bluuebunny/crossref_metadata_2025 huggingface dataset:
Complexresonance. Preliminary communication
Authors: Brackman W.
Published: September 2010

The colour effects, which occur in the liquid phase in mixtures of quinones or nitro compounds on the one hand and unsaturated or aromatic compounds on the other, are attributed to complexresonance. By this is understood a covalent binding between two molecules, the character of which lies in between that of a single bond and no bond at all.

A summary is given of the two types of substances which can exhibit complexresonance with each other and of the phenomena which are associated with complexresonance.

Complexresonance is considered as the cause of a number of cases of quenching of fluorescence. In addition it is considered of importance for the formation of the activated complex of certain reactions and for the explanation of some types of enzymatic reactions.
La Réaction Entre L'orthoformiate D'éthyle et les Amines Aromatiques Primaires
Authors: Backer H. J. , Wanmaker W. L.
Published: September 2010

La réaction des amines aromatiques primaires sur l'orthoformiate d'éthyle ne donne pas les orthoformamides HC(NHR)3, mais les formamidines RN : CH.NHR. La réaction entre l'aniline et l'acétate de diéthoxyméthyle conduit également à une amidine.

Tous les composés décrits dans la littérature comme orthoformamides d'amines primaires sont des amidines.
2‐Thiobenzaminonaphthalene: Discrepancies in the literature VII
Authors: van Alphen J. , Drost G.
Published: September 2010

The melting point of 2‐thiobenzaminonaphthalene is 164°. When 1 mol. 2‐aminonaphthalene, 1 mol. benzaldehyde, and 1 at. sulphur are heated at 170–180°, not 2‐thiobenzaminonaphthalene, but 2‐phenyl‐naphtho‐2′,1′: 4,5‐thiazole is obtained.
Some naphthindazolquinones with antibacterial properties
Authors: Spruit C. J. P.
Published: September 2010

Some derivatives of lin‐naphthindazol‐4,9‐quinone possess antibiotic properties which are intimately connected with chemical structure.
Absorption spectra of quinones. II. Anthraquinones and heterocyclic analogues
Authors: Spruit C. J. P.
Published: September 2010

It has been shown with a number of examples that, as an approximation, the absorption spectra of derivatives of anthraquinone may be obtained by adding the absorption spectra of the naphthoquinones corresponding to the two halves of the anthraquinone molecule. The deviations from strict additivity are discussed. The spectra of derivatives of lin. naphthindazolquinone are remarkably similar to those of the analogous anthraquinones. This is a new example of the aromatic properties of the pyrazole nucleus.
2‐Methylbuten‐3‐yl 2‐methyl ether and 2‐methylbuten‐2‐yl 4‐methyl ether
Authors: Ultée A. J.
Published: September 2010

The ether obtained by Supniewsky1) by the action of calcium cyanamide and potash on isoprene hydrobromide in methyl alcoholic solution, does not possess the structure (CH3)2C:CH. CH2OCH3, given by this investigator, but is (CH3)2. C(OCH3). CH:CH2. Both ethers have been prepared.
Studies in filtration: Part I
Authors: Heertjes P. M. , Haas H. V. D.
Published: September 2010

In this paper a study is given about the initial stages of filtration at constant pressure from which conclusions could be drawn about the interrelation between cloth and cake.

It was found that ‐ with one system ‐ two types of filtration may occur, blocking filtration and cake filtration, depending on the concentration of the solid substance in the prefilt: By increasing this concentration blocking gradually decreases and finally blocking filtration changes to cake filtration.

With cake filtration at constant pressure the specific resistance of the cake depends on the concentration in the prefilt; decreasing with increasing concentration.

An equation for complete blocking filtration has been derived.
Direct observation of variations in electrode potentials by means of the Cathode‐Ray oscillograph
Authors: Lebbink F. J. , Weydema J. , Burgers W. G.
Published: September 2010

The rapid variations in potential of the electrodes in an electrolytic cell when closing or interrupting the current were made visible on the screen of a cathode‐ray oscillograph as a repeating image. This was achieved by using a periodically interrupted current, obtained by means of an electronic interruptor.

Indication of time was realized by means of a periodic suppression of the cathode ray.

A particular feature of the measuring equipment is the possibility of complete synchronisation of its different parts.
Synthesis of polychloro compounds with aluminium chloride VIII. Decachlorohexadiene‐1,5, its isomerisation, cyclisation and cleavage
Authors: Prins H. J.
Published: September 2010

The present paper describes the action of dechlorination agents upon hexachloropropene the preparation of decachlorohexadiene‐1,5, of a liquid isomer, probably decachlorohexadiene‐2,4, the cleavage and the cyclisation of both compounds. The compound obtained by cyclisation, a decachloromethylcyclopentene, can be cleaved into carbon tetrachloride and hexachlorocyclopentadiene.
Derivatives of 2,4‐dichlorophenoxyacetic hydrazide
Authors: Chao Janice Chung‐Chin , Sah Peter P. T. , Oneto John F.
Published: September 2010

Ethyl ester of 2,4‐D (2,4‐dichlorophenxyacetic acid) (I), colorless liquid, b.p. 149‐155° at 5 mm, was prepared with good yield by allowing the acid to react with thionyl chloride and then decomposing the acid chloride with absolute ethyl alcohol.

80 g of (I) reacted with 20.4 g of 85% hydrazine hydrate in 10 cm3 absolute ethyl alcohol gave 75.1 g of hydarzide (II), colorless needles from 95% ethyl alcohol, m.p. 155‐157°.

II in 95% ethanol condensed with aldehydes and ketones formed crystalline hydrazones. Twenty‐one hydrazone derivatives were prepared for plant growth studies.
A new synthesis of benzo (b) thiophanthrene
Authors: Werner E. G. G.
Published: September 2010

When heated, the compound obtained by benzoylation of 3‐methyl‐benzo‐thiophene forms benzo (b) thiophanthrene (Elbs reaction). This proves that this benzoylation has resulted in the formation of the 2‐benzoyl‐3‐methyl benzothiophene.

The benzo (b) thiophanthrene was also synthesized by starting from dibenzothiophene.

Ultraviolet absorption spectra were measured.
L'Action de L'Acide Chlorhydrique Gazeux sur la Cyanhydrine Acetonique
Authors: Ultée A. J.
Published: September 2010

Dans une communication provisoire

Ce Recueil28, 349 (1909).

, il a été démontré que du produit obtenu par l'action de l'acide chlorhydrique gazeux sec sur la cyanhydrine acétonique et addition subséquente d'un égal volume d'eau, deux composés peuvent être isolés: le chlorhydrate d'une base C8H14O2N2, contenant une molécule d'eau de cristallisation, et un produit C12H19O5N.

On donne maintenant la preuve que la base est un imino‐éther, le (1‐méthyl‐1‐cyano‐éthyl) (2‐méthyl‐1‐imino‐2‐hydroxypropyl) éther (chlorhydrate I), tandis que, pour le deuxiéme produit, la formule III (3,3,6,6,8,8‐hexaméthyl‐(1‐aza‐4,7‐dioxa‐cyclo‐nonatrione‐2,5,9)) semble très vraisemblable.
A new method of preparing glycollide
Authors: Sporzyński A. , Kocay W. , Briscoe H. V. A.
Published: September 2010

The thermal decomposition of sodium chloracetate under reduced pressure in the presence of copper gave glycollide with a yield exceeding 70%. Other salts of chloracetic acid can be used with equally good results. Metals other than copper gave inferior results. Glycollide serves as a convenient starting material for the preparation of glycollic acid and its esters.
Researches on the alkoxy‐amino‐nitrobenzenes: VI. A survey of their anaesthetic properties
Authors: Verkade P. E. , van Dijk C. P. , Witjens P. H.
Published: September 2010

The anaesthetic properties of a number of alkoxy‐amino‐nitrobenzenes belonging to all ten possible types have been studied with the aid of three different methods: the rabbit cornea test, the frog muscle sciatic nerve test and the goldfish test. The data obtained thus relate to surface anaesthesia, block anaesthesia and general (central) anaesthesia. These data are discussed from a purely chemical point of view. The pharmacological part of the work and a discussion of the data from a pharmacological point of view will be published elsewhere.
A method for the accurate calculation of some thermodynamic properties of non‐polar or moderately polar substances, based on Van Laar's theory
Authors: Heukelom W.
Published: September 2010

Van Laar's method to calculate the critical conditions is based on the molecular constants a and b in van der Waals' equation of state. In certain cases inaccuracies in the calculated values of a may lead to results which deviate considerably from the experiment. In the present article it is demonstrated that the accuracy may be increased to a considerable extent by replacing the constant a in the calculations by less fundamental magnitudes, such as the boiling point and the vapour tension factor. It is found that in the latter case the probable error is of the same order of magnitude as the experimental error. An extensive survey is given of the results for several substances of different structural types. A brief survey is given of some further data which can be calculated from the results obtained.
On the sweet taste of 1‐n‐propyl‐2‐amino‐4‐nitrobenzene
Authors: Blanksma J. J.
Published: September 2010

The 1‐alkyl‐2‐amino‐4‐nitrobenzenes are sweet in taste. 1‐Methyl‐2‐amino‐4‐nitrobenzene is 330 times as sweet as cane sugar, 1‐n‐propyl‐2‐amino‐4‐nitrobenzene, which has now been investigated is 2000 times as sweet as cane sugar. 1‐Methyl and 1‐n‐propyl‐2‐nitro‐4‐aminobenzene are tasteless. The acetyl derivatives of all of these compounds are tasteless.
A method for the detection of amphoteric substances in paper chromatography
Authors: Sluyterman L. A. Æ. , Veenendaal H. J.
Published: September 2010

Paper chromatograms are treated with a solution of tropaeolin 00, dried and held in hydrochloric acid vapour. Amphoteric substances appear as yellow spots on a red background.
Mechanism of reinforcement III: Viscosity of carbon black suspensions in GR‐S solutions
Authors: Amborski Leonard E. , Goldfinger George
Published: September 2010

The viscosity of carbon black suspended in GR‐S solutions has been investigated in a Stormer‐type viscosimeter at various rates of shear. Relative viscosities thus determined have been extrapolated to zero rate of shear and by applying Einstein's viscosity equation the volume of the suspended particles has been calculated. It has been found that under the conditions examined the carbon black particles are surrounded by a rubber layer 150 to 200 Ängstroms thick.
Inhibition. Induction and the chain‐reaction theory. IV: Catalysis and the periodic system. I
Authors: Jorissen W. P.
Published: September 2010

An investigation of the relations between Catalysis and the Periodic System will prove to be of value for the development of both.
Substitution Centrale Dans le Tris‐Méthylsulfonyl‐Méthane (Les Propriétés du Groupe Sulfonyle VI)
Authors: Backer H. J.
Published: September 2010

L'hydrogène lié à l'atome central de carbone du tris‐méthylsulfonyl‐méthane peut être substitué par des métaux, le chlore. le brome, le méthyle, les thioaryles et même par le groupe nitro. Plusieurs produits de substitution qui sont difficilement ou pas du tout accessibles par voie directe se laissent obtenir en suivant un détour, par oxydation de composés qui n'ont que deux groupes CH3SO2, à cǒté d'un groupe CH3S. Ces composés substitués et partiellement oxydés XC(SCH3) (SO2CH3)2 peuvent étre obtenus selon deux méthodes: introduction finale soit de X, soit de SCH3.

Enfin les substitutions réalisées sont examinées au point de vue de la théorie électronique. Elles se rangent toutes parmi les substitutions électrophiles.
Hydrolyse des Produits Obtenus par Substitution Centrale du Tris‐Méthylsulfonyl‐Méthane (les Propriétés du Groupe Sulfonyle VII)
Authors: Backer H. J.
Published: September 2010

Les dérivés quaternaires du tris‐méthylsulfonyl‐méthane XC(SO2CH3)3 sont hydrolysés en solution alcaline. Souvent l'hydrolyse s'accomplit à froid déjà. Au cas où le groupe substituant X est CH3, C6H5, C6H5S, CH3C6H4S ou NO2, un groupe ‐SO2CH3 est expulsé sous forme d'acide méthane‐sulfonique. L'hydrolyse de la nitrotrisulfone O2NC (SO2CH3)3 donne naissance à la nitrodisulfone O2NCH (SO2CH3)2, que l'on identifie aisément sous la forme de sels ou du dérivé bromé O2NCBr(SO2CH3)2.
Oxidative phenomena in dilute solutions of substances with a system of conjugated double bonds. II. Alkali‐isomerized linoleic acid
Authors: Groot E. H. , Monnikendam Ph.
Published: September 2010

Abnormal spectra with absorption maxima at 310‐, 273‐ and below 225 mμ are sometimes obtained in very dilute solutions of alkali‐isomerized linoleic acid in various solvents. In all probability these anomalies are connected with the occurrence of autoxidative processes in the solutions.
The bromination of naphthalene IV.): A theoretical treatment of the influence of the temperature on the proportions of α‐ and β‐bromonaphthalene formed below 300°
Authors: Sixma F. L. J.
Published: September 2010

A theoretical treatment is given of the non‐catalytic bromination of naphthalene. In the bromination of liquid naphthalene in the temperature range from 85° to 215° and in the bromination of gaseous naphthalene in the presence of a non‐specific contact material (pumice or glass wool) below 300° the ratio of β‐bromonaphthalene to α‐bromonaphthalene is determined by the difference in activation energies of the simultaneous reactions. This difference in activation energies is calculated by means of approximate methods elaborated in wave mechanics.
A new synthesis of ω‐amino‐p‐hydroxyacetophenones and their reduction to the corresponding aminoethanols
Authors: Asscher M.
Published: September 2010

A new synthesis is described of compounds of the type

magnified image

by the condensation of phenol or its derivatives with aminoacetonitriles according to the method of Hoesch and Houben. The corresponding alcohols are prepared by catalytic reduction of the ketones obtained.
Étude Cinétique de la Polycondensation de L'acide Amino‐II Undécanoïque
Authors: Champetier G. , Vergoz R.
Published: September 2010

L'étude cinétique de la polycondensation à l'état fondu d'un aminoacide particulier, l'acide amino‐II undécanoique, conduit à admettre que la réaction est du second ordre, mais que la constante de vitesse est fonction du temps et représentée convenablement par l'expression k = k0 exp (‐ αt).

Si t est exprimé en secondes, k0 = 5.2 et α = 1.775 × 10−4.
On the range of existence of the liquid state
Authors: Zernike J.
Published: September 2010

The contention sometimes met with that the ratio of critical and triple point temperature is about constant for different substances, is shown to be erroneous. It actually may have values from 1.07 to 12.3. Though some compounds, usually classed as one group, show about the same value for this ratio, other related compounds have largely different values. As a first approximation a linear relation is found between this ratio and the logarithm of the triple point pressure. On the strength of this relation it is suggested that when the vapour pressure of a solid has been measured to about 120 at no reversible melting is to be expected. Reasons are advanced that mercuric sulphide and paracyanogen may be cases in point.
Étude D'une Fraction de Polystyrène dans des Solvants Composés
Authors: Vallet G.
Published: September 2010

The viscosity of solutions of a fractionated polystyrene in various toluene‐butanol mixtures, and the diffusion velocity of the polystyrene in these solutions are determined.

The results obtained are discussed in the light of current theories.
The preparation of some amino‐1,4‐Benzodioxanes and AZO dyes derived therefrom
Authors: Heertjes P. M. , Revallier L. J.
Published: September 2010

In this paper an improved method for the preparation of 6‐nitro‐1,4‐benzodioxane, the preparation of 6‐amino‐7‐nitro‐1,4‐benzodioxane and of 6‐amino‐1,4‐benzodioxane‐sulphonic acid is described.

Some azo dyes derived from the last two substances, showing moderate to good properties, are given.
The degradation of lupeol derivatives to C27‐ketones
Authors: Davy G. S. , Jones E. R. H. , Halsall T. G.
Published: September 2010

The degradation of α‐lupene to trisnorlupanone has been re‐examined and analogous reactions with lupenyl acetate have yielded the corresponding C27 keto‐acetate. Conclusive evidence of the presence of a carbonyl group in these compounds has been obtained by spectrographic methods and by lithium aluminium hydride reduction.
Spectres D'absorption Infrarouges de Trichloracrylates Métalliques
Authors: Duval Cl. , Gerding H. , Lecomte J.
Published: September 2010

Nous avons examiné, pour la première fois, entre 1600 et 700 cm−1 environ, les spectres d'absorption de six sels métalliques de l'acide trichloracrylique, ainsi que cet acide lui‐même. La technique habituelle, correspondant à l'étude des substances en poudre, s'est appliquée sans aucune difficulté

Sur la technique générale: J. Lecomte et P. Lambert, Ann. office natl. combustibles liquides 6, p. 1001 (1932); Ann. phys. [X] 18, 329 (1932); ibid. [XI] 10, 503 (1938); Publs, sci. et tech. ministère air France No. 34, 1933 et 142, 1939. Sur la méthode des poudres, en général: J. Lecomte, Cahiers de physique, 1943, No. 17, p. 1.

). II faut noter cependant que la dispersion du spectrographe étant faible entre 1200 et 1600 cm−1, les positions des bandes situées dans cette région ne sont données qu'à titre indicatif.
Recherches sur les Composés à Deux Cycles Pyridiques: Bis‐pyridiniums, bis‐pyridones‐2, bis‐piperidones‐2 et leur dérivés
Authors: Gautier J. A. , Renault J.
Published: September 2010

Les composés à double fonction pyridinium quaternaire (bis‐pyridiniums) conduisent, au moyen de l'oxydation ferri‐cyanhydrique, aux bis‐pyridones‐2 correspondantes qui sont elles‐mêmes aisément hydrogénables (nickel de Raney) en bis‐pipéridones‐2. Ces dernières présentent la constitution de bis‐lactames d'acides δ‐amino‐valériques N‐substitués, et sont, comme telles, transformables en bis‐amino‐acides. Ceux‐ci ont pu être isolés et fournissent des dérivés bien définis tels qu'esters et amides.
The determination of the position of the double bond in mono‐ethenoid fatty acids
Authors: Begemann P. Haverkamp , Keppler J. G. , Boekenoogen H. A.
Published: September 2010

Methods hitherto used for determining the position of the double bond in the fatty acid molecules are somewhat crude and unreliable when applied to fatty acid mixtures. Applying partition chromatography to the analysis of fatty acid oxidation products more reliable results were obtained. Experiments have shown that ozonisation and permanganate oxidation in glacial acetic acid cause only a slight secondary disintegration of the dibasic acids formed, but that permanganate oxidation in acetone is less suitable.

The improved method as described does not yield fully quantitative results, but it is sufficiently good to permit valuable conclusions to be drawn. The method is checked by the analysis of pure samples of various fatty esters. “Vaccenic acid” obtained by partial hydrogenation of tang oil has been proved to be a mixture of isomeric oleic acids.
Pyridine‐N‐oxide as an intermediate for the preparation of 2‐ and 4‐substituted pyridines
Authors: den Hertog H. J. , Overhoff J.
Published: September 2010

A description is given of methods for the preparation of 4‐, 2,4‐ and 3,4‐substituted pyridines, e.g. 4‐aminopyridine. the N‐oxide of pyridine or derivatives of pyridine is used as an intermediate to make e pyridine nucleus accessible for substitution in positions 2 and 4.
The energy of localization
Authors: Ketelaar J. A. A. , van Dranen J.
Published: September 2010

The energy of localization (KooymanandKetelaar) of one pair of π‐electrons is calculated for benzene and for naphthalene, in the latter case for the 12 bond and for the 23 bond. The usual L.C.A.O. approximation of the molecular orbital method is applied in zero approximation with neglect of overlapping integrals and in first approximation with these integrals equal to 0.25.

The values found in the zero approximation are 27.4 (benzene), 22.7 (12 bond naphth.) and 31.2 kcal (23 bond naphth.): in a first approximation 30.2, 21.8 and 36.3 kcal, respectively. The observed difference in the rate of the reaction of ozone with benzene and naphthalene is in accordance with these results.
Studies of gas absorption. VI. A graphical representation for the efficiency of physical absorption
Authors: van Krevelen D. W.
Published: September 2010

Equations for the absorption rate coefficient and the efficiency of absorption are derived.

A graph is given by which the application of these relationships is considerably simplified.
Oxidation of alkyl groups attached to the naphthalene nucleus
Authors: Pickering G. B. , Smith J. C.
Published: September 2010

By the action of N‐bromosuccinimide the side‐chain of an alkyl‐naphthalene is brominated on the α‐carbon atom (allyl system). Removal of hydrogen bromide gives an olefin which is easily oxidised to the naphthoic acid.
N‐Methylated menthylamines and piperitylamines
Authors: Read John , Cuthbertson William Wilson
Published: September 2010

The N‐methyl‐ and N‐dimethyl‐derivatives of l‐ and d‐neomenthyla nines, as well as the corresponding trimethylammonium iodides and hydroxides, have been described by Read and Hendry

J. Read and J. A. Hendry, Ber. 71,2544.

). Corresponding derivatives of d‐iso‐ and d‐neoisomenthylamine have now been prepared and characterised, together with those of the closely related l‐piperitylamine. d‐neoisoMenthylamine has been obtained in a new way, starting from l‐piperitone.
Radiochemical test of orthophosphate‐pyrophosphate separation
Authors: van der Straaten H. , Aten A. H. W.
Published: September 2010

Preliminary to an investigation of the Szilard‐Chalmers process in crystalline phosphates we wished to test the reliability of the separation of pyrophosphate from orthophosphate.
La réaction du tétrahydrure de lithiumaluminium sur quelques composés organiques soufrés
Authors: Strating J. , Backer H. J.
Published: September 2010

LiAlH4 réduit les rhodanures et les sulfochlorures en mercaptanes. Par contre, on obtient les disulfures, en réduisant les chlorures sulféniques, les acides sulfiniques, les chlorures sulfiniques et les 1,2‐disulfones. La plupart des disulfures peuvent être réduits par LiAlH4 en mercaptanes, mais cette réaction s'accomplit très lentement.

La formation aisée de mercaptanes aux dépens des rhodanures et des sulfochlorures ne s'accomplit donc pas par l'intermédiaire des disulfures.

Le comportement des esters sulfoniques d'alcools aliphatiques primaires et secondaires est très remarquable. Soumis à l'action de LiAlH4, ils donnent naissance à l'acide sulfonique et à l'hydrocarbure dont l'alcool se dérive.
Kinetic analysis of organic halides. II. Analysis of macromolecules built up of monohalide units
Authors: Salomon G. , Koningsberger C.
Published: September 2010

A number of hydrochlorides of natural and synthetic rubbers and allied polymers have been prepared and subjected to kinetic analysis with organic bases. The hydrochlorides of natural rubber react at 100° C with a rate identical with that of low molecular tertiary chlorides. At 50° C the reactivity of the polymer is, however, reduced by physical factors.

The hydrochloride of GR‐S (a synthetic rubber made from butadiene and styrene) has been prepared for the first time by heating the swollen polymer with HCl under pressure. Kinetic analysis of this product revealed two fractions; the expected secondary chloride and a small fraction of a very reactive (tertiary?) chloride.

After elimination of experimental difficulties, we succeeded in the preparation and kinetic identification of the pure tertiary hydrobromide of natural rubber. Attempts to prepare the secondary bromide under peroxide conditions failed.

Kinetic analysis of two types of Neoprene revealed the presence of a small quantity of allylic groups in the polymer, while 95% of the chlorine in Neoprene has the expected stability of a vinyl chloride. This stability can be used for the identification of Neoprene.
A rapid determination of the average molecular weight of rubber in hevea latex
Authors: van Essen W. J.
Published: September 2010

A method is described for determining viscometrically the molecular weight of rubber in freshly tapped latex. For this purpose the latex is dissolved in a toluene‐pyridine mixture. From the intrinsic viscosity of this solution the molecular weight of the rubber can be determined, using the Staudinger equation and a known viscosity constant. Molecular weights have been found, varying between 238000 and 480000, depending on the kind of clone. Rubber in fresh latex does not have a lower molecular weight than in old preserved latex.
Synthèse de Stérols à Chaînes Latérales Variées
Authors: de Vries Harmen , Backer H. J.
Published: September 2010

Afin de synthétiser les stérols ayant des chaînes latérales différentes, les auteurs ont préparé quelques céto‐stéroïdes dont la fonction cétone se trouve dans la queue, soit en position 22 soit en 24.

On transforme le groupe carbonyle en groupe méthylène par l'intermédiaire des mercaptals cycliques de dithioglycol, que l'on soumet à une décomposition réduisante au moyen de nickel Raney.

Après avoir vérifié l'applicabilité de cette méthode en synthétisant le cholestérol, les auteurs s'en sont servis pour la synthèse du 25,25‐bis‐desméthyl‐cholestérol et du 25‐desméthylcholestérol (le dernier produit selon deux voies).
Nouveaux Dérivés du Dibenzofuran et de Ses Isologues
Authors: Buu‐Hoï Ng. Ph. , Royer René
Published: September 2010

Dans ce travail, on continue l'étude des dérivés du dibenzofuran, notamment par la description de nouveaux 3‐acyldibenzofurans, et d'une série de 3‐alkyldibenzofurans préparés par réduction de Clemmensen des cétones correspondantes. On montre que ces homologues du dibenzofuran peuvent être acylés à leur tour au moyen de la réaction de Friedel‐Crafts. Une étude parallèle a été faite dans les séries isologues du dibenzothiophène et du fluorène, et de nombreux 2‐alkylfluorènes et 3‐alkyldibenzothiophènes ont été synthétisés et leur réactivité étudiée sur la réaction de Friedel‐Crafts. Plusieurs composés indoliques ou quinoléiniques se rapportant aux cétones précédentes sont décrits également ici:
Compounds related to provitamin D3 (II). The sulphur analogue of provitamin D3
Authors: Strating J. , Backer H. J.
Published: September 2010

The preparation of the sulphur analogue of provitamin D3 is described. Bromination of S‐acetyl‐cholestene‐5‐thiol‐3, followed by elimination of hydrogen bromide, did not give good results.

The synthesis has been realised by applying these reactions to cholesteryl rhodanide; 7‐dehydrocholesteryl rhodanide so obtained submitted to selective reduction by means of LiAlH4 afforded cholestadiene‐5,7‐thiol‐3.

Bis‐(7‐dehydrocholesteryl‐3)‐disulphide, which may be prepared from 7‐dehydrocholesteryl rhodanide, could also be reduced by means of LiAlH4 to the same sulphur analogue of provitamin D3.
Syntheses of polychloro compounds with aluminium chloride IX. The preparation of octochlorocyclopentene by the direct condensation of trichloroethene and carbon tetrachloride
Authors: Prins H. J.
Published: September 2010

This paper describes the preparation of octochlorocyclopentene in one step from trichloroethene and carbon tetrachloride by the slow addition of trichloroethene to an excess of boiling carbon tetrachloride in the presence of aluminium chloride.
An interpretation of the influence of temperature on the bromination of bromobenzene
Authors: Wibaut J. P. , Sixma F. L. J. , Lips H.
Published: September 2010

At high temperatures a sudden change in substitution type occurs in the bromination of the halogeno‐benzenes. The theory, wich was developed for the bromination of naphthalene vapour, is applied to these cases and gives satisfactory agreement with the experimental results. The absence of a similar change in the substitution type in the bromination of phenol is discussed.

The bromination of bromobenzene vapour under the influence of light was studied; illumination results in a lowering of the temperature range in which the substitution type changes. This is a further proof of the correctness of the hypothesis underlying our theory, i.e. the development of a radical type of reaction at high temperatures.
Amidines derived from benzoylacetonitrile
Authors: Veer W. L. C.
Published: September 2010

This paper deals with the preparation of amidines derived from benzoylacetonitrile and 4‐methoxy benzoylacetonitrile. They showed marked analgesic activity.
Catalytic hydro‐desulphurization of gas oil: Contribution of hydrofining studies to the clarification of the structure of the sulphur compounds present in gas oil
Authors: Hoog H.
Published: September 2010

In the course of a study on desulphurization of mineral oils by catalytic hydrogenation, it was recognized that this hydro‐desulphurization reaction may also contribute to the clarification of the nature of the sulphur compounds present.

To this end, by means of model experiments with pure synthetic sulphur compounds, an analysis was first made of the gross type of reactions occurring when sulphur compounds are decomposed by hydrogenation into H2S and hydrocarbon fragment(s). The results conclusively indicate that under the conditions chosen and with the type of catalyst used the picture definitely is not that known from hydrocracking: the reaction is virtually limited to a rupture of C‐S‐bonds and hydrogen‐saturation of free valency. Our type of catalyst did effect hardly, if at all, the hydrogenation of aromatic rings present in the sulphur compounds. Only in the case of dibenzothiophene was partial hydrogenation of the rings observed. Parallel experiments with more aggressive catalysts invariably showed considerable aromatic saturation.

The results of these model tests were then used in the interpretation of hydrogenation experiments made with a full range gas oil of Middle East origin.

In a large number of experiments carried out on this gas oil, the reaction product was scrutinized for the presence of low boiling hydrocarbons. As in no case more than traces of gaseous hydrocarbons or liquid hydrocarbons distilling below 200°C could be found, it is evident that no sulphides and di‐ or polysulphides can have been present in the feed stock. As it was known from chemical analysis that no mercaptans are present either, the sulphur compounds in our specific gas oil must preponderantly be of the thiophene (or thiophane) type.

By hydrogenation of a concentrate of the sulphur compounds (obtained by extraction of the gas oil with liquid anhydrous hydrogen fluoride), it was possible to study the corresponding hydrocarbons more closely. By means of careful chromatographic analysis it was shown that these were for about 60 % of aromatic and for 40 % of naphthenic nature, and that only few, if any, non‐cyclic hydrocarbons were present. Consequently, the original thiophene or thiophane compounds present in the gas oil investigated are not of the alkyl thiophene or alkyl thiophane type. They presumably consist as to about 30‐40 % of thiophenes (thiophanes) which contain one homocyclic ring and in about 70‐60 % two homocyclic rings which are not in the condensed configuration are present next to the thiophene (thiophane) ring.

No conclusion can be drawn as to the relative proportion of naphthene and aromatic rings in the original sulphur compounds.
Transposition intramoléculaire de nitrophénylsulfonylurées: (Les propriétés du groupe sulfonyle XIII)
Authors: Backer H. J. , Groot J.
Published: September 2010

La transposition intramoléculaire des nitrophénylsulfonyl‐urées 2) est un processus assez général, auquel les auteurs ont soumis les dérivés o‐ et p‐nitrophénylsulfonyle de plusieurs urées et iso‐urées. En perdant le soufre sous forme d'anhydride sulfureux, les composés donnent des nitrophénylurées et éventuellement des produits de réactions secondaires.

Aux dépens des o‐ et p‐nitrophénylsulfonyl‐alkyl‐iso‐urées, on n'obtient pas les nitrophénylalkyl‐iso‐urées, mais leurs produits d'hydrolyse, les nitrophénylurées.

Les o‐ et p‐nitrophényl‐alkyl‐isothio‐urées, soumises à l'action de bases, n'obtiennent pas la chance de se transposer parce qu'elles perdent directement une molécule de mercaptane. Le produit final de la décomposition est un thioéther.

En étudiant, pour quelques nitrophénylsulfonylurées, la vitesse de la transposition — au moyen d'un dosage de l'acide sulfureux à des temps définis ‐ les auteurs ont pu vérifier l'hypothése sur le mécanisme.
The structure of cyclized rubber
Authors: van Veersen G. J.
Published: September 2010

The history of cyclized rubber, including a series of structural formulae previously proposed for this polymer, is reviewed briefly.

A new formula for cyclized rubber is suggested by applying electronic interpretations of reactions between electrophilic agents and tertiary alkyl olefins and tertiary halides respectively, to the corresponding reactions with rubber and rubber halides.

It is shown that hydrochlorination can be used for the determination of the unsaturation of cyclized rubber. By varying the conditions of hydrochlorination two types of double bonds can be detected in cyclized rubber, a fact which is in agreement with the structure suggested.

By using our method for the determination of the unsaturation, the rate of cyclization at different temperatures and the influence of solvents on the rate of reaction have been determined.
Preparation and properties of 1‐methylcyclohexadiene‐1,4
Authors: Haak F. A. , Wibaut J. P.
Published: September 2010

1‐Methylcyclohexadiene‐1,4 (C7H10) is obtained by reducing toluene by the method of Wooster. The structure of this hydrocarbon follows from the formation of acetone on decomposing the oxidation products with dilute hydrochloric acid. The addition products C7H10Br2, C7H10 Br4 and C7H11Br3 are described.
Etudes dans la sêrie du thiophène VI. La chimie du 2‐p‐tolylthiophène et du 2‐p‐chlorophénylthiophène
Authors: Buu‐Hoï Ng. Ph. , Hoán Nguyen
Published: September 2010

Dans ce travail, les auteurs étudient la réactivité de 2 arylthiophènes: le 2‐p‐tolylthiophéne et le 2‐p‐chlorophénylthiophéne, préparés à l'aide de la réaction de Gomberg à partir du thiophène et des chlorures de p‐tolyl et p‐chlorophényldiazonium en milieu alcalin. II est montré que dans cette réaction, il se forme comme sous‐produits au moins deux ditolylthiophènes et deux bis(chlorophényl)thiophènes. Le 2‐p‐tolylthiophène et le 2‐p‐chlorophénylthiophène possèdent une forte réactivité, dûe à la présence d'une position x libre sur le noyau thiophénique, comme le montrent la bromuration par la N‐bromosuccinimide et les réactions de Friedel‐Crafts. A partir des cétones ainsi obtenues, de nombreux corps nouveaux ont été synthétisés: acides, indoles, quinoléines, pyrrocolines, pyrimidazoles, α,β,β‐triaryléthénes, etc.…, dont certains font d'objet d'études biologiques.
The ionic conductivity of Li‐halide crystals
Authors: Haven Y.
Published: September 2010

The ionic conductivity of mixed crystals of Li halides and Mg halides has been measured. From these measurements the mobility of Li vacancies and the concentration of vacancies in pure Li halides has been derived, with the two assumptions that the defects in Li halides are Schottky defects and the mobility of halide vacancies is negligibly small.

The conductivity can be represented by an equation of the form:

x = A exp(‐U/kT)[1 + {1 + (4 A′/a2) exp(‐E/kT)}½]

in which x is the specific conductivity, U the height of the potential barrier which must be surmounted by the Li+ ions when moving through the crystal, E the energy required for the formation of a pair of vacancies, a the concentration of Mg halide and A′ and A constants.

The magnitude of E, U, A and A′ (table I) have been compared with theoretical estimates.
Untersuchungen über Rotationsdispersion III
Authors: Lifschitz I.
Published: September 2010

In Ergänzung früherer Mitteilungen wird über weitere Untersuchungen der Metallkomplexverbindungen des Oxymethylencamphers berichtet. Insbesondere werden die bemerkenswerten Rotations‐ und Razemisationsverhältnisse der Chromiverbindung beschrieben. Die Absorptionsspektra und Dipolmomente der Oxymethylencamphorate und Acetylacetonate der dreiwertigen Metalle Al, Cr, Co und Fe werden mitgeteilt und kurz diskutiert.
The solubility of MgF2 in solid LiF
Authors: Haven Y.
Published: September 2010

From work on the ionic conductivity of LiF‐MgF2 mixed crystals the solubility of MgF2 in solid LiF has been derived at temperatures from 400 to 700° C. The solubility is of the order of magnitude of several percent. The rules given by Goldschmidt for the miscibility of ionic substances have been extended. Apart from the similarity in ionic radius which was emphasized by Goldschmidt, the gain in polarization energy upon solution of the solute also has to be considered. This polarization energy is particularly important in cases where the solute contains ions with a valency different from that of the solvent ions.
Emission spectra of some chemoluminescent reactions. Part I. The oxidation of dimethylbisacridinium nitrate
Authors: Spruit‐van der Burg A.
Published: September 2010

The emission spectra of the chemoluminescent reaction between dimethylbisacridinium nitrate and hydrogen peroxide in alkaline solution have been determined at three different temperatures.

At 94° the spectrum closely resembles the fluorescence spectrum of methylacridone, which is one of the end products of the reaction. It is however not completely identical with this spectrum as it is much broader.

The hypothesis of Kautsky and Kaiser that the spectrum of the light emitted at room temperature is a combination of the high temperature spectrum and the fluorescence spectrum of dimethylbisacridinium nitrate has to be rejected. The spectrum at low temperature represents a second luminescent process. At 51° a spectrum is emitted which can be described as a combination of the spectrum at 94° and that at room temperature.

In the determination of chemoluminescence and fluorescence spectra one has to account for the fact that part of the emitted light is absorbed by the reactants. A method is given to correct accurately for the influence of this phenomenon.
Thiosemicarbazide as a reagent for the identification of aldehydes, ketones, and quinones
Authors: Sah Peter P. T. , Daniels T. C.
Published: September 2010

For chemotherapeutic studies and for evaluation of thiosemicarbazones as characteristic derivatives for the identification of carbonyl compounds, a large number of thiosemicarbazones have been prepared. The virtue of thiosemicarbazide as a reagent in qualitative organic analysis has been discussed. Most of the thiosemicarbazones prepared show very high in vitro antitubercular activity. A few of them have been shown to possess activity even higher than that of streptomycin.
A new synthesis of aryl‐aliphatic alcohols : II. Cyclamen alcohol and cyclamen aldehyde
Authors: Beets M. G. J. , van Essen H.
Published: September 2010

The method described in the first paper of this series is applied to the synthesis of cyclamen alcohol and cyclamen aldehyde.
Determination of dipole moments from measurements on diluted solutions
Authors: Scholte Th. G.
Published: September 2010

Starting from Onsager's theory and an extension of it given by Böttcher a method is given for computing dipole moments from data of diluted solutions in non‐polar solvents. The dipole moments determined in this way agree rather well with those computed from gas data.
Entrainment distillation as a reference method for the determination of the water content of foods: I. Theoretical aspects of analytical dehydration with special reference to entrainment desiccation
Authors: Overbeek J. Th. G. , Mossel D. A. A.
Published: September 2010

Thermodynamic considerations indicate that in a reference method for water determination it is imperative to choose the water vapour pressure (p), prevailing during the analysis, very low (order: 1 mm Hg), to prevent a retention of water, which surpasses the precision of the method (order: 0.1% abs.).

To reach the desiccation equilibrium in a reasonable time (≤ 8h) an elevated temperature is necessary; the upper limit of temperature is determined by the thermostability of the least stable component of the actual substrate.

Out of the existing methods, entrainment distillation with isooctane (bpt 99° C) was chosen, since in a comparison, incorporating thermodynamic, kinetic, chemical and experimental aspects, it showed the highest overall suitability.

For this technique p was found to be directly proportional to the solubility of water in the entrainer at the temperature of the receiver. For isooctane as an entrainer, p was calculated from solubility data and found to be of the order of 1 or a few mm Hg, involving a total retention of water equalling 10‐30 mg for an intake of 10‐20 grams. The retention of water by the boiling entrainer was calculated and turned out to be negligible; the amount of water dissolved by the entrainer in the receiver was calculated and found not to surpass 10 mg.

Kinetic considerations revealed that under “ideal” conditions dehydration of the normal intake in entrainment distillation can be completed in about ½ hour.

The additional time of operation (∼ 5 h), noticed in practice, must be attributed to slow sedimentation and collection of small water droplets and to internal transport phenomena in the substrate.
On electro‐osmosis and streaming‐potentials in diaphragms: II. General quantitative relationship between electro‐kinetic effects
Authors: Mazur P. , Overbeek J. Th. G.
Published: September 2010

A general proof is given for the equality of the streaming‐potential E/P and the electro‐osmotic transport of liquid V/I, independent of the structure of the diaphragm. The presence of surface conductance and even inhomogeneity of the material from which the diaphragm is constructed, does not impair this relation. Three other relations involving also the streaming current and the electro‐osmotic counter pressure, can easily be derived on the same base.

The proof is given by two independent methods, one method using a model of a diaphragm, which consists of a network of simple capillaries, the other treatment being based upon die thermodynamics of irreversible processes.
Deacylation of acylamino‐nitrobenzenes with substituted benzoyl groups as acid radicals. Some cases of steric hindrance
Authors: Verkade P. E. , Wepster B. M. , Witjens P. H.
Published: September 2010

The rate constants for the (pseudo) catalytic deacylation of a number of benzanilide derivatives have been determined.

Discussion of the data obtained leads to the conclusion that in the deacylation of 2′‐substituted benzoylamino‐4‐nitrobenzenes, steric hindrance is exhibited in a very pure form, i.e. practically undisturbed by other effects of a steric or electric nature.
Molecular compounds of phloroglucinol and tertiary amines
Authors: Verkade P. E. , van Leeuwen M.
Published: September 2010

A number of molecular compounds of phloroglucinol and tertiary amines is prepared and analysed.
The degree of imperfection of crystals
Authors: Addink N. W. H.
Published: September 2010

An attempt is made to arrange crystals of various materials according to their degree of imperfection, derived from the apparent value of N (the Avogadro number). N has been determined for each kind of crystal according to the formula:

where M is the molecular weight, c a factor related to the number of molecules per unit cell, V the volume of the unit cell and d the density of the crystal. Metals, in accordance with their mosaic structure, show a relatively high value of N and therefore a high degree of imperfection (0.06% of their volume), whilst the lowest value of N has been found for diamond, quartz, calcite and potassium chloride (prepared from a solution). Special attention is drawn to the behaviour of perfect crystals of potassium chloride (from a solution) and imperfect crystals of the same substance (from the melt): adsorption phenomena of water vapour give rise to an estimation of the thickness of mosaic blocks. A value of 6 × 10−4 cm has been found, assuming a monomolecular layer of water molecules on the internal surface.
The polarisabilities and the radii of ions in solution
Authors: Böttcher C. J. F. , Scholte Th. G.
Published: September 2010

A method for the calculation of the polarisabilities and radii of ions in solution previously developed by one of the authors is applied to solutions of salts in mixtures of water and glycerol, to aqueous solutions of KF and to solutions of aluminium chloride in dilute hydrochloric acid. From the results of the measurements a further discussion of the method is given.
Ethyl‐β‐chlorovinyl ether
Authors: van Dorp D. A. , Arens J. F. , Stephenson O.
Published: September 2010

The preparation of ethyl‐β‐chlorovinyl ether from the readily available dichloroacetal is reported. Careful fractionation of the product yields the pure cis‐ and trans‐isomers of which only the cis‐isomer gives a high yield (76%) of ethoxy‐acetylene on heating with potassium hydroxide.

The corresponding ethyl‐β‐bromovinyl ether has likewise been separated into cis‐ and trans‐isomers.
Entrainment distillation as a reference method for the determination of the water content of foods: II. Development of a convenient method of entrainment distillation
Authors: Mossel D. A. A. , Reith J. F.
Published: September 2010

The procedure finally adopted is the following.

Entrainer: Pure isooctane (2.2.4‐trimethylpentane), bpt. 99° C.

Apparatus: Still of 8 cm diameter, capacity about 150 ml; heating by means of an oil bath kept at about 165° C.

Receiver of the Bidwell‐Sterling‐type; capacity of calibrated part 2 ml, cross section about 0.1 cm2.

Joints of one brand of glass, ground in.

Special features: Cleaning by hot chromic acid mixture; apparatus kept in this medium until use.

Bumping is prevented by the use of about 1 g of washed and dried pumice stones of øav =2 mm.

Creeping is prevented by the use of two glass wool mats, situated in the vertical tube, connecting still and receiver.

Water vapour diffusing from and to the apparatus is caught in a set of moisture control tubes (figures 1 and 3).

The main water column and droplets possibly sticking to the glass walls are transported to the calibrated part of the receiver with the help of a defatted copper wire.

Accuracy: Calibration on BaCl2. 2 H2O yielded a standard‐deviation s = 0.010 g, corresponding to a coefficient of variation C = 102 s/ x¯ = 0.55.

The average discrepancy between calculated and measured values was 30 mg.

“Constant” readings were reliable within less than 10 mg.

Time required for reaching constant readings ∼ 7 h.
Modification of sanchis' method for the determination of fluoride in drinking water
Authors: Boonstra Johanna P.
Published: September 2010

By an alteration of the zirconium‐alizarin ratio in the reagent the sensitivity of Sanchis' method is so increased that the latter becomes suitable for a determination with the aid of a photoelectric colorimeter.
Entrainment distillation as a reference method for the determination of the water content of foods: III. Application of the method developed to some model substrata
Authors: Mossel D. A. A. , Mossel‐Hens H. A. M. , Reith J. F.
Published: September 2010

The isooctane entrainment distillation technique, developed in a previous paper

D. A. A. Mossel and J. F. Reith, Rec. trav. chim. 70, 297‐312 (1951).

was applied to a set of model substrata, i.e. crystal hydrates, a choice of biocolloids and substrates rich in lipids and essential oils.

The data for hydrates and biocolloids obtained in the new technique were in satisfactory agreement with those arrived at using the best indirect reference method

J. H. van de Kamer and N. F. Jensen, Anal. Chim. Acta 3, 397‐404 (1949).

.

The entrainment distillation technique operated more quickly than this reference method and had a more general applicability, since substrates rich in lipids and essential oils did not offer any difficulties.

Slow dehydration of lactose hydrate and the necessity for neutralizing acid systems containing levulose or sucrose before desiccation are still disadvantages of the method.