bluuebunny/crossref_metadata_2025 huggingface dataset:
The theory of measurement of osmotic pressure
Authors: Staverman A. J.
Published: September 2010

Application of Onsager's symmetry relations to the process of diffusion of a solution through a membrane shows that measured osmotic pressures deviate from those calculated thermodynamically in proportion to the permeability of the membrane to the solute molecules. Therefore little is learned from one dynamic osmotic measurement but by simultaneous measurements of osmotic pressure and permeation at different membranes the entire molecular weight distribution of the solute can be computed.
Isomérisation de sulfones β‐oléfiniques en sulfones α‐olefiniques et son influence sur leur pouvoir d'addition: (Propriétés du groupe sulfonyle XIX)
Authors: Backer H. J. , de Jong G. J.
Published: September 2010

De mème que la benzylallylsulfone3), ses dérivés méthyles en position α et β s'isomérisent sous l'influence d'un accepteur de protons, la double liaison se rapprochant du groupe sulfonyle. L'isomérisation de la benzylcrotylsulfone ne réussit pas dans les mêmes conditions.

A moins qu'un substituant en position α n'encombre l'addition, les sulfones α‐oléfiniques qui résultent de l'isomérisation fixent des réactifs nucléophiles, ainsi que l'eau, l'alcool, le phénol et les mercaptannes en solution alcaline et la pipéridine.

Le mécanisme des réactions d'isomérisation et d'addition est étudié et discuté en rapport avec les réactions analogues que présentent les sulfones cycliques des butadiènes.
The dehydrogenation of hydrocarbons by means of quinones: I. action of Chloranil
Authors: Dost N. , van Nes K.
Published: September 2010

The dehydrogenation of hydrocarbons with the aid of chloranil (tetrachloro‐p‐benzoquinone) is investigated.

According to the literature, thus far all hydrocarbons dehydrogenated by this quinone invariably have proved to contain a partially hydrogenated aromatic nucleus. It has been shown in the present study that those hydrocarbons which contain a —CH—CH— group adjacent to an aromatic nucleus or to a double bond may be dehydrogenated by chloranil (at about 140° C). On the other hand it is impossible to dehydrogenate perhydro‐aromatics and aliphatics under the same conditions.

When aliphatic olefins and cyclopentene derivatives are treated with chloranil, consecutive reactions prohibit the isolation of initially dehydrogenated products.

The reaction mechanism of the dehydrogenations is discussed. The experiments are in line with the view that the reaction involves a free radical mechanism.
Quantitative investigation of the ozonisation of quinoline, isoquinoline and some of their homologues
Authors: Boer H. , Sixma F. L. J. , Wibaut J. P.
Published: September 2010

The addition of ozone to quinoline, 2‐ and 8‐methylquinoline, 2,3‐, 3,4‐ and 6,7‐dimethylquinoline and isoquinoline has been studied quantitatively.

With the quinoline homologues the main initial reaction is an attack of the benzene ring, probably with the formation of a monozonide, which was rapidly converted into a 5,6‐, 7,8‐diozonide; the diozonide then reacts slowly to form a 3,4‐, 5,6‐, 7,8‐, 9,10‐tetraozonide. As a side reaction the pyridine nucleus is attacked initially; however this side reaction leads to the same tetraozonide.

Isoquinoline adds on one molecule of ozone in the pyridine nucleus to the extent of about 60 % and two molecules of ozone in the benzene ring to an extent of 40 %.

In none of the compounds examined was there any indication of the addition of ozone to a C=N bond.

These conclusions, based on a determination of the quantities of ozone taken up, the amount of quinoline reacted and the amount of ammonia formed when the reaction product is hydrolised, are in agreement with the qualitative results of the ozonolysis of quinoline bases already published. 1)
Non‐newtonian flow of dilute polymer solutions: I. Outline of the Method
Authors: De Wind G. , Hermans J. J.
Published: September 2010

A method is developed for the study of non‐Newtonian behaviour of dilute polymer solutions with a view to extrapolating the results obtained to infinite dilution. This method will be applied in the second part.

The use of the capillary viscometer for this kind of work is discussed. As a check on the equation used some measurements with water, benzene and acetone are reported.
Tannin as a reagent for zirconium
Authors: Purushottam A. , Rao Bh. S. V. Raghava
Published: September 2010

The use of tannin in separating zirconium from other elements has been investigated. With the exception of tin and titanium almost all elements commonly associated with zirconium may be separated in a single or a double precipitation in 0.1 N to 0.15 N‐hydrochloric acid solution. It is shown further that tannin gives a definite turbidity with as little as 0.002 mg of ZrO2 per ml and quantities of 0.6 mg and over may be conveniently estimated with the reagent.
Esters spirocycliques des acides tetrathioorthosilicique, ‐orthogermanique et‐orthostannique
Authors: Backer H. J. , Drenth W.
Published: September 2010

L'éthanedithiol réagissant à l'état de mercaptide sur les tétrachlorides de silicium, de germanium et d'étain donne naissance à des thioéthers spirocycliques, qui fondent à des températures assez élevées. Les produits dont le germanium et l'étain constituent l'atome central cristallisent dans le système orthorhombique.
Addition de reactifs nucleophiles a la diallysulfone: (Propriétés du groupe sulfonyle XX )
Authors: Backer H. J. , van der Ley R.
Published: September 2010

La diallylsulfone fixe, en solution alcaline, les réactifs nucléophiles, L'addition d'eau, d'hydrogène sulfuré et d'ammoniac conduit à des sulfones cycliques.
Reactions with boron fluoride ether
Authors: van der Zanden J. M. , de Vries G.
Published: September 2010

Some time ago 1) we described the formation of cinnamaldehyde by the action of boron fluoride ether on benzaldehyde. We suggested a possible mechanism of reaction: benzaldehyde gives benzyl alcohol by a Canizzaro reaction. The latter then reacts with boron fluoride ether with the formation of benzyl ethyl ether and ethyl alcohol. Dismutation of ethyl alcohol with benzaldehyde then gives acetaldehyde, which condenses with benzaldehyde to form cinnamaldehyde.

In order to obtain support for the above suggestion we have made attempts to detect the presence of benzyl ethyl ether in the reaction mixture.
Non‐Newtonian flow of dilute polymer solutions: II Solutions of cellulose nitrate in acetone
Authors: de Wind G. , Hermans J. J.
Published: September 2010

The method outlined in part I *) is applied to solutions of cellulose nitrate in acetone. It is found that the non‐Newtonian character of the flow is strongly dependent on the polymer concentrations, but does not persist at the limit of infinite dilution. In other words, the non‐Newtonian character of the flow is not an intrinsic property of the polymer molecule but results from molecular interactions.

The concentrations were varied between 0.05 and 0.2 g/100 ml. In one series we went up to 0.8 g/100 ml. The highest gradient attained was about 5.104 sec−1.
Studies in alums: I. Tetramethylammonium and aluminium
Authors: Zernike J. , Basak Radharaman
Published: September 2010

Preparation of (CH3)4NAl(SO4)2. 12H2O. Determination of density, solubility and melting point.
The second virial coefficient of benzene
Authors: Korvezee A. E.
Published: September 2010

A one‐parameter family of curves for the second virial coefficient of benzene as a function of temperature is computed from caloric precision measurements.

The formulae given by Hirschfelder c.s. and by van Laar for B(T) are compared with this experimental temperature relation.
The influence of cations on the gelatin gel: II. The influence on swelling
Authors: Nobel P. C.
Published: September 2010

Swelling experiments have been carried out with gelatin in solutions of the chlorides of the alkali and alkaline earth metals. In the alkaline earth metals series, swelling appears to increase with the equivalent conductance of the cations. The relationship is not linear. Calcium chloride and strontium chloride solutions give equal swelling values. With the alkali chlorides a more or less hyperbolical relationship was found between swelling and ionic radii. The water contents of gelatin swollen in sodium chloride, potassium chloride or rubidium chloride appear to be practically identical. Lithium chloride and caesium chloride give a higher water content.
La réaction de composés diazo sur les bis‐alcoylsulfonyl‐méthanes: Propriétés du groupe sulfonyle xxi
Authors: Backer H. J.
Published: September 2010

Contrairement à l'opinion courante les composés diazo réagissent sur les 1,1‐disulfones en donnant naissance à de vrais composés azo. Ces azo‐disulfones sont solubles dans les alcalis avec une couleur jaune intense. Au moyen d'un excès de diazobenzène on peut introduire deux groupes azo. La bis‐azo‐disulfone paraît être instable. L'hydrolyse effectue un décrochage des groupes alcoylsulfonyle en donnant naissance à un dérivé de l'aldéhyde formique. L'hydrolyse partielle, suivie de la réaction avec une molécule d'azodisulfone, conduit à un éther.
The properties of the electrical double layer IV: The stability of the AgI sol in water‐acetone mixtures
Authors: Mackor E. L.
Published: September 2010

The electrolyte concentration at rapid flocculation of the AgI sol is measured in water‐acetone mixture for NaClO4, Ba(ClO4)2 and La(ClO4)3. There is a large drop in this value at high concentrations of acetone as is predicted in Verwey and Overbeek's theory of stability1). At medium acetone concentrations the AgI sol is stabilized, contrary to expectation.

The theory of stability is extended on the basis of a model with double layers of Gouy‐Stern type on flat interacting parallel plates2). This theory explains the measured values if one assumes an attraction of the van der Waals‐London type. This attraction energy should be inversely proportional to d1.6 instead of to the square of the inverse distance, as is calculated by de Boer and Hamaker3).
Preparation et scission du phenylazo‐methylthio‐bis‐methylsulfonyl‐methane: Propriétés du groupe sulfonyle XXII
Authors: Backer H. J.
Published: September 2010

L'introduction du groupe phénylazo dans le méthylthio‐bis‐méthyl‐ sulfonyl‐méthane donne un produit jaune peu stable. Ce produit est attaqué selon trois manières differentes par les acides, les bases et la pipéridine, qui décrochent un groupe phénylazo, méthylsulfonyle et méthylthio respectivement.
The electrokinetic behaviour of freshly prepared γ‐AlOOH, α‐ and γ‐Al(OH)3
Authors: van Schuylenborgh J.
Published: September 2010

It was shown that the electrokinetic behaviour (especially the isoelectric pH value) of Al‐hydroxides depends very strongly on their mode of origin. There is a close connection with the dehydration temperatures, with phosphate‐adsorption and with the results of Röntgenographic analysis.
The preparation of pyridine derivatives from halogenopyridines by means of the Grignard Reaction IV: Synthesis of bis‐(pyridyl‐2) ketone
Authors: de Jonge A. P. , Hertog H. J. Den , Wibaut J. P.
Published: September 2010

Bis‐(pyridyl‐2) ketone has been synthesised by treating 2‐iodopyridine with magnesium in the presence of ethyl bromide and reacting the 2‐pyridylmagnesium iodide complex so obtained with ethyl picolinate. Ethyl‐bis‐(pyridyl‐2)‐carbinol and tris‐(pyridyl‐2)‐carbinol were formed as by‐products.
Identity of anomalous product reported in synthesis of dimethallyl
Authors: Gaylord Norman G.
Published: September 2010

The product, b.p. 136°, reported in the reaction between methallyl chloride and magnesium, is identified as diisocrotyl (2,5‐dimethyl‐2,4‐hexadiene) resulting from rearrangement of dimethallyl, b.p. 114°.
Activated adsorption of hydrogen on nickel catalysts
Authors: Schuit G. C. A. , de Boer N. H.
Published: September 2010

The chemisorption of hydrogen on a Ni‐catalyst obtained by coprecipitation from Ni(NO3)2, Na2CO3‐ and Na silicate solutions at 80° C and containing Ni and SiO2 in the ratio 3 Ni‐1 SiO2 was investigated.

In agreement with other investigations it was found that the adsorption consists of a very rapid process followed by a much slower one, the latter increasing in velocity with increasing temperature. The transition between the two is not sharp but gradual. However, some distinction may be made by observing the amounts of hydrogen adsorbed at liquid nitrogen temperatures and very low pressure (type I) and the amounts which can be adsorbed in excess of this quantity (type II).

It was found that a more thorough reduction of the catalyst resulted in an increase of the type I adsorption at the cost of type II. Adsorption of oxygen on a well‐reduced catalyst on the contrary decreased the type I and increased the type II adsorption, the change being linear with the amount of oxygen adsorbed. Oxygen adsorption can occur in two different manners. It is assumed that depending on the conditons one adsorption site can be occupied by either an oxygen atom or an oxygen molecule.

Heating of a reduced catalyst in an inert atmosphere or under vacuum tends to eliminate the type I adsorption while also the total adsorption diminishes. It is suggested here that a reoxidation of the surface occurs (combined with some sintering). Two causes for this reoxydation are considered:

diffusion of oxygen in the interior of the metal—metaloxide structure to the surface

liberation of water vapour by the silica carrier followed by the reaction

Ni + H2O → NiO + H2.
Researches on plant growth regulators XXI. Structure/activity VI. Halogenated benzoic acids and related compounds
Authors: Veldstra H.
Published: September 2010

On account of the high activity reported for 2,3,6‐trichlorobenzoic acid (Bentley

J. A. Bentley, Nature 165, 449 (1950).

)), at first sight lacking the spatial relation between—COOH group and ringsystem occurring in the active compounds known until now, the series of substituted benzoic acids was studied more closely. From the six isomeric trichlorobenzoic acids, now investigated in the pea‐test, only the 2,3,6‐trichloro acid proves to be highly active. From their U.V.‐absorption spectra it is deduced that with the di‐ortho (2,6) substituted acids steric inhibition of resonance occurs. In this way the tendency of the molecule to occur in a flat form on account of conjugation is counteracted. Consequently in the undissociated acid the dipole vector of the —COOH group will be at an angle with the plane of the ringsystem. For this reason the active substitued benzoic acids are considered in essence to be equivalent to the types of active compounds studied before, realizing a three‐dimensional amphipatic structure in a special way, namely by steric inhibition, especially of factors favouring coplanarity. 2,6‐Dichlorobenzoic acid, showing the same inhibition, is found to be physiologically active too and arguments are given that very probably the weak activity of α‐naphthoic acid has to be explained along the same lines. When in the latter acid the steric inhibition of resonance is intensified (as appears from the U.V.‐spectra) by chlorine‐substitution in the β‐position, for the resulting β‐chloro‐α‐naphthoic acid an increased activity is found, this being practically the same as that of 2,3,6‐trichlorobenzoic acid.
L'influence du Bromure D'hexadecyltrimethylammonium sur L'inhibition de la Respiration des Levures Causée par des Ions Metalliques
Authors: Massart L. , Schoon J.
Published: September 2010

Le but de cette recherche est de voir si le mécanisme d'action des cathions toxiques est basé sur un même principe et s'exerce au même endroit. Pour mettre ces faits en évidence il est fait appel au bromure de cétyltriméthylammonium, cathion organique, qui exerce son activité en premier lieu à la surface cellulaire et qui sert en somme comme agent différenciant.
Properties and reactions of molecules at interfaces I. Theoretical remarks on ionic concentrations in the neighbourhood of monolayers containing charged groups)
Authors: Havinga E. , den Hertog‐Polak M.
Published: September 2010

The calculation of the electric potential and the ionic concentrations in the neighhourhood of a monolayer containing fatty acids or other, partially ionized, organic acids is discussed in order to get a basis for the understanding of reaction rates in unimolecular layers. The systems tinder connsideration show several features allowing straightforward theoretical reasoning. It seems difficult however to reach a detailed description without further experimental study. Therefore a simplifying treatment using the well‐known Gouy‐Chapman method is deemed to he acceptable at this stage to serve as a lead in experimental research.
Properties and reactions of molecules at interfaces II. Chemical analysis of surface layers obtained by spreading a fatty acid on hypophases of varying ph and ionic composition)
Authors: Havinga E.
Published: September 2010

The analysis of stearic acid/stearate monolayers. spread on hypophases of varying concentrations of H+. Na−, Ca−+, Mg++., (Cu++), is described. A discussion of the results is given. Comparing them with the theoretical relations formulated in the preceding paper.
Influence of organic compounds on soap and phosphatide coacervates XVII): Preliminary notes on the action of disubstituted benzene derivatives on soap coacervates
Authors: Booij H. L.
Published: September 2010

The action of o‐, m‐, and p‐isomers of disubstituted benzene derivatives on soap coacervates depends inter alia on the interaction of the groups. With benzene derivatives with a hydrophilic “anchor” group and a hydro‐phobic second substituent we find the series p > m > o. When the second substituent is a chlorine atom the same series appears in some cases, in other cases (e.g. chloroanilines) the sequence is reversed. Then it appears that the second group possesses a more hydrophilic character. The “anchor” group is in this case an electron donor, while the chlorine atom is electron attracting. The action of other isomeric benzene derivatives may be explained from the same point of view.
Thermal quantities of some cycloparaffins. Part II purification of the samples)
Authors: Kaarsemaker Sj. , Coops J.
Published: September 2010

Purification of the cyclanes with 4 to 9 C‐atoms was effected by fractional distillation. Progress of the purification was checked with the aid of melting curves of the fractions (heat content vs. temperature curves of the melting process). The impurity content of the final samples is estimated at less than 0,2%. A fractionating column with a rotating cylinder and a small calorimeter for measurements on melting and transition processes at temperatures from — 180° to +70° are described.
Reactions of polypeptide esters in the solid state. I. Migration of methyl groups
Authors: Sluyterman L. A. Æ. , Veenendaal H. J.
Published: September 2010

When tetraglycine methyl ester is heated at 100° C a decrease in methoxyl content is observed, mainly after an induction period of about 200 hours. The reaction is virtually finished after 600 hours. Previous powdering of the ester crystals slightly reduces the induction period. The reaction product mainly consists of a mixture of tetraglycine, N‐methyl‐glycyl‐triglycine (sarcosyl‐triglycine) and N‐dimethylglycyl‐triglycine.

When alanyl‐triglycine methyl ester is heated at 100° C the induction period extends over several months.
Reaction products of primary β‐hydroxy‐amines with carbonyl compounds. I. The infrared absorption of acetals and ketals
Authors: Bergmann Ernst D. , Pinchas S.
Published: September 2010

The infrared absorption curves of 18 acetals and ketals have been measured in the region 1070–1190 cm−1.

The C—O—C band at 1130 cm−1 (ethers) is split in the case of acetals and ketals (C‐O‐C‐O‐C) into three branches: at 1158—1190 cm−1 at 1124—1143 cm−1 and at 1063—1098 cm−1. The molecular extinction coefficient of the last band is 2—5.104. A fourth band appears in the region 1038—1056 cm−1.

A tentative explanation of the observed effects is given.

Another characteristic band, at 1110 cm−1 appears only in the spectra of acetals, not in those of ketals, and may be related to a C—H deformation, perturbed by a neighbouring O—C bond.
Reaction products of primary β‐hydroxy‐amines with carbonyl compounds. VI. Oxazolidines derived from N‐phenylethanolamine
Authors: Zimkin Emanuel , Bergmann Ernst D.
Published: September 2010

N‐Phenylethanolamine condensed easily with aldehydes to give substituted oxazolidine. No reaction could be achieved with ketones.

The molecular refraction and the infrared and ultraviolet spectra of the substances were measured. Critical evaluation of the results shows, that in these compounds the molecular refraction can only be used with great caution as a tool in determining the structure.

The infrared spectra have been measured by Dr. S. Pinchas, the ultraviolet spectra by Dr. Y. Hirshberg, both of the Optics Department of this Institute.
Reactions of polypeptide esters in the solid state, II. A few cases of prevailing polycondensation. Remarks concerning the reaction mechanism
Authors: Sluyterman L. A. Æ. , Kooistra M.
Published: September 2010

When tetraglycine methyl ester is heated at 185° C in the solid state or at 100° C dissolved in methanol, polymers containing small amounts of sarcosyl‐units are formed. An induction period occurs only under the first mentioned conditions. Also polymers obtained by heating triglycine methyl ester at 100°–100° C partly consisted of sarcosyl‐units. Some of the phenomena described in this and the preceding part1) are believed to be due to rigidity of the crystal lattice.
Hammett's substitution constant for the methylsulphonyl group and its mesomeric effect. (Properties of the sulphonyl group XXIII)
Authors: Kloosterziel H. , Backer H. J.
Published: September 2010

Hammett's substitution constant σ for the methylsulphonyl group has been determined, giving σ‐meta‐CH3SO2 = 0.615 (0.6522) and two values for σ‐para‐CH3SO2 viz. + 1.15 for the substituted phenol and aniline and + 0.73 for the benzoic acid. This indicates that the methylsulphonyl group has a negative mesomeric effect and that its sulphur atom can extend the octet of electrons to a decet structure.
Preparation and constitution of some tert. Butyl‐acetylamino‐nitrobenzenes
Authors: Biekart H. J. B. , Dessens H. B. , Verkade P. E. , Wepster B. M.
Published: September 2010

The preparation and the determination of the constitution of six tert.butylacetylamino‐nitrobenzenes is described.
Hydrolyse du 9,9‐bis‐Méthylthio‐Thioxanthène‐10‐Dioxyde. (Propriétés du groupe sulfonyle XXV)
Authors: Kloosterziel H. , Backer H. J.
Published: September 2010

Le 9,9‐bis‐méthylthio‐thioxanthène‐10‐dioxyde (Ib), qui se forme par thiométhylation du thioxanthène‐10‐dioxyde (la), peut être regardé comme vinylogue des 1,1,1,1‐disulfuredisulfones.

L'hydrolyse acide engendre le thioxanthone‐10‐dioxyde (IV) et diffère done essentiellement de celle que subit le bis‐méthylthio‐bis‐méthylsulfonylméthane (II). L'hydrolyse alcaline, qui décroche un groupe méthylthio, est analogue pour les deux composés. En outre, l'action de la potasse alcoolique sur Ib donne un produit dimère (III).

L'oxydation au moyen d'acide perbenzoïque conduit à une trisulfone (Id), vinylogue des 1,1,1,1‐tétrasulfones inconnues.
Some remarks on the ionic radii of iron‐group elements. The influence of crystalline field
Authors: van Santen J. H. , van Wieringen J. S.
Published: September 2010

The ionic radii of iron group elements do not decrease monotonically from Ca towards Zn but show maxima at configurations d4, d5 and–possibly–d9, d10. An explanation is offered. It is based upon a heteropolar model where the influence of the other ions on the electronic distribution of 3d electrons is considered as a purely electrostatic influence of their net charges. The maxima are explained by the influence of a preponderantly cubic crystalline field, both for negliglible and strong interelectronic interaction.
Sodium salts of pectin and of carboxy methyl cellulose in aqueous sodium chloride. II Osmotic pressures
Authors: Pals D. T. F. , Hermans J. J.
Published: September 2010

The osmotic pressure of solutions of sodium pectinate and three samples of sodium carboxy methyl cellulose in aqueous solutions of sodium chloride were measured in a Fuoss and Mead osmometer. The primary aim was to obtain the molecular weights of the samples. As a by‐product the change of osmotic pressure with polymer concentration and salt content was studied.

The reduced osmotic pressure proves to be a linear functon of the polymer concentration. The slopes of the lines p/c versus c vary with the concentration of the sodium chloride in a manner which is in reasonable agreement with the predictions of the Donnan equilibrium. An accurate check is impossible because the activity coefficients are not known.
Sodium salts of pectin and of carboxy methyl cellulose in aqueous sodium chloride. III. Potentiometric titration
Authors: Pals D. T. F. , Hermans J. J.
Published: September 2010

The changes in pH in the titration of carboxy methyl cellulose or pectin are much larger than those derived from the molecular dimensions on the basis of current theories. The possible causes of this discrepancy are discussed.
The behaviour of membranes between electrolyte solutions III: The dissociation of carboxyl groups in cellulose
Authors: Hirsch P.
Published: September 2010

Former work (I and II) led to the conclusion that the membrane diffusion potential at cellulose membranes must be connected with the degree of dissociation of acid groups in the membrane. In this communication the dissociation of carboxyl groups in cellulose is investigated with the aid of “neutralization curves”.

Investigating cellulose material into which carboxyl groups had been introduced (oxycellulose), it appeared that the carboxyl groups occur in a reactive and an unreactive form, which are interconvertible. The unreactive carboxyl groups are assumed to be present in an anhydride form. If care is taken that the carboxyl groups are present in the reactive form, they can be titrated, and well‐defined neutralization curves can be obtained. Neutral salts greatly influence the titrations. Shape and position of the neutralization curves depend on the content of carboxyl groups in the material. — The law of mass action and the Donnan equilibrium as commonly formulated are not sufficient to explain shape and position of the neutralization curves, nor is it clear in what way they are connected with the membrane diffusion potentials.
Steric effects on mesomerism: VII. Deacylation of a number of acetylamino‐nitronaphthalenes and some of their derivatives
Authors: Krol L. H. , Verkade P. E. , Wepster B. M.
Published: September 2010

This paper contains data on the (pseudo) catalytic deacylation of 1‐ and 2‐acetylaminonaphthalene, five homonuclear acetylamino‐mononitronaphthalenes (including the 2,3‐isomer), five heteronuclear acetylaminomononitronaphthalenes, and some other acetylaminonaphthalene derivatives in an alkaline medium. The rates of deacylation are discussed in some detail, mainly on the basis of the peculiar electronic properties of the naphthalene nucleus, and from the point of view of the theory of steric effects on mesomerism.
Preparation et analyse thermogravimetrique des dithizonates d'argent, de plomb, de zinc et de cuivre
Authors: Pariaud Jean‐Charles , Archinard Pierre
Published: September 2010

La recherche de la solubilité des métaux dans l'eau

J. C. Pariaud et P. Archinard, Sur la solubilité des métaux dans l'eau. Bull, soc. chim. Mémoire no. 33 ( 1952 ) à paraitre.

nous a conduit à utiliser la dithizone comme réactif d'analyse. En liaison avec cette étude nous avons isolé et étudié le comportement à la chaleur des dithizonates d'Ag, de Pb, de Zn et de Cu.
Vanillic acid — a new reagent for thorium
Authors: Krishnamurty K. V. S. , Purushottam A.
Published: September 2010

Vanillic acid precipitates thorium quantitatively from solutions of pH 3.6 and about. The presence of a number of elements like calcium, strontium, barium, magnesium, zinc, cadmium, nickel, cobalt, beryllium, aluminium and the rare earths causes no interference. The precipitate on washing may be ignited and weighed as oxide. Thorium in monarite may be conveniently estimated in a single precipitation in this way.
Reactivity of 4‐nitropyridine‐N‐oxide (II)): Substitution of the nitro‐group by hydroxyl)
Authors: den Hertog H. J. , Combé W. P.
Published: September 2010

Whereas 4‐nitropyridine‐N‐oxide is very stable towards dilute solutions of acids in water, its nitro‐group can be replaced by hydroxyl in a quick reaction by treating this substance with an alkaline solution of hydrogen peroxide in water at a temperature not surpassing 50°. This remarkable substitution reaction proceeds also when other 4‐substituted derivatives of pyridine‐N‐oxide and 4‐nitropyridine are reacted with the same reagent.
A new synthesis of aryl‐aliphatic alcohols. V. The structure of the compound C19H18O
Authors: van Essen H. , Beets M. G. J.
Published: September 2010

Conclusive evidence is presented for the structure of the compound C19H18O, obtained as a by‐product in the reaction of indene with formaldehyde.
Kinetical experiments on ozonization reactions. III. The ozonization velocities of some benzene derivatives )
Authors: Wibaut J. P. , Sixma F. L. J.
Published: September 2010

The velocities of the reactions of ozone with a number of benzene derivatives were measured.

The reactivity in various series of benzene derivatives proceeds as follows:

magnified image

Isopropyl benzene reacts abnormally rapidly with ozone; it is probable that here, in addition to disruption of the benzene nucleus, other reactions take place; secondary butyl benzene does not show this different behaviour.

Anisole reacts very rapidly with ozone so as to form a triozonide. The formation of a triozonide was also demonstrated with regard to o‐xylene and chlorobenzene.

These results confirm the similarity in mechanism between the addition of ozone and the electrophilic substitution reactions, established on an earlier occasion

Part I: H. Boer and F. L. J. Sixma, Rec. trav. chim. 70, 997 (1951); Part II: F. L. J. Sixma, H. Boer and J. P. Wibaut, Rec. trav. chim. 70, 1005 (1951).

.
The preparation of pyridine derivatives from halogenopyridines by means of the grignard reaction V. Application of the reaction to 3‐bromopyridine
Authors: Wibaut J. P. , van der Voort H. G. P.
Published: September 2010

Improved directions are given for the preparation of an ethereal solution of 3‐pyridylmagnesium bromide. Starting from this compound, the following pyridine derivatives are prepared: 1‐(pyridyl‐3)‐heptene‐1, methyl‐(pyridyl‐3)‐ketone, (pyridyl‐3)‐methanal acetal, 3‐(pyridyl‐3)‐propene, and 3‐isobutenyl pyridine. By the oxidation of the latter substance, (pyridyl‐3)‐acetone is obtained.
Molecular complexes of iodine with olefinic compounds
Authors: Ketelaar J. A. A. , van De Stolpe C.
Published: September 2010

From U.V. absorption spectra the equilibrium constants were determined for the formation of complexes of iodine with diisobutylene, (CH3)2C = CHC(CH3)3: Kx = 3.7; cis‐dichloroethane, Kx = 0.25; trichloroethene, Kx = 0.19 and tetrachloroethene, Kx = 0.11, as active components in n‐hexane as a solvent. The relation of the tendency towards association with the double bond character is stressed.
The reaction between urea and formaldehyde in concentrated solutions
Authors: de Jong J. I. , de Jonge J.
Published: September 2010

The nature and the velocities of the reactions occurring in concentrated solutions of urea and formaldehyde may be very similar to what is found in dilute systems.

A rapid initial reaction between urea and formaldehyde, as reported in literature, was not observed and is shown to be due to the analytical methods used.
Photodecomposition of aqueous solutions of diazonium salts in the presence of mercurous ions
Authors: Bos J. G. , Alink R. J. H. , Dippel C. J.
Published: September 2010

Photodecomposition of aqueous solutions of o‐hydroxydiazonium salts leads todisproportionationof mercurous ions, in contrast to p‐amino‐benzenediazonium salts where mercury results fromreductionof mercurous ions by the photodecomposition products.
Studies in alums. II. Manganic and cobaltic alums
Authors: Zernike J.
Published: September 2010

Preparation of Cs—Mn alum and mixed crystals of NH4—Mn—Al alum. Determination of their magnetic susceptibilities.

Preparation of Rb—Co alum, its mixed crystals with Rb–Al alum, and mixed crystals of NH4—Co—Al and K—Co—Al alums. These are all diamagnetic.
Titration of adsorbed acids V
Authors: Mans A. E. , Vervelde G. J.
Published: September 2010

The effect of adding activated charcoal to solutions of relatively strong organic acids on the shape of the titration curves is examined theoretically. Titration curves were calculated on the basis of the assumption that the uneven distribution of the acids, due to the presence of the adsorbent, can be described as a two‐space distribution, one of the spaces containing the acids in the adsorbed state, the other containing the unadsorbed remainder of the acids and at the same time determining the potential of the hydrogen electrode. The ionic compositions of the solutions in both spaces are supposed to be interrelated in accordance with the rules of the Donnan distribution. The calculated curves show features quite similar to those obtained experimentally. Especially the remarkable influence of the valency of the base used for the titration could be explained satisfactorily.
The structure of the reaction product of ϵ‐caprolactam and phthalic anhydride
Authors: van der Want G. M.
Published: September 2010

The reaction product of ϵ‐caprolactam and phthalic anhydride is compared with that of ϵ‐aminocaproic acid and phthalic anhydride. The two are identical, and the structure can be designated as ϵ‐phtalimidocaproic acid.
Caractérisation des Amines au Moyen des Quinones Halogénées
Authors: Buu‐Hoï N. P. , Royer René , Eckert Bernard
Published: September 2010

Il est montré que les quinones halogénées telles que la chloranile et surtout la 2,3‐dichloro‐1,4‐naphtoquinone peuvent être utilisées avantageusement pour caractériser les amines primaires et secondaires. De nombreuses aminoquinones nouvelles ont été préparées à cette fin, et certaines d'entre elles ont en outre un interét soit au point de vue biologique, soit au point de vue tinctorial.
Réaction du Chlorure Trichlorométhane‐Sulfénique sur les Mercaptannes
Authors: Backer H. J. , Westerhuis E.
Published: September 2010

Le chlorure trichlorométhanesulfénique réagit aisément sur les thioalcools et thiophénols en produisant avec un bon rendement des esters trichlorométhanesulféniques (alcoyl‐ et aryl‐trichlorométhyl‐disulfures). Sauf quelques esters aromatiques cristallisés, ces produits sont des huiles lourdes.
Réaction du Chlorure Trichlorométhane‐Sulf́enique sur les Thioalcoolates et Thioph́enolates
Authors: Backer H. J. , Westerhuis E.
Published: September 2010

La réaction de CCl3SCl sur un mercaptide aliphatique donne naissance a un hexa‐alcoylthio‐diméthyldisulfure et à un dialcoyldisulfure simple.

La réaction sur un thiophénolate produit, outre un disulfure, un hexa‐arylthio‐diméthyl‐tri‐sulfure. L'oxydation de ces derniers composés conduit à des esters de l'acide trithiopercarbonique.
The polarographic reduction of conjugated hydrocarbons. I. A theoretical discussion of the polarographic reduction of aromatic hydrocarbons
Authors: Hoijtink G. J. , van Schooten J.
Published: September 2010

A theoretical discussion has been given of the linear relation between the half‐wave reduction potential ε1/2 of aromatic hydrocarbons and the root a of the zero order molecular orbital secular equation corresponding to the lowest non‐occupied π‐electronic level of the molecule, which can be represented by the formula:

The magnitude of the zero order “exchange” parameter γ = −2.25 ± 0.07 e.v. has been obtained by substituting the reduction potentials of some aromatic compounds in the given formula.

The course of the reduction process can be qualitatively predicted by considering the π‐electronic distribution in the intermediate molecule ion and radical ion, the probability for the addition of the proton being largest at the carbon atom with the highest negative charge.
Spectrophotometric study of the solvation of iodine in dioxan solution II
Authors: Ketelaar J. A. A. , van de Stolpe C. , Goudsmit A. , Dzcubas W.
Published: September 2010

The solvation of iodine in dioxan‐carbon tetrachloride and dioxan‐n‐hexane solutions was studied by measuring the absorption spectra at different concentrations and temperatures. The concentration of the iodine‐dioxan complex is derived both from the extinction at about 4525 Å and at 2650 Å. The equilibrium constants thus derived from two independent series of measurements were found to correspond within the limits of accuracy, thus proving that both the absorption in the visible and in the ultraviolet part has to be ascribed to the same iodine‐dioxan complex 1:1.

The equilibrium constant Kx at 25° C was found to be 9.1 and 9.3 for carbon tetrachloride and n‐hexane solutions respectively. From the dependance on temperature the heat of formation was found to be 3300 ± 200 cal/mole and 3500° 200 cal/mole respectively.
The interaction of free radicals and aromatics. I. Reaction of anthracene and of pyrene with 2‐cyano‐2‐propyl radicals
Authors: Bickel A. F. , Kooyman E. C.
Published: September 2010

2‐Cyano‐2‐propyl radicals (R) generated by decomposition of 2,2′‐azo‐isobutyronitrile were found to add on to anthracene (A) at one of the reactive 9,10 positions, yielding radicals R—A with a free valence at the other meso‐position. The latter combine to a dimer (R—A—A—R) in 22.5% yield and, with R, form cis and trans R—A—R in 49% and 13.5% yield. Under the same conditions, pyrene gave little reaction.

Thermal decomposition of both R—A—A—R and R—A—R produces anthracene and 2‐cyano‐2‐propyl radicals in high yields, while H—A—A—H (9,9′,10,10′‐tetrahydrodianthranyl‐9,9′) gives anthracene and 9,10‐dihydroanthracene.

The significance of these results relative to the formation of substitution products from aromatics and highly reactive radicals is discussed.
Steric effects on mesomerism VIII : Benzoquinuclidine, an aromatic amine without mesomeric interaction between the benzene ring and the amino group
Authors: Wepster B. M.
Published: September 2010

The spatial configuration of benzoquinuclidine (I) is such as to justify on theoretical grounds the assumption that the mesomeric interaction between the amino group and the benzene ring is at a minimum. The experimental work reported here proves that this interaction is in fact essentially zero, and hence that, in general, elimination of mesomerism by steric factors is possible. This result was obtained by a study of ultraviolet absorption spectra and of the ability to couple with diazonium compounds.
Steric effects on mesomerism IX : The basic strength of benzoquinuclidine and its bearing on the basic strength and the mesomeric energy of aromatic amines
Authors: Wepster B. M.
Published: September 2010

In this paper it is shown that the low basic strength of aromatic amines as compared with aliphatic amines is equally due to the inductive and the mesomeric effect; each of these is responsible for a decrease of about three pKa units. On this basis the (extra) mesomeric energy of aromatic amines is calculated as 4 kcal/mol.
The synthesis of 4‐hydroxy‐6‐amino‐isophthalic acid and related compounds: Chemotherapy of tuberculosis II
Authors: Beyerman H. C. , Wielaert G. L. G.
Published: September 2010

In connection with the tuberculostatic and pharmacological properties of 4‐hydroxy‐6‐amino‐isophthalic acid (4‐hydroxy‐6‐aminobenzene‐1,3‐dicarboxylic acid) a synthesis with 4,6‐dinitro‐m‐xylene (1,3‐dimethyl‐4,6‐dinitrobenzene) as starting material is described. Other alternate routes are discussed.

A convenient procedure for preparing 4,6‐dinitro‐m‐xylene from technical grade xylene is given.
Sur la Chimie du Sec.‐Dodécylbenzène
Authors: Buu‐Hoï Ng. Ph. , Royer R. , Bizzini B.
Published: September 2010

Dans ce travail, on dêcrit un certain nombre de dérivés du sec.‐dodecylbenzène ‐ (1′ ‐ méthyl ‐ undécylbenzène) (cétones, hydrocarbures, dérivés azotés), préparés au cours d'une étude sur la réactivité de cet hydrocarbure aromatique.
Structure of α,ω‐diphenylpolyenes.: I. crystal data of 1,4‐diphenyl‐1,3‐butadiene, 1,6‐diphenyl‐1,3,5‐hexatriene and 1,8‐diphenyl‐1,3,5,7‐octatetraene
Authors: Drenth W. , Wiebenga E. H.
Published: September 2010

1,4‐Diphenyl‐1,3‐butadiene, 1,6‐diphenyl‐1,3,5‐hexatriene and 1,8‐diphenyl‐1,3,5,7‐octatetraene have each both a monoclinic and an orthorhombic modification of which lattice constants and some optical data are given.
Influence of the solvent on the action of ammonia on halogeno‐derivatives of pyridine and nitrobenzene
Authors: Den Hertog H. J. , Jouwersma C.
Published: September 2010

The reactivity of 2,4,6‐tribromopyridine‐towards dilute solutions of ammonia in water and butanol is described. The rate of the substitution reaction is higher in water than in the less polar butanol. In water the reagent attacks chiefly the bromine atom at the 4‐position, where the nucleus carries the highest positive electrical charge. In butanol the replacement of the bromine atoms at the 2‐ and 6‐positions is preponderant. Together with 2‐amino‐4,6‐dibromopyridine and 4‐amino‐2,6‐dibromopyridine, which compounds were known, 2,4‐diamino‐6‐bromopyridine was isolated as a reaction product.

In agreement with the above‐mentioned results 2,4‐dichloronitrobenzene reacts more quickly with ammonia in water than in ethanol. While in the latter solvent during a reaction at 140° exclusively the ortho chlorine atom is replaced, in water, in addition to 2‐amino‐4‐chloronitrobenzene, some 4‐amino‐2‐chloronitrobenzene is formed.
The relation between the stability of metal complexes in solution and the ionization potential of their metal component
Authors: van Panthaleon Van Eck C. L.
Published: September 2010

The relation between the stability (log k) of a metal complex in solution and the ionization potential (I) of the metal component is ascertained for a number of systems described in the literature. There proves to be a linear relation of the following form: log k = p. (I − q). The value of q is found to depend on the functional group(s) of the ligand, that of p on the number of the functional groups in the ligand and the polarizability of the ligand molecule.
The Raman spectrum of liquid and solid gallium trichloride
Authors: Gerding H. , Haring H. G. , Renes P. A.
Published: September 2010

The Raman spectra of solid and liquid gallium trichloride are communicated. From the number of frequency shifts found and from the frequency values it is probable that gallium trichloride is present as double molecules Ga2Cl6 in the solid and in the liquid. The structure of these double molecules is probably that of the ethylenic (bridge) model as was formerly concluded for Al2Cl6 etc., although the absence of polarization measurements makes this conclusion less conclusive. The result is in agreement with the crystal structure determination of Ga2Cl6 as given in the Thesis of Renes. A comparison is made between experimental and calculated frequency values for the “ethane” and the “ethylenic” models.
On electro‐osmosis and streaming‐potentials in diaphragms: III. Electrokinetic effects in networks of capillaries
Authors: Overbeek J. Th. G. , van Est W. T.
Published: September 2010

Elektrokinetic effects in diaphragms are treated with the aid of a model consisting of a network of capillaries. With negligible surface conductance or when all capillaries have equal cross‐sections the streaming‐potential E/P and the electro osmotic flow V/I are both equal to ϵζ/4πη. R. C where R and C are the resistance and the capacity of conductance of the network. In the presence of surface conductance, and for unequal cross‐sections of the capillaries, the proportionality constant between E/P or V/I and RC may be either smaller or greater than ϵζ/4πη depending on the detailed structure of the diaphragm. The first case is the usual one. For a value larger than ϵζ/4πη rather exceptional conditions have to be fulfilled.
Sulfones DI‐α‐Oléfiniques: (Propriétés du groupe sulfonyle XXXII)
Authors: Backer H. J.
Published: September 2010

En faisant réagir des aldéhydes sur l'acide sulfonyldiacétique et sur ses esters en présence d'acétate de pipéridine, on parvient à obtenir des sulfones di‐α‐oléfiniques. Celles‐ci sont à même de fixer sur leurs doubles liaisons des réactifs nucléophiles.
Kinetics of the reaction between mono‐methylolurea and methylene diurea
Authors: de Jong J. I. , de Jonge J.
Published: September 2010

The reaction between monomethylolurea and methylene diurea appeared to be bimolecular and the rate constants were found to be directly proportional to the concentration of the hydrogen ions. An influence of the buffer concentration was not observed. The activation energy was found to be 15 kcal/mol.
Etude physico‐chimique de la vagotonine: II. Ultracentrifugation
Authors: Michel G. F.
Published: September 2010

Nos premiers essais de fractionnement de la vagotonine isolée du pancréas par Santenoise1) nous ont amenés à séparer par précipitation fractionnée au sulfate de lithium deux fractions de solubilités différentes 2). Nous avons par la suite fractionné de nouveau la portion la plus soluble, et dans une précédente communication 3), nous avons décrit leur comportement électrophorétique. Ces substances se sont révélées non homogènes à L'électrophorèse et renferment trois composés principaux accompagnés d'autres protéines en proportions plus faibles. Nous avons voulu vérifier si cette hétérogénéité se manifestait également lors de la sédimentation à L'ultracentrifugeuse.
Stability of oil‐in‐water emulsions II: Mechanism of the coagulation of an emulsion
Authors: van den Tempel M.
Published: September 2010

The colloidal stability of an oil‐in‐water emulsion can be correlated with the well‐known behaviour of the hydrophobic sols of solid particles if the rate of coagulation is expressed in terms of a decrease in particle concentration.

Coagulation of an emulsion occurs in two stages, called flocculation and coalescence. Flocculation is assumed to occur according to the second order reaction process applied by Von Smoluchowski to the similar phenomenon in the hydrophobic sols of solid particles. Coalescence is a first order reaction and will only occur between adjacent drops in an aggregate.

An equation is derived in which the particle concentration is expressed as a function of both the rate of flocculation and the rate of coalescence, and the time of coagulation. The rate of coagulation appears to depend upon the particle concentration, in such a way that the rate of increase of 1/n increases with decreasing initial particle concentration. Approximations are given which may be applied to cases of practical importance.