bluuebunny/crossref_metadata_2025 huggingface dataset:
Die Nitrierung von 1‐Phenylpyrrol
Authors: Dhont J. , Wibaut J. P.
Published: September 2010

Bei der Nitrierung von 1‐Phenylpyrrol mit einem Gemisch von Schwefelsäure und Salpetersäure entsteht 1‐(4‐Nitrophenyl)‐pyrrol (Schmelzpunkt 181°); bei der Nitrierung von 1‐Phenylpyrrol mit einem Gemisch von Salpetersäure und Essigsäureanhydrid tritt die Nitrogruppe in den Pyrrolkern, so dass das 1‐Phenyl‐2‐nitropyrrol (Schmp. 108°) und das 1‐Phenyl‐3‐nitropyrrol (Schmp. 79°) entstehen. Die Struktur dieser drei isomeren Nitroverbindungen wurde auf verschiedene Weisen bewiesen. Aus den Nitroverbindungen wurden die übereinstimmenden Aminoverbindungen bereitet.
Die Krystallstruktur des Wolframhexachlorids
Authors: Ketelaar J. A. A. , van Oosterhout G. W.
Published: September 2010

Die Krystallstruktur des Wolframhexachlorids wurde röntgenographisch untersucht.

Elementarkörper: Rhomboedrisch a = 6.58 ± 0.01 Å

α = 55°0′

Hexagonal a = 6.088 ± 0.008 Å

c = 16.68 ± 0.05

Zahl der Moleküle: ein bzw. drei Moleküle WCl6.

drö =3.68 ± 0.02.

Raumgruppe C23i; W 1(a) ooo.

magnified image

Die Struktur lässt sich auffassen als eine deformierte hexagonale dichteste Kugelpackung der Chloratome, aufgebaut aus Molekülen WCl6 in der Form eines fast regelmässigen Oktaeders, mit W‐Cl:2.24 Å.
The formation of carbon dioxide and water in the oxidation of coal
Authors: Kreulen D. J. W.
Published: September 2010

The formation of CO2 and H2O in the oxidation of coal was studied at different temperatures. Coals, representing typical stadia of a coalification series were investigated.

The distinguishing feature of the experiments was the fact that the temperature throughout the reacting mass of coal was completely constant, this being the case in the experiments carried out below, as well as in those carried out above the ignition temperature.

The data obtained were analysed by the Kreulen‐ter Horst method.

From this it appeared that the formation of CO2 and H2O in the oxidation of coal is a reaction which takes place completely independently of the formation of humic acids.

The results, published previously by Parr and Miller, and also those of Francis and Morris, are discussed and explained as they are partially contradictory.
Condition of casein and salts, in particular Ca3(PO4)2, in milk
Authors: de Kadt G. S. , van Minnen G.
Published: September 2010

With the help of the Sharples Super‐centrifuge the casein was centrifuged out of skimmed milk, and the quite transparant gel, the whey belonging to it and the original milk were analyzed for dry weight, casein content, albumin, Ca, PO4 citric acid, Mg, K, Na, Cl and lactose.

From the results of the analysis for lactose and chlorine the bound water can be calculated: 0.55 gram per gram of casein was found.

Of the remaining constituents only Ca and PO4 are bound to any extent to the casein. If one subtracts from the PO4 that part which is bound as an ester in the casein and an equimolecular amount of Ca, the molecular ratio of Ca : PO4 becomes as 3 : 2, thus the same as in Ca3(PO4)2. This can be interpreted most simply as a complex:

or as a compound:
Properties and structure of sulfhemoglobin
Authors: Nijveld H. A. W.
Published: September 2010

This problem was investigated especially on account of the great number of controversies found in the literature. For a historical review reference is made to the papers of Michel2) and Jung3). A photoelectric colorimeter and a photoelectric spectrometer being of essential importance in this investigation, they are described first. Michel's observation that SHb contains per equivalent one sulphur atom more than normal hemoglobin, was confirmed by analysis of SHb prepared in vivo. This extra sulphur can be split off with bromine, but not with acid or alkali. The molecular weight of SHb is equal to that of normal hemoglobin (68000). By the action of dilute acid about five times as much iron is split off from SHb as from normal hemoglobin (“easily detached iron”). The absorption spectra of several derivatives of SHb are given. It is shown that potassium ferricyanide oxidizes the bivalent iron of SHb to trivalent iron. The compound formed can best be called ferrisulfhemoglobin. A rough calculation of the oxidation potential is given. The action of KCN on ferri‐SHb causes the extra sulphur to be split off from SHb. The spectrum of the compound formed is very similar to that of cyanhemoglobin. An analogous fact is found for the porphyrin and the hemochromogen which can be prepared from SHb. The difference in structure between globin hemochromogen and hemoglobin is discussed. The product formed by the action of hydrogen peroxide and ammonium sulphide on hemoglobin is not, as Michel presumes SHb, but it is probably identical with the verdohemochromogen found by Jung. Experiments are described which show that the empirical reaction equation for the formation of SHb is:

Further, an explanation is given of the fact that it is impossible to convert more than 75% of the Hb into SHb. In conclusion a hypothesis is given concerning the structure of SHb.
The lyotropic behaviour of bivalent cations
Authors: Büchner E. H. , Meylink B.
Published: September 2010

The depression of the melting point of gelatin by the chlorides of some bivalent metals is determined. The radius of the cation appears to be a dominating factor. The relation between the radius of the ion and the concentration of the salt causing a definite depression is different for cations and anions, and for univalent and bivalent cations. Calcium forms an exception, as it has very nearly the same effect as strontium. The anomalous behaviour of beryllium chloride is discussed.
Apparatus for measuring the consistency of plastic suspensions
Authors: van Selms F. G. , Kruyt H. R.
Published: September 2010

A description is given of two apparatus for measuring the rheological properties of suspensions, one according to Röder, and the other designed by the authors. The advantages and disadvantages of these two apparatus are considered.
The influence of traces of water on the plasticity of starch and quartz suspensions in organic media
Authors: Kruyt H. R. , van Selms F. G.
Published: September 2010

Suspensions of starch and quartz in CCl4 and similar media are plastic (thixotropic) only in the presence of water. The yield value is a function of the content of water. The relation between size of particle, water content and yield value was studied.
On a remarkable formation of isocarbostyril from isoquinoline
Authors: Wibaut J. P. , Haaijman P. W.
Published: September 2010

In connection with the formation. of 2,2′‐diquinolyl by catalytic dehydrogenation of quinoline at about 320° with the aid of a Ni‐Al2O3 catalyst, similar experiments were carried out with isoquinoline. When the latter base is heated with a Ni‐Al2O3 catalyst and the reaction product worked up, a small amount of isocarbostyril is formed; di‐isoquinolyl is not formed.
Die Einwirkung von Aryllithiumverbindungen auf Diarylketone. II. Bildung eines methylsubstituierten Derivats von 1,8‐Dioxy‐1,8‐Diphenyl‐2,3,6,7‐Dibenzcyclooctans bei der Reaktion von Phenyl‐ und 2,6‐Dimethylphenyllithium mit Bis (2,6‐Dimethylphenyl)keton
Authors: Faber Fräulein A. C. , Nauta W. Th.
Published: September 2010

Dem Produkt, das bei Einwirkung von Phenyl‐ oder 2,6‐Dimethylphenyllithium auf Bis(2,6‐dimethylphenyl)keton an Stelle des erwarteten Triarylcarbinols entsteht, muss die Struktur eines methylsubstituierten 1,8‐Dioxy‐1,8‐diphenyl‐2,3,6,7‐dibenzcyclooctans zuerkannt werden.

Bei den vierfach auf den Orthostellen mit Methylgruppen substituierten Diarylketonen tritt durch Einwirkung von Lithiumverbindungen als Zwischenprodukt eine Verbindung auf, welche Lithium in der Seitenkette enthält.
Die Polarisierbarkeit der Alkali‐ und Halogenionen
Authors: Böttcher C. J. F.
Published: September 2010

The polarizabilities of the alkali and halogen ions are calculated by means of a new method.

It is proved that the polarizabilities of the mononuclear ions are constant and not (as Fajans and Joos had to assume) dependent on the surroundings.

The values obtained for the alkali ions are in good agreement with those calculated by other writers; the values for the halogen ions are lower than those given by Fajans and Joos, but it is shown that the method they adopted in calculating them was incorrect.
Préparation de quelques 2‐amino‐sélénazols
Authors: Backer H. J.
Published: September 2010

Le mémoire décrit quelques 2‐amino‐sélénazols ainsi que leurs chlorhydrates, picrates et dérivés acétylés.
On the three‐phase pressures for solid salt‐solution‐vapour I
Authors: Korvezee A. E. , Dingemans P.
Published: September 2010

The “characteristic coefficient” k, which is connected with the concentrations and vapour pressures of saturated salt solutions and which was declared by Kume

T. Kume, Rev. Physic. Chem. Nippon 10, 73 (1936). Not to the found in a Netherlands library.

) to be a constant and characteristic quantity for each salt, is often found, when tested by the data in the literature, to depend very closely upon the temperature.

The relative vapour tension of these solutions, that is the vapour tension divided by that of pure water at the same temperature, indicates, with the addition of a correction, the activity of the water. A simple law is found to be approximately valid for this relative vapour tension: it varies along the three‐phase pressure curves almost always linearly or nearly linearly with the temperature.

The activity of the water in several saturated salt solutions is included in the tables.
A high temperature modification of NaNO2
Authors: Strijk B. , Mac Gillavry C. H.
Published: September 2010

NaNO2, orthorhombic hemihedral at ordinary temperature, shows an abrupt change in the temperature coefficients of the cell constants at about 158°C. At this same temperature the original strong piezo‐electric effect disappears. The change is very probably caused by the occurrence of two symmetrical sets of atomic positions in “averaged structure”.
Untersuchungen über Indolderivate I. Einleitung. Die Reaktion zwischen Phenacylbromid und primären und sekundären aromatischen Aminen
Authors: Verkade P. E. , Janetzky E. F. J.
Published: September 2010

Es wird gezeigt, dass die Bildung eines Indols aus einem Arylaminoketon, dem primären Produkt der Reaktion zwischen einem α‐Halogenketon und einem primären oder sekundären aromatischen Amin, zur Zeit allein die Konstitution des Endproduktes berücksichtigend, auf zwei Weisen erfolgen kann, welche durch die Formeln auf S. 771 veranschaulicht werden. Die Indolbildung findet “unter Umlagerung”, oder “unter Ringschliessung” statt.

Zur Indolbildung auf diese Weise ist die Anwesenheit eines Katalysators bezw. Pseudokatalysators erforderlich. Als solcher ist besonders das Hydrochlorid der Aminkomponente des Arylaminoketons brauchbar. Die Feststellung dieser Tatsache führte zu einer sehr erheblich verbesserten Ausführungsweise der betreffenden Synthese von im Pyrrolkern alkyl‐ und/oder arylsubstituierten Indolen.
Untersuchungen über Indolderivate. II ). Die Reaktion zwischen Methyl‐α‐brombenzylketon und primären und sekundären aromatischen Aminen
Authors: Verkade P. E. , Janetzky E. F. J.
Published: September 2010

Es wird die Reaktion zwischen Methyl‐α‐brombenzylketon und Anilin bezw. Monomethylanilin untersucht. Ausgehend von den hierbei primär gebildeten Arylaminoketonen, 1‐Phenyl‐1‐phenylamino‐propanon und 1‐Phenyl‐1‐phenylmethylamino‐propanon, werden mehrere Indole hergestellt.

Es wird gezeigt, dass die Unterscheidung zwischen Indolbildung unter Ringschliessung und Indolbildung unter Umlagerung nicht ausreichend ist. Im erstgenannten Falle ist eine weitere Differenzierung zwischen Indolbildung unter “wahrer Ringschliessung” und Indolbildung unter “scheinbarer Ringschliessung” erforderlich.
Pouvoir d'Addition de la Sulfone de Butadiène (Sulfones de Thiophane Substituées en Position‐3)
Authors: Backer H. J. , Strating J.
Published: September 2010

La sulfone cyclique non saturée qu'on obtient aux dépens de butadiène et d'anhydride sulfureux s'isomérise en milieu alcalin (déplacement de la double liaison). Outre cet isomère, il se forme le 3‐hydroxy‐1,1‐dioxothiophane, dont la structure est démontrée dans ce mémoire.

Ce composé doit avoir pris naissance par addition d'eau à la sulfone non saturée, probablement à la sulfone isomère.

II s'est révélé que ce pouvoir d'addition se manifeste également vis‐à‐vis d'autres réactifs. Les auteurs ont préparé des produits d'addition avec des alcools divers, avec un mercaptan et avec une amine.
The crystal structure of NaBiS2 and KBiS2
Authors: Boon J. W.
Published: September 2010

NaBiS2 and KBiS2 both have the NaCl structure with Bi3+ and Na+ (resp. K+) in averaged structure. The cell dimensions are 5.76 Å for NaBiS2 and 6.01 Å for KBiS2. The ionic radius of Bi3+ is discussed.
Sur la Dépendance de L'isotherme D'adsorption de la quantité d'adsorbant
Authors: Burgers W. G.
Published: September 2010

L'adsorption de l'acide acétique en solution aqueuse diluée (normalité 0.01‐0.4; volume de la solution 50 cm3) fut mesurée pour différentes quantités de charbon (1. 2 et 3 grammes). Tandis que la quantité adsorbée spécifique x/m (x = quantité adsorbée par m grammes de charbon) est une fonction décroissante de m, elle est une fonction uniforme de la concentration finale de la solution, indépendamment de la quantité d'adsorbant. Il s'en suit que l'adsorption se produit jusqu'à l'obtention d'un état d'équilibre et que, dans la rangée de concentrations et de quantités d'adsorbant appliquée, la diminution de x/m, m croissant, peut étre attribuée seulement à l'appauvrissement de la solution.
The crystal structure of α‐succinic acid
Authors: Rieck G. D.
Published: September 2010

The structure of the high‐temperature modification (α‐form) of succinic acid is not monoclinic as described in the literature, but triclinic. Its pseudo monoclinic habitus is caused by the formation of twins. The cell dimensions are determined. Although the atomic positions could not be determined exactly, it is shown that the structure of α‐succinic acid is closely related to that of adipic acid and the higher homologues of the series of even dibasic acids, and differs from those of both forms of oxalic acid and β‐succinic acid.
A kinetic investigation on the hydrolysis of simple aliphatic dicarboxylic tertiary butyl esters: Part I
Authors: Homan J. D. H.
Published: September 2010

The ratio k1/k2 of the alkaline saponification coefficients for the methyl and ethyl esters of the symmetrical aliphatic dicarboxylic acids, seems to be controled only by a statistical factor 2 and by the effect of the ionic centre in the mono‐ester anion, the hydrolysis of which is characterized by k2.

In accordance with the electron repelling effect of the tert. butyl group, a deviating value for k1/k2 in the case of the tert butyl esters was expected. We have studied these esters and compared the data with those of the corresponding methyl and ethyl esters. The latter esters were measured by Ingold in aqueous solution. Since the ditert butyl esters are insoluble in water, they had to be saponified in dioxane‐water mixtures.

The kinetic salt and medium effects, which arise upon saponifying the neutral esters and the mono‐ester anions, were studied.

A method for finding k2, free of salt effects, is indicated. Furthermore a method is described by which one can deduce k1 for the neutral esters in water from the constants in dioxane‐water mixtures.
Preparation of 4‐pyridylmethanal
Authors: Wibaut J. P. , Kooyman E. C. , Boer H.
Published: September 2010

A method is described for the preparation of the substance 4‐pyridylmethanal, which has not hitherto been mentioned in the literature, as well as of several derivatives of this compound. The aldehyde is obtained by the action of ozone on 4‐styrylpyridine in hydrochloric acid solution.
On bromopyridines: (59th communication on derivatives of pyridine and quinoline)
Authors: den Hertog H. J.
Published: September 2010

Descriptions are given of different methods of preparation and proofs of the structure of six bromopyridines (2,3‐dibromo‐, 2,4‐dibromo‐, 3,4‐dibromo‐, 2,3,4‐tribromo‐, 2,4,5‐tribromo‐, and 2,3,4,5‐tetrabromopyridine), while at the same time some of their chemical properties, in particular their reaction with ammonia, are discussed.

In conclusion a survey is given of some of the physical properties of the bromopyridines which are now all known; the boiling points of these substances were determined anew.
Atomic polarization and spectral data
Authors: Dekker A. J.
Published: September 2010

Zur Berechnung von Dipolmomenten ist in manchen Fällen die Kenntnis des Anteils der Ultrarot‐Schwingungen an der gesamten Polarisation erforderlich. Die experimentelle Bestimmung von Pa ist meistens sehr schwer, besonders wenn Messungen der Dielektrizitätskonstante an Gasen ausgeführt werden müssen. Es wird eine Methode angegeben, um diese Ultrarotanteile abzuschätzen, wenn Daten aus Raman und Ultrarotspektren vorliegen. Die Berechnungen sind im Anschluss an die Theorie von Mecke für einige Substanzen durchgeführt worden: 3‐atomige (gestreckte und gewinkelte), tetraëderförmige und einige substituierte Benzenmoleküle werden diskutiert.
On a hitherto unobserved 3‐pyridine compound occurring in human urine
Authors: Roggen J. C.
Published: September 2010

Im menschlichen Harn kommt ein 3‐Pyridinderivat vor, das sich nach saurer oder alkalischer Hydrolyse des Harns nicht nachweisen lässt, da es keine oder eine nur sehr schwache König'sche Reaktion giebt.

Diese Verbindung ist verschieden von allen bisher beschriebenen Abkömmlingen der Nikotinsäure und entsteht auch nicht aus solchen während der Aufarbeitung des Harns. Nach Verabfolgung von Nikotinsäure scheint die Menge etwas zuzunehmen.

Es wird eine Bestimmungsmethode angegeben; die Substanz lässt sich durch energische Permanganatoxydation zu Nikotinsäure abbauen.
Substituted 2‐phenylazocrotonic acid esters: (The reaction between α‐halogen ketones and phenylhydrazine derivatives II )
Authors: van Alphen J.
Published: September 2010

Substituted 2‐phenylazocrotonic acid esters were prepared by the action of phenylhydrazines substituted in the phenyl nucleus on 2‐chloroacetylacetic acid ethyl ester, and the reaction of several reagents on the product was investigated. In contrast to the case with the unsubstituted 2‐phenylazocrotonic acid ethyl ester, the product of the action of ozone or nascent hydrogen could here be isolated in a pure state in several cases.
Teneur en Hydrates de Carbone et „Facteur D'albumine”︁ de la Chair de Moule (II)
Authors: Gerritsen D. J. , van Pelt J. G.
Published: September 2010

Pendant toute une année, nous avons, à peu près tous les quinze jours, determiné les cendres, les matières grasses, l'azote et les hydrates de carbone dans des moules.

Les valeurs que nous avons trouvées (par détermination directe) pour la teneur en hydrates de carbone se révèlent beaucoup plus élevées que celles qui ont été trouvées par Vande Velde (également par détermination directe, mais par un autre procédé) mais sont inférieures aux valeurs qui sont données dans la littérature et qui sont obtenues en effectuant la soustraction: 100 ‐ (cendres + graisses + N × 6,25).

Nos déterminations conduisent à un “facteur d'albumine” d'une valeur moyenne de 7,0. Les écarts de cette moyenne sont cependant tels que le calcul de la teneur en hydrates de carbone à partir de cette valeur moyenne du “facteur d'albumine” doit étre, en général, déconseillé.
Inhibition, induction and the Chain‐reaction theory, III. Inhibition by Sulphur
Authors: Jorissen W. P. , van Calcar E. S.
Published: September 2010

Sulphur retards the autoxidation of pinene and benzaldehyde and thereby impedes the formation of peroxides. The sulphur is found to be oxidized in a small measure.
The orientation of the COOC2H5‐group in the condensation product of malonic ester and β‐aminocrotonic acid ester
Authors: Kooyman E. C. , Wibaut J. P.
Published: September 2010

A proof is given that in the condensation product formed by the interaction of malonic ester and β‐aminocrotonic acid ester, namely 2‐methyl‐4,6‐dihydroxypyridine‐carboxylic acid ester, the COOC2H5‐group occupies the 5‐position.

This was effected by exchanging the hydroxyl groups for chlorine atoms and subsequently replacing these atoms by hydrogen atoms. The structure of the resulting 2‐methylpyridine‐carboxylic acid ester was established by conversion into the corresponding picrate, carboxylic acid and amide. The identities of these compounds with 2‐methylpyridine‐5‐carboxylic acid ester‐picrate, 2‐methylpyridine‐5‐carboxylic acid and ‐amide were proved by mixed melting points with samples of these substances prepared from 2‐methyl‐5‐ethyl‐pyridine.
Computation of the radius and the polarizability of a number of ions
Authors: Böttcher C. J. F.
Published: September 2010

From measurements of the refractive index and the density of aqueous electrolyte solutions, the radius and the polarizability of the ions Cl−, Br−, I, NO3−, ClO4−, SO4−, NH4+, Rb+, Cs+, Sr++ and Ba++ are calculated, also the polarizability of the ions Na+, K+ and Ca++.
La disulfanilylguanidine
Authors: Backer H. J. , Moed H. D.
Published: September 2010

Ce mémoire décrit la préparation et les propriétés de la disulfanilyl‐guanidine. Son activité antibactérienne “in vitro” est plus faible que celle de la sulfanilyl‐guanidine. “In vivo” elle ne présente pas d'activité.
The reaction between α‐halogenoketones and some hydrazine derivatives: (The reaction between α‐halogenoketones and phenylhydrazine, IV)
Authors: van Alphen J.
Published: September 2010

The reactions between some α‐halogenoketones and benzoylhydrazine or 4‐phenylsemicarbazide have been investigated. In these cases it appears that compounds with the grouping, ‐N: N‐C: C‐, are not produced, or at least not directly.
Determination of the structure of some tetrachloropropenes by means of Raman spectra
Authors: Gerding H. , Prins H. J. , Rijnders G. W. A.
Published: September 2010

A tetrachloropropene mixture obtained by the action of alcoholic potash solutions upon 1,1,2,3,3‐pentachloropropane was fractionally distilled in a vacuum. The Raman spectra of the fractions and of the hexachloropropanes obtained by addition of chlorine to the two head fractions of practically constant boiling temperature proved that chiefly two stereoisomers (cis and trans) are present, accompanied by a small amount of the third possible isomer 1,1,3,3‐tetrachloropropene‐1 in the highest boiling fraction. The two stereoisomers could be isolated; they are present in about the same amount.
Humin from hydroxymethylfurfuraldehyde
Authors: Blanksma J. J. , Egmond G.
Published: September 2010

Pure hydroxymethylfurfuraldehyde when heated in aqueous solution under pressure to 130° in presence of a small amount of oxalic or hydrochloric acid affords a black, carbonaceous humin, which agrees completely in characteristics and in composition with the humin produced as a by‐product in the preparation of laevulic acid by boiling hexoses with dilute sulphuric or hydrochloric acid, thus proving that hydroxymethylfurfuraldehyde is an intermediate product in the formation of humin from hexoses.
On the sweet taste of the 1‐halogeno‐2‐amino‐4‐nitrobenzenes
Authors: Blanksma J. J. , van den Broek W. J. , Hoegen D.
Published: September 2010

It has been shown previously that 1‐alkoxy‐2‐amino‐4‐nitrobenzenes are very sweet compounds

J. J. Blanksma and P. W. M. van der Weyden, Rec. trav. chim. 59, 629 (1940).

). The 1‐halogeno‐2‐amino‐4‐nitrobenzenes have now been investigated as a continuation of this research. These compounds are also sweet. The heavier the atomic weight of the halogen atom the sweeter is the taste and the higher the melting point, while the volatility in steam and the solubility in water decrease. The melting points and the degree of sweetness are given in a table. The acyl derivatives are tasteless. 1‐Halogeno‐2‐nitro‐4‐aminobenzenes are tasteless, non‐volatile in steam and their acyl derivatives are also tasteless.
Order‐disorder transformations in the lattice of organic molecules. III.: The crystal structure of C(SCH3)4 above 23.2°C
Authors: Perdok W. G. , Terpstra P.
Published: September 2010

In this article the crystal structure of tetramethyl‐orthothiocarbonate C(SCH3)4 above 23.2° C is described. Modification II, which is stable between 23.2 and 45.5° C is tetragonal, space group I 4/mmm (D174h), Z = 2, a = 8.17 Å, c = 7.96 Å.

Modification III, which is stable from 45.5° C up to the melting point at 65.7° C is cubic, space group Im3m (09h ), Z = 2, a = 8.15 Å. The symmetry of the molecule can be brought into agreement with the high point symmetry of its position in the lattice, if it is assumed a) that the CS4 group can occupy a number of equivalent positions in the packing of the methyl groups and b) that the methyl groups can occupy more than one position with respect to the CS4 group.
Diameter changes of gelatinized coacervate drops of the complex coacervate gelatine‐gum arabic resulting from a change in the pH of, or from the addition of neutral salts to the surrounding medium. I
Authors: de Jong H. G. Bungenberg , Landsmeer J. M. F.
Published: September 2010

1. A microscopic method is developed for the measurement of diameter changes of gelatinized coacervate drops.

2. The influence of the pH and with constant pH (3.7) the influence of neutral salts is investigated on the gelatinized complex coacervate gelatine (positive)‐gum arabic (negative).

3. Upon variation of the pH the diameter passes through a minimum lying very close to the pH (3.7) at which, with the given ratio of mixing of gelatine and gum arabic, complex coacervation is optimum (where for example the water content of the coacervate is a minimum).

4. In the regions of smaller salt concentrations the diameter changes are reversible, at higher concentrations irreversible.

5. The reversible change due to the addition of a salt is a swelling. For this swelling the double valence rule holds:

3‐1>2‐1 > 1‐1 and 1‐3 > 1‐2 > 1‐1.

6. The position of the minimum of the swelling‐pH curve, the swelling with salts and the thereby prevailing double valence rule are in agreement with the conception that in the gelatinization of the complex coacervate the typical complex relations (electrostatic attraction versus water content) have been retained. The complex gel which results is distinghuised from the complex coacervate only by the coherence of the positively charged gelatine to a gel structure.
Untersuchungen über Indolderivate. VII . Die Reaktion zwischen Methyl‐α‐bromäthylketon und primären und sekundären aromatischen Aminen
Authors: Janetzky E. F. J. , Verkade P. E.
Published: September 2010

In Fortsetzung von früheren Untersuchungen wird die Reaktion von Methyl‐α‐bromäthylketon mit mehreren primären aromatischen Aminen (Anilin, o‐, m‐ und p‐Toluidin, p‐Bromanilin und p‐Anisidin) und mit zwei sekundären aromatischen Aminen (Monomethyl‐ und Monoäthylanilin) untersucht.
Investigations in the purine series. II. Synthesis of some purine derivatives
Authors: Ruttink J.
Published: September 2010

Syntheses of xanthine, 3,7‐, 1,3‐ and 1,7‐diethyl‐ and of 3‐ and 7‐monoethyl‐xanthines are described in this publication
Optical rotation and atomic dimension. Experimental progress on the walden inversion
Authors: Brauns H.
Published: September 2010

In continuation of the series of articles on optical rotation and atomic dimension, an improved method of chlorination, bromination an iodination has been devised and applied to optically active methylpropylcarbinol and methylhexycarbinol. The results show not only that the parallelism between optical rotation and atomic dimension, which was postulated at the beginning of this series, is confirmed, but further that progress has been made in insight into the Walden inversion.
Identification of crystalline organic compounds by means of X‐ray analysis
Authors: de Lange J. J. , Houtman J. P. W.
Published: September 2010

Simple comparison of X‐ray diagrams of crystalline organic derivatives can be a very useful method for identification purposes.

The X‐ray patterns of the 2,4‐dinitrophenylhydrazones of several carbonyl compounds and of the 3,5‐dinitro benzoic acid esters of some alcohols were compared using Astbury's recording technique.

The differences in melting point of several samples of the 2,4‐dinitrophenylhydrazone of acetaldehyde are not due to different crystal structures, but are merely the result of irremovable contaminations.
Untersuchungen über indolderivate. X . Einige von 2,3‐Dimethylindol abgeleitete Bz‐Carbonsäuren
Authors: Verkade P. E. , Lieste J.
Published: September 2010

Es wird die Synthese der vier theoretisch möglichen 2,3‐Dimethylindol‐Bz‐carbonsäuren, ausgehend von Methyl‐α‐bromäthylketon und einem aminobenzoesauren Ester, beschrieben.
On the structure of leucaenine (leucaenol) 3rd communication
Authors: Wibaut J. P. , Kleipool R. J. C.
Published: September 2010

N‐methyl‐3‐hydroxypyridone‐4 has been synthesized from meconic acid and methylamine. This synthetic product is identical with the N‐methyl‐hydroxypyridone that has been obtained by Bickel and Wibaut as a decomposition product from leucaenine (leucaenol).
Properties and constitution of the peroxides prepared oxidizing propane and their analysis
Authors: Kooijman P. L. , Ghijsen W. L.
Published: September 2010

The present publication describes the experimental facts which led to the assumption that the aqueous peroxide solutions formed by incomplete oxidation of propane consist mainly of a mixture of hydrogen peroxide and the lower aldehydes and their association products, the hydroxyalkylhydro peroxides and the dihydroxyalkyl peroxides.

Further an analytical method is given for the determination of the total active oxygen content; for the determination of the free hydrogen peroxide content a method has been worked out yielding the approximate content. Moreover, the values obtained by this method are compared with the free hydrogen peroxide content calculated from the equilibrium constants.
The system NH4NO3  AgNO3  Pb(NO3)2  H2O
Authors: Dingemans P. , Dijkgraaf L. L.
Published: September 2010

As a continuation of a number of previous investigations of the binary combinations of the salts NH4NO3, AgNO3 and Pb(NO3)2, the meltingpoint diagram of the ternary system has now been studied. The ternary eutectics were of special interest.

Furthermore the vapour pressures of the following systems were measured:

solutions in water saturated with respect to Pb(NO3)2 + NH4NO3. AgNO3 + NH4NO3 from 10°C to the ternary eutectic at 97.4°C.

solutions in water saturated with respect to Pb(NO3)2 + NH4NO3. AgNO3 + AgNO3 from 10°C to the ternary transition point at 107.9°C.

These are the first cases in which the entire course of the vapour‐pressure line has been measured for solutions saturated with respect to three salts. Both lines show the customary form with a maximum, many cases of which are already known for solutions saturated with respect to one or two salts.

For these quaternary systems also, the relative vapour‐pressure line was also found to be almost straight, as had already been found in this laboratory for several binary and ternary systems.

A formula for the calculation of the maximum in the vapour‐pressure line, previously derived for solutions saturated with respect to one salt, was also found to be applicable to these solutions saturated with respect to three salts.
Des Quinoléines Substituées: VI. Dérivés macrocycliques de la quinoléine
Authors: Hoï Ng. Ph. Buu‐ , Royer René
Published: September 2010

Dans le présent mémoire, il est montré que les cyclanones à très grand cycle peuvent réagir avec l'isatine et ses homologues dans les conditions de la réaction de Pfitzinger. Les acides cinchoniniques substitués en positions 2 et 3 par un grand cycle qui prennent ainsi naissance fournissent par décarboxylation des quinoléines macrocycliques, non odorantes.
Untersuchungen über Indolderivate. XI: Die Reaktion zwischen Monobromacetaldehyd‐diäthylacetal und primären und sekundären aromatischen aminen
Authors: Janetzky E. F. J. , Verkade P. E. , Meerburg W.
Published: September 2010

Es wird die Reaktion zwischen Monobromacetaldehyd‐diäthylacetal und primären und sekundären aromatischen Aminen untersucht. Dabei tritt das Arylaminoacetaldehyd‐diäthylacetal als primäres Produkt auf. Zwei neue Methoden zur Darstellung derartiger Substanzen werden beschrieben. Es gelang nicht hiervon ausgehend Indol bezw. Indolderivate zu erhalten.
The taste of 1‐alkoxy‐ and 1‐halogeno‐2‐amino‐4‐cyano‐benzenes
Authors: Blanksma J. J. , Petri E. M.
Published: September 2010

3‐Nitroaniline is 40 times and 3‐cyanoaniline 25 times as sweet as cane sugar. The taste of their derivatives, the 1‐alkoxy‐ and 1‐halogeno‐2‐amino‐4‐nitrobenzenes, which are very sweet, are now compared with those of the 1‐alkoxy and 1‐halogeno‐2‐amino‐4‐cyanobenzenes, which are also very sweet substances. The sweet taste diminishes when the nitro group is replaced by the cyano group. When the cyano group is hydrolysed to amido the sweet taste disappears.
Some properties of the ecgonines and their esters. VI. The calcium and lead salts of l‐ecgonine, the conversion of l‐ecgonine into l‐benzoylecgonine and its esterification with methyl alcohol and benzoic anhydride or benzoyl chloride
Authors: de Jong A. W. K.
Published: September 2010

The calcium salt of l‐ecgonine is soluble in methyl and ethyl alcohols and also in anhydrous benzene. It crystallises in fine needles. Ecgonine forms a compound with calcium chloride.

The lead salt also crystallises in needles and is readily soluble in alcohol and benzene.

An almost complete conversion of l‐ecgonine into l‐benzoylecgonine is obtained in 5 days at ordinary temperature in aqueous acetone with the addition of 2–3 times the theoretical quantity of benzoic anhydride.

By the action of benzoic anhydride and methyl alcohol on benzoylecgonine at ordinary temperature the anhydride of benzoylecgonine is formed as the main product, which can then give cocaine and benzoylecgonine with methyl alcohol. The conversion into cocaine obtained, however, by using 7 times the theoretical quantity of benzoic anhydride was only 80%.

Benzoylecgonine when treated with methyl alcohol and 3.5 times the theoretical quantity of benzoyl chloride at ordinary temperature gives an almost complete conversion into cocaine.
Investigations concerning polymerization of propene and ethene induced by various substances
Authors: Kooijman P. L. , Ghijsen W. L.
Published: September 2010

This publication presents a description of an experimental investigation on the induced polymerization of propene and ethene at an initial pressure of ∼ 250 at and at temperatures of 280‐375°C. A series of substances belonging to the metal alkyls, azo‐ and diazo compounds, nitro compounds, oximes and hydrazine derivatives, was found to accelerate the polymerization of these olefines.

With some exceptions, the polymerizing action of these substances is greater on ethene than on propene.

An investigation at varying reaction temperatures with some substances representing the above groups, showed that the initiator yield (i. e. the quantity of olefines in gmol polymerized under the influence of 1 gmol of the initiator) is probably determined by the number of free radicals formed per molecule in the thermal decomposition of these substances. At higher temperatures, the initiator yield decreases.

It was also found that the action of the above substances was not influenced when the wall surface area is increased by a factor of 6 by filling the autoclave with splintered glass. Impurities, such as water, sulphur and lubricating oil, when present in small quantities, have no appreciable influence on the reactions.

The available factual material hardly enables us to make any definite statements on the actual mechanism of these induced chain reactions.
Vapour pressures and heats of vaporization of cis‐ and trans‐1,2‐dichloroethene
Authors: Ketelaar J. A. A. , van Velden P. F. , Zalm P.
Published: September 2010

Vapour pressures of cis‐ and trans‐1,2‐dichloroethene have been measured over a temperature range from zero‐point up to about 90°C, using glass spring tensimeters of the type, applied in this laboratory for all determinations of this kind. Special care was taken in purifying the samples of the two isomers. Dielectric constant measurements were carried out in order to control the degree of purity of the samples. The values of the vapour pressures obtained are compared with those, determined by some authors in the past. Heats of vaporization and Trouton constants are derived from the measurements.
On the electrometric determination of vanadium in steels
Authors: Claassen A. , Corbey J.
Published: September 2010

Procedures are given for the electrometric determination of vanadium in alloy steels. In tungsten‐free steels vanadium is determined by titration with ferrous sulphate under specified conditions of acidity. It is shown that this method gives low results for steels containing tungsten, due to the incomplete reduction of the vanadophosphatotungstate complex; complete reduction however takes place by boiling with excess ferrous sulphate, enabling the determination to be finshed by electrometric titration with standard permanganate. Small amounts of vanadium accompanied by large amounts of tungsten can only be determined by titration with ferrous sulphate when the amount of phosphoric acid is greatly increased.
Röntgenographic observation of the ripening of silver bromide emulsions
Authors: Burgers W. G. , Kooy J. N.
Published: September 2010

Debye‐Scherrer photographs of silver bromide emulsions were taken before and after the emulsion had undergone a “ripening‐process” by keeping it at a temperature of about 40° C for a few hours. An increase of resolution of the Co‐Kα‐doublet of the AgBr‐line σ(H2 + K2 + L2) = 40 confirmed that the ripening‐process was accompanied by growth of the silver bromide crystals. It was further shown that this crystal growth took place in the first stage of the ripening‐process, before the soluble salts had been eliminated by rinsing.
Preparation and properties of 1,4‐dihydrobenzene and of the addition and substitution products produced from it by the action of bromine
Authors: Wibaut J. P. , Haak F. A.
Published: September 2010

1,4‐Dihydrobenzene has been obtained by reducing benzene by the method of Wooster and has been prepared in a pure state; the structure of this hydrocarbon is apparent from the formation of malonic acid and benzoquinone on oxidation. Some of its physical constants have been determined. The addition products with bromine. C6H8Br2 and C6H8Br4, are described.
Some properties of hydrocarbons having more than twenty carbon atoms
Authors: Mazee W. M.
Published: September 2010

The heat of fusion, heat of transition, specific heat, molecular refraction calculated by means of the Lorentz‐Lorenz equation, boiling point under reduced pressure, heat of evaporation and viscosity are given for a number of normal and branched alkanes and a cyclane, all having more than 20 carbon atoms.

The crystallographic properties of n‐heneicosane and n‐tetracosane at different temperatures are discussed.
Researches on the alkoxy‐amino‐nitrobenzenes: IV). Nitration of 1‐alkoxy‐2‐arylsulphonylaminobenzenes
Authors: Bosma G. S. K. , Meerburg W. , Verkade P. E.
Published: September 2010

The nitration of some 1‐alkyloxy‐2‐p‐toluenesulphonylaminobenzenes under different conditions is described. The results are discussed from a theoretical standpoint.
Études dans la Série du Thiophène: I. Cétones dérivées du 2,5‐diméthylthiophène (2,5‐thioxène) et certaines de leurs réactions
Authors: Buu‐Hoï Ng. Ph. , Nguyen‐Hoán
Published: September 2010

Dans ce travail, on décrit la synthèse et les propriétés d'une série de cétones dérivées du 2,5‐thioxène (2,5‐diméthylthiophène). Certaines des cétones aromatiques ainsi obtenues subissent aisément la réaction d'Elbs, et conduisent à des substances polycycliques appartenant au noyau du thiophanthrène; ces corps sont des isostères d'hydrocarbures du groupe de l'anthracène et du 1,2‐benzanthracène. Une nouvelle méthode de préparation commode est indiquée pour l'acide 2,5‐diméthyl‐3‐thenoïque, et plusieurs dérivés de ce corps sont décrits, ainsi que certains aryléthylènes dérivant du 2,5‐thioxène. L'étude de la réaction de Pfitzinger montre enfin que le noyau 2,5‐thioxène produit un empêchement stérique.
Energetic data on the carbon ‐ carbon bond IV. Energy of activation, arrhenius constant and period of half‐life for the radical‐dissociation reaction of six hydrocarbons of the pentaphenylethane type in o‐dichlorobenzene as a solvent
Authors: Coops J. , Galenkamp H. , Haantjes J. , Luirink H. L. , Nauta W. Th.
Published: September 2010

The energy of activation (E), the Arrhenius constant (A) and the period of half‐life at 80° (t1/2) for the radical‐dissociation reactions of the following compounds:

pentaphenylethane (I)

1,1,1,2‐tetraphenyl‐2‐(2‐methylphenyl)ethane (II)

1,1,1,2‐tetraphenyl‐2‐(3‐methylphenyl)ethane (III)

1,1,1,2‐tetraphenyl‐2‐(4‐methylphenyl)ethane (IV)

1,1,1‐triphenyl‐2,2‐di‐(3‐methylphenyl)ethane (V)

1,1,1‐triphenyl‐2,2‐di‐(4‐methylphenyl)ethane ((VI)

have been calculated from the velocity constants for the first‐order reactions of the radicals concerned with oxygen in o‐dichlorobenzene as a solvent:

magnified image
Kinetics of gas‐liquid reactions part I. General theory
Authors: van Krevelen D. W. , Hoftijzer P. J.
Published: September 2010

When a gaseous component is absorbed by a liquid under simultaneous reaction with a component of the liquid, the overall rate of reaction proves to be a dimensionless function of four limiting rates:

the maximum rate of diffusion of the gaseous component through the liquid film

the maximum rate of diffusion of the liquid‐component through the liquid film

the limiting rate of reaction within the liquid film (during diffusion)

the maximum rate of reaction within the main body of the liquid.

A graphical representation of the theoretical relationship enables one to predict the overall rates of interphase mass exchange under arbitrary conditions, as soon as reaction velocity coefficients and mass transfer coefficients are available.
Permanganometrische Untersuchungen III: Die Bestimmung der Azide und der Stickstoffwasserstoffsäure mit Kaliumpermanganat
Authors: van der Meulen J. H.
Published: September 2010

Méthode d'analyse volumétrique de l'acide azothydrique et des azotures au moyen de permanganate de potassium, préalablement réduit par un sel de manganèse bivalent en excès, en présence d'acide sulfurique et d'acide phosphorique.

L'excès de permanganate est dosé avec d'iodure de potassium par titrage de l'iode libéré au moyen de thiosulfate de sodium décinormal.
Etude sur les Oxydes de Thiouree. IV
Authors: Böeseken J.
Published: September 2010

La propriété fortement réductrice d'une solution ammoniacale du dioxyde de thiourée ne peut pas être attribuée à la formation passagère du sel d'ammonium de l'acide sulfoxylique, car les éthers éthyliques de cet acide, en solution alcaline, ne précipitent pas les sels de cadmium à l'état de cadmium métallique. Le dioxyde lui‐même doit être la cause de cette propriété remarquable.

Cependant, la décomposition en solution ammoniacale:

est prouvée par la présence, après quelque temps, des ions S2O3, SO4, SO3 et S. Le Ni et le Cd précipités contiennent toujours des quantités assez considérables de S et d'oxygène.

Le fait que le cadmium et tous les éléments plus électronégatifs provoquent un dégagement lent d'hydrogène peut être déduit de la place de l'hydrogène dans la série des forces électromotrices des éléments.

En solution ammoniacale, le dioxyde s'empare d'un atome d'oxygène: en présence des sels de Ni, Fe, Co, etc., deux atomes d'oxygène sont fixés; le soufre est alors transformé en sulfate. Cette réaction, partiellement catalytique, a étè étudiée de plus près.

La méthylthiourée donne avec H2O2 l'acide méthylformamidine‐sulfinique, qui montre les mêmes réactions que l'acide formamidine‐sulfinique lui‐même; en solution aqueuse et légèrement acide, il est un peu plus stable.

Enfin, nous avons étudié l'oxydation de la benzylisothiourée par H2O2, dans l'espoir d'obtenir l'éther benzylique de l'acide formamidine‐sulfinique, mais en vain.

En oxydant la benzylisothiourée par l'acide peracétique, nous avons obtenu une substance C23H17S3N3O5; dont nous avons établi la structure avec quelque probabilité.
A general method for quantitative spectrochemical analysis: (Preliminary communication)
Authors: Addink N. W. H.
Published: September 2010

Till now Gerlach's internal standard method has been applied to all kinds of quantitative spectrochemical analysis. According to this method it is necessary to prepare for each individual material to be analysed series of samples in order to set up working curves, relating concentration and intensity ratio of lines of the element sought for and the standard‐element.

Harvey (1947) uses the background near a line of the element as a kind of internal standard and his book contains many useful data for two‐component systems.

However, materials containing many major constituents as mixtures of salts, oxides or metals themselves cannot be analysed with great accuracy according to Harvey's method.

In the following paper a general method derived from Harvey's is described; it can be divided into two parts; one for the rough estimation of the element concentration and a second part for the exact determination, obtained by successive additions of the element sought for. If the straight portion of the characteristic curve of the photographic emulsion is used, a simple evaluation of the concentration is given whereas the knowledge of the accurate shape of the characteristic curve is not essential.
Ultraviolet absorption spectra and stereochemical structure of plant growth substances of the cis cinnamic acid type and of stilboestrol
Authors: Havinga E. , Nivard R. J. F.
Published: September 2010

Ultraviolet absorption spectra are recorded of cis‐ and trans‐ cinnamic acid, of cis‐ and trans‐1,2,3,4,‐tetrahydronaphthylidene (1) acetic acid and of cis‐ and trans‐β‐(naphthyl‐1) acrylic acid. The cis isomers all show a lower extinction coefficient and a shift of the maximum of absorption to shorter wave‐length in comparison with the trans isomers. It is concluded that as a result of steric hindrance in the case of the cis compounds the conjugation between aromatic ring system and carboxyl group is hindered, the molecules not possessing a plane structure. The fact that all these cis compounds show marked activity as plant growth promoter, whilst the trans isomers are totally inactive, is in accordance with the conclusions about their stereochemical structure. Comparison of the ultraviolet absorption spectra of stilboestrol and of p,p′‐dihydroxystilbene leads to the conclusion that the stilboestrol molecule does not have a plane structure and that it is doubtful whether the explanation of the oestrogenic activity based on its often suggested „formal”︁ similarity to the natural oestrogenic hormones is justified.