the meta‐autunites
Authors: Beintema J. 
Published: September 2010

AbstractThe optical behaviour of artificial autunite crystals was studied in connection with its water content. The autunite was shown to be transformed into meta‐autunite‐I on loosing water. The crystal structure of both compounds was studied by means of X‐rays. The remarkable properties of the mineral, namely its varying water content and the base exchange are associated with the crystal structure. By studying the corresponding Ba‐compound it is concluded that the cations in the meta‐autunite‐I probably do not occupy a fixed position. Because of their great mobility it is permissible to consider them as “vagabond ions”.
Synthese von Cyclopentenonen
Authors: Rinkes I. J. 
Published: September 2010

AbstractIm Dezember‐Heft der Helv. Chim. Acta erscheint eine Abhandlung von Plattner und St. Pfau: Transformations d'acides aliphatiques non saturés en cyclopenténones. Es gelang mir, ausgehend von Cyclopentanon, diese Ketone zu synthetisieren.
Symmetrical secondary diamines derived from 1:2‐diaminoethane
Authors: Rameau J. TH. L. B. 
Published: September 2010

AbstractSymmetrical 1:2‐disubstituted diamines derived from 1:2‐diaminoethane, have been prepared by condensing the latter with the appropriate aldehyde and reducing the Schiffs base so formed. The di‐secondary 1:2‐diamines, so obtained, were more closely investigated. With aldehydes, for example, they form 1:2: 3‐substituted tetrahydroimidazoles.
Ueber das Toxoflavin, ein Isomeres von I‐Methyl‐Xanthin
Authors: van Veen A. G. , Baars J. K. 
Published: September 2010

AbstractDas Toxoflavin, C6H6N4O2, ist ein gelber Giftstoff, welcher durch das Bacterium cocovenenans unter bestimmten Umständen aus Fettstoffen gebildet werden kann. Die Eigenschaften stimmen grossenteils überein mit denen des Lumi‐lactoflavins.Obschon ein Purin‐Derivat, zeigt die Substanz manche Eigenschaften, welche von denen der Purin‐Stoffe vollständig abweichen.Es gelang die Konstitution aufzuklären; das Toxoflavin ist isomer mit 1‐Methyl‐xanthin; die besondere Lage der Doppelbindungen erklärt die grosse Uebereinstimmung mit Alloxan wie auch die Farbe und sonstige Eigenschaften.
On aliphatic polyamines VII
Authors: van Alphen J. 
Published: September 2010

AbstractThe reaction between tetrakis‐bromomethyl‐methane and ammonia or different amines has been investigated and tetra‐primary, ‐secondary or ‐tertiary amines have been obtained. Tetrakis‐(methylamino‐methyl)‐methane has been studied more closely. This compound condenses very easily with aldehydes and forms tetra‐aza‐spiro‐undecane derivatives.
Interlamellare Quellung von Vakuumsubli‐Mierten CaF2‐Schichten Durch Adsorbiertes Caesium)
Authors: Dippel C. J. , de Boer J. H. 
Published: September 2010

AbstractThe object of this investigation was to determine the ratio of caesium and iodine molecules adsorbed on calcium fluoride layers, sublimed in vacuo and thereupon sintered, since this ratio was expected to fix the number of layers of caesium atoms that can be adsorbed on calcium fluoride. The fact that the adsorption of iodine on such sintered layers is much lower than on ordinary sublimed layers shows that the former possess fewer capillaries and interlamellar spaces than the latter (§ 1). However, the adsorption of caesium on a sintered and on a not‐sintered calcium fluoride surface turned out to be the same, in contradistinction to the adsorption of iodine, so that the ratio Cs/J2 increases enormously (§ 2, Tab. 1 and 2). The adsorption of caesium is not decreased until the surface is heated up to 450° C for several hours. (Tab. 4).Experimental evidence is given that the decrease of the adsorption of iodine and the constancy of the adsorption of caesium cannot be explained by considering the surface as “poisoned”, e.g. by adsorption of water molecules (§ 3). It is shown moreover that a sintered surface, to which temporarily caesium has been adsorbed, after removing the caesium exhibits with regard to the adsorption of iodine the normal value of an unsintered surface (§ 4). Thus the sintered surface can be broken up by caesium to its original size. This splitting up is described as an interlamellar swelling and must be distinguished from a swelling of the lattice (§ 5).
Die Addition und die Additionsprodukte der Halogene und Benzenderivate. IX: Die Addition von Chlor an Nitrobenzen
Authors: van der Linden T. 
Published: September 2010

AbstractDie Einwirkung von Chlor auf Nitrobenzen im Sonnenlichte wurde studiert. Es stellte sich heraus, dass einerseits Addition von Chlor an Nitrobenzen, andererseits Ersatz der Nitrogruppe durch Chlor und Addition von Chlor an die gebildeten Halogenbenzene stattfand.