bluuebunny/crossref_metadata_2025_split huggingface dataset:
On indigo. V. A benziminazoline‐derivative, isomeric with indigo
Authors: van Alphen J. 
Published: September 2010

Abstract2‐(1′ : 3′‐Diketo‐hydrindylidene‐2′)‐benziminazoline is prepared by the condensation of 2‐methylbenziminazole and phthalic anhydride. This compound may be considered as being derived from indigo by interchanging imino and keto groups. Thus in one half of the molecule two imino groups are present and in the other half two keto groups. In many respects it resembles indigo, with the exception that its colour is yellow. Its constitution is proved by the fact, that 2‐ethyl‐ and 2‐benzyl‐benziminazoles do not give analogous products with phthalic anhydride.
Über das Koordinationsvermögen phenylierter Aethylendiamine. II. Verhalten von razemischem und aktivem Stilbendiamin
Authors: Lifschitz I. , Bos J. G. 
Published: September 2010

AbstractIm Gegensatz zur meso‐Verbindung besitzen razemisches und aktives Stilbendiamin nahezu normales Koordinationsvermögen und sehr viel geringere Neigung zur Bildung gelber Tetramminnickelsalze. Es wird eine grössere Anzahl von Komplexverbindungen dieser Amine beschrieben und magnetisch sowie polarimetrisch untersucht. Auf Grund der vorliegenden Beobachtungen wird die Konstitution der gelben Nickelkomplexe diskutiert und ihre Formulierung als pseudo‐Koordinationsverbindungen (Nickel‐Ammoniumsalze) begründet.
Die Oxydation von Gasförmigem Acetaldehyd durch Sauerstoff
Authors: Bodenstein Max 
Published: September 2010

AbstractAlte Versuche über diese Reaktion sind fortgeführt worden und haben zu der Erkenntnis geführt, dass die Reaktionsketten an der Wand beginnen, und zwar mit einer Umsetzung von Aldehyd mit der aktiven Form der Persäure, und beendet werden entweder durch eine Spaltung der letzteren oder durch ihre Reaktion mit Sauerstoff. Die aktive Form der Persäure ist das Radikal CH3C( O) (‐O‐O‐), die des Aldehyds das Radikal Acetyl. Diese Auffassung ist mit allen von den verschiedenen Forschern gemachten Beobachtungen im Einklang.
The determination of ecgonine alkaloids in coca leaves
Authors: de Jong A. W. K. 
Published: September 2010

AbstractA method is communicated by which it is possible to obtain from coarsely pulverised coca leaves, as they are sold at Amsterdam, the same quantity of cocaines and methyl ester of l‐ecgonine as is obtained from finely pulverised leaves. By converting the unknown ester of l‐ecgonine from the coca leaves into l‐cocaine it is proved that it is the methyl ester, which is present. This ester is present also in Cusko leaves.
A study on the physical constants of a number of alkanes and cycloalkanes: II. Additive and constitutional influences on molecular refraction, dispersion and parachor
Authors: Wibaut J. P. , Langedijk S. L. 
Published: September 2010

AbstractValues of the molecular refraction, calculated according to the formulae of Lorentz‐Lorenz or of Gladstone‐Dale are given for five different wave lenghts for a number of normal and branched alkanes and for a number of cyclanes. Additive and constitutional influences on molecular refraction and parachor are discussed. Exact values for the refraction equivalents of CH2C and H are given. Dispersions, specific and molecular dispersions have been calculated; the influence of homology and isomerism on the dispersion magnitudes is discussed.The temperature coefficients of the specific gravities and of the refractive indices (λ = 5876) have been calculated.
On the formation of 3, 3‐dimethylcyclohexanol‐1 and of 1, 1‐dimethylcyclohexane on catalytic reduction of 1, 1‐dimethylcyclohexanedione‐3, 5 (dimedone)
Authors: Wibaut J. P. , Gitsels H. P. L. 
Published: September 2010

AbstractWhen dimedone is reduced catalytically in 96% ethanol containing 1% hydrogen chloride in solution and with platinum (according to Adams) as a catalyst, there is formed about 58% of the theoretical amount of 3, 3‐dimethylcyclohexanol‐1 and 10% of the theoretical amount of 1, 1‐dimethylcyclohexane.
Die Einwirkung von Aryllithiumverbindungen auf Diarylketone. I. Die Bildung von Triarylcarbinolen
Authors: Faber A. C. , Nauta W. Th. 
Published: September 2010

AbstractDurch Einwirkung von Aryllithiumverbindungen auf Diarylketone wurde eine Anzahl von methylsubstituierten Tripenylcarbinolen erhalten. Wenn im Diarylketon mehr als zwei Orthomethylgruppen vorhanden sind, findet keine Carbinolbildung statt. An deren Stelle wurden in einigen Fällen Stoffe erhalten, denen vermutlich die Struktur eines methylsubstituierten 9,10‐Diaryl‐9,10‐dioxy‐9,10‐dihydro‐phenanthrens oder ‐anthracens zuerkannt werden muss.
Deacylation of aromatic acylamino compounds having a nitro group in the ortho or para position. Steric hindrance of resonance
Authors: Witjens P. H. , Wepster B. M. , Verkade P. E. 
Published: September 2010

AbstractThe work on the deacylation of aromatic acylamino compounds having a nitro group in the ortho or para position, in alcoholic medium under the influence of sodium alcoholate as a catalyst was continued. In this reaction the ‐E‐effect of the nitro group, the tendency toward electromerization of the o‐ or p‐nitrophenylamino grouping plays a predominant part. Typical cases of steric hindrance of resonance could consequently be ascertained with the help of this reaction.
Transformations “Ordre‐Désordre” dans les Réseaux Cristallins de Molécules Organiques, I. Propriétés physiques des molécules du Cα4, spécialement de C(SCH3)4
Authors: Backer H. J. , Perdok W. G. 
Published: September 2010

AbstractLe composé C(SCH3)4 a été étudié comme typique de molécule sphérique du type Cα4.Ćette substance présente un point de fusion élevé (65.5°), une cristallisation facile, une grande volatilité et une odeur camphrée.Elle se présente sous trois formes; deux sont tétragonales et la troisième, stable jusqu'au point de fusion, est cubique (cristaux plastiques). L'abasissement moléculaire du point de fusion est de 38° et l'entropie moléculaire de fusion n'est que de 3.6 cal/degré. A l'aide d'une courbe d'échauffement, on établit les points de transformation à 23.2, 45.5 et 65.5°. Les mesures thermiques donnent pour les chaleurs spécifiques des différente formes: I 0.21, II 0.23, III 0.31, liquide 0.34 cal/g/degré et pour les chaleurs moléculaires de transformation: Q1 146, Q2 1820, Q3990 cal. La phase cubique forme des cristaux mixtes avec le naphtalène.En déterminat la densité l'indice de réfraction et la constante diélectrique, on trouve le moment dipolaire μ = 0.50. La mesure de la réfraction moléculaire (RD = 57.21) nous met en état de fixer exactement la réfraction atomique du soufre dans les sulfures organiques (SD = 7.98). La tension superficielle à 70° est σ = 36 dynes/cm et le parachor = 419. Les propriétés spéciales de la phase cubique de C(SCH3)4 ne sont pas dues à une rotation des groupes SCH3 (examen Röntgenographique) ou des molécules entières (manque d'espace), mais à une orientaion désordonnée des molécules.
Sur la Quantité de Matière Cristallisée dans la Cellulose Régénérée: (Communication préliminaire)
Authors: Hermans P. H. 
Published: September 2010

AbstractEn opérant sur des fils‐modèles de cellulose régénérée d'orientation croissante, on a déduit du diagramme de diffraction de rayons X le degré d'orientation de leur partie cristallisée.En admettant que la biréfringence spécifique de la fibre de ramie est très voisine de celle de la cellulose cristallisée, on peut calculer la biréfringence que présenteraient ces fils, s'ils étaient entiérement composés de matière cristalline. La biréfringence observée étant sensiblement plus faible, il s'ensuit que les fils ne contiennent qu'une certaine fraction de matière cristallisée à côté d'une partie considérable de matière “amorphe”, qui du reste, contribue également à la biréfringence totale. Les données expérimentales ne permettent pas d'en déduire la quantité de la partie cristalline, mais seulement de fixer sa limite supérieure. D'une extrapolation vers l'orientation zéro on peut déduire que, pour l'état isotrope des objets étudiés, cette limite est de 20‐30 % environ. Si l'on admet avec M. Kratky que la quantité de matière cristallisée reste constante pendant la déformation, elle serait done au maximum du même ordre de grandeur pour les fils orientés.Il y a lieu de remarquer que si l'on considère les propriétés optiques de la cellulose comme celles d'un corps mixte binaire, d'après Wiener, les deux composants sont anisotropes.
Untersuchungen über Pilzfarbstoffe XVI: Synthetische Versuche zur Konstitutionsaufklärung des Phomazarins (III).
Authors: KÖgl F. , van Wessem G. C. , Elsbach O. I. 
Published: September 2010

AbstractEs wurde versucht, die Konstitution der durch oxydativen Abbau von Phomazarin‐(‐triacetat) erhaltenen Oxy‐methoxy‐n‐butyl‐phthalsäure auf synthetischem Wege zu beweisen. Da die Synthese dieses 5‐fach substituierten Benzenderivats auf Schwierigkeiten stiess, wurde die analytische Säure decarboxyliert und das Reaktionsprodukt mit synthetisch gewonnenem 3‐Methoxy‐4‐n‐butyl‐phenol identifiziert. Hierdurch sind die in der vorhergehenden Mitteilung für Phomazarin in Betracht gezogenen Formeln auch hinsichtlich Ring A bewiesen.
Presence of nicotinic acid (free and combined) in blood
Authors: Niemeyer J. A. 
Published: September 2010

AbstractAs the nicotinic acid level in urine seems to show no typical changes in the case of nicotinic acid deficiency, investigation of the amount of it in blood was attempted. The various methods give various results, and it is considered that a different technique is desirable, in which a distinction is made between the nicotinic acid which is free in the filtrate and that which is combined with the proteins when the blood is deproteinized. Nicotinic acid added to blood is found entirely as free nicotinic acid. Using a test curve in the colorimetric König reaction is not advisable, moreover it is possible to avoid its use, as was the case in this investigation.
A study on the adsorption of normal, branched and unsaturated fatty acids and related compounds by means of adsorption analysis
Authors: Claesson Stig 
Published: September 2010

AbstractIt has been shown that with a special type of silica as adsorbent all unbranched saturated fatty acids are adsorbed to the same amount from non‐polar solvents, independent of the length of the carbon chain. Branched fatty acids are adsorbed less and unsaturated more. The same rules are valid for the methyl esters of the fatty acids. It has also been shown that this phenomenon can be utilized for analytical purposes both by means of frontal analysis and displacement development. By the latter method it is possible to make a quantitative separation of a mixture of fatty acids into groups containing branched, normal and unsaturated compounds, respectively, which thereafter can be analysed for compounds with differing lengths of the carbon chain, with activated carbon as adsorbent. The adsorption of some other compounds have also been investigated using silica as adsorbent.
Researches on heat of combustion II: Internal lag and method of stirring in isothermally jacketed calorimeters
Authors: Coops J. , van Nes K. 
Published: September 2010

AbstractAfter a discussion of the requirements to be met by the method of stirring used in liquid calorimeters for accurate heat measurements, a description is given of a calorimeter constructed on a new principle. The development of heat occurs in a cylinder which is somewhat smaller than the calorimeter vessel. Water is circulated between the two walls, where the thermometer is placed by means of a centrally fixed centrifugal pump. In this way, the actual wall temperature of the calorimeter‐vessel is measured; this is essential for the accurate calculation of the “radiation” correction. A simple method is described for determining the heat due to stirring. Finally, the required minimum duration of the main period is discussed.
Influence de L'empèchement Stérique dans les Synthéses D'indoles Selon E. Fischer
Authors: Hoí Ng Ph. Buu‐ , Royer René 
Published: September 2010

AbstractII est montré que, contrairement è ce qui a été observé dans les réactions de Pfitzinger pour la synthése des quinoléines, l'empêchement stérique ne joue qu'un rôle beaucoup plus restreint en ce qui concerne les synthéses d'indoles selon la méthode d'Emil Fischer. Beaucoup de cétones stériquement encombrées qui ne donnent pas de réactions de Pfitzinger sont capables de conduire facilement à des indoles. En outre, la cyclisation de Fischer affecte de préférence un méthylène plutôt qu'un méthyle, alors que c'est en général le contraire dans les réactions de Pfitzinger.
Recherches Dans la Serie du Carbazole: I. Réactions, de substitution
Authors: Buu‐Hoí Ng. Ph. , Royer René 
Published: September 2010

AbstractDans ce mémoire, on décrit des réactions d'halogénation (chlorurations, bromurations) du carbazole et de quelques‐uns de ses dérivés N‐alkylés (N‐méthylcarbazole et N‐éthylcarbazole). On montre en outre que les réactions de Friedel‐Crafts sur les N‐alkylcarbazoles et les chlorures d'acides conduisent selon les conditions de la réaction, soit à des monocéones soit à des dicétones. Les carbazoles dans la molécule desquels l'une des 2 positions réactives (3 et 6) est bloquée par un atome de chlore fournissent également des monocétones. Les cétones de la série du carbazole donnent normalement la réaction de Pfitzinger avec l'isatine, ce qui conduit à une famille de corps rerrfermant à la fois le noyau de la quinoléine et celui du carbazole.
Über 1‐des‐aza‐adenin (7‐amino‐1‐imidazo (b)pyridin): 1. Mitteilung über des‐aza‐purin‐derivate
Authors: Kögl F. , van der Want G. M. , Salemink C. A. 
Published: September 2010

AbstractErsetzt man in der Formel eines Purin‐Derivats eines oder mehrere der Stickstoffatome des Ringsystems durch Methingruppen, so gelangt man zu Strukturtypen, für die sich durch Verwendung des Praefix „Des‐aza‐”︁ einfache Bezeichnungen ableiten lassen. Wir haben uns die Aufgabe gestellt, derartige Verbindungen zu synthetisieren und zu prüfen ob und inwieferne sie als Hemmstoffe physiologischer Prozesse wirksam sind.Die vorliegende Mitteilung beschäftigt sich mit der Synthese von 1‐Desaza‐adenin, dem von einem Imidazopyridin abgeleiteten Analogen des Adenins. Seine Darstellung hatte die Synthese des bisher ebenfalls unbekannten 2,3,4‐Triamino‐pyridins zur Voraussetzung.
A new method for the synthesis of furan derivatives: II. Preparation of δ‐sultones with two double bonds in the ring, starting with αβ‐ or βγ‐unsaturated ketones
Authors: Morel Th. , Verkade P. E. 
Published: September 2010

AbstractIn this paper directions are given for the preparation of δ‐sultones with two double bonds in the ring, starting with αβ‐ or βγ‐unsaturated ketones and a cold mixture of concentrated sulphurie acid and acetic anhydride in the molecular ratio of 1:2. The examples relate to nine of the eleven possible constitutional types.
The shape of macromolecules in solution and the interrelationships of their hydrodynamic parameters
Authors: Newman S. , Riseman J. , Eirich F. 
Published: September 2010

AbstractThe extrapolated values of the sedimentation constants of four polystyrene fractions in CHCl3, toluene and MEK were used, in conjunction with osmotic molecular weights and viscosity measurements, to calculate according to the Kirkwood‐Riseman theory the two fundamental molecular parameters b and ζ. Since the same parameters determine the translatory and rotatory diffusion constants, the latter could be calculated and were compared with experimental data on the same fractions from a concurrent investigation on the flow birefringence, and with translatory diffusion data of closely similar fractions. Finally, if the b and ζ values as obtained with the help of the sedimentation constant were introduced into the equation for the intrinsic viscosity, reasonable values for [η] were obtained, although the agreement was not as good as in the case of the diffusion data. It can be concluded that the correlation by means of the basic parameters b and ζ of the four hydrodynamic constants ‐ sedimentation constant, translatory and rotatory diffusion constant and the intrinsic viscosity ‐ is experimentally justifiable, and that the Kirkwood‐Riseman theory offers a satisfactory formalism for the description of these interrelations. There is also a direct correlation between the average chain length from hydro‐dynamic measurements and from light scattering. Earlier reported discrepancies turn out to be only apparent in the light of the present analysis.More specificially it was found that:
The sedimentation constants in infinitely dilute solutions are proportional to Mt/2, and that the slope and the intercept of this linear relation vary with the solvent.
The changes of shape indicated by the changes in S0 from solvent to solvent yield data from which the average molecular dimensions in the three solvents could be calculated. These dimensions fall in with the corresponding changes in [η].
The electrokinetic behaviour of iron‐ and aluminium‐hydroxides and ‐oxides
Authors: Schuylenborgh J. V. , Sänger A. M. H. 
Published: September 2010

AbstractMeasurements have been made of the electrophoretic velocities of ferric and aluminium‐oxides and ‐hydroxides in suspensions of variable pH, in order to establish the isoelectric point of these minerals. The results are:Goethite, isoelectric at pH 3.2; “limonite” at pH 3.5; lepidocrocite at pH 5.4; haematite at pH 2.1; böhmite and diaspore always negative and no isoelectric point; hydrargyllite at pH 4.8–5.2; corundum at pH 2.2.It is evident that the isoelectric points of these minerals are very different from those of freshly precipitated systems (α‐Fe2O3: 8.3; Al(OH)3: 8.2).The findings are discussed on the basis of the crystal structure of the minerals.
The mechanism of polymerisation reactions in liquid ammonia
Authors: Evans M. G. , Higginson W. C. E. , Wooding N. S. 
Published: September 2010

AbstractThe polymerization of styrene, methyl methacrylate and acrylonitrile is initiated by the amide ion in liquid ammonia, the product being a low molecular weight polymer containing one NH2 group per polymer chain. Other negative ions such as the triphenyl methyl anion also initiate polymerization. Certain disubstituted olefines such as α‐methylstyrene and diphenyl ethylene do not undergo polymerization but react with the amide ion forming intensely red‐coloured solutions.A mechanism for the polymerization is suggested, and the predicted dependence of molecular weight upon the concentration of potassium amide and of monomer (styrene) is in reasonable agreement with that observed in the concentration ranges studied in detail.The energetics of the initiation and termination reactions are discussed and the observed behavior of various monomers with a series of different anions is semi‐quantitatively explained.
Röntgenuntersuchung gelöster Fadenmoleküle
Authors: Kratky O. , Porod G. 
Published: September 2010

In the X‐ray scattering curve of chain‐molecules in solution, essentially four regions may be distinguished as is shown by a more detailed mathematical discussion:
The scattering at the smallest angles, showing an approximately Gaussean course, whose ordinate, when extrapolated to zero angle, is proportional to the square of the mol. weight. It is due to the diffraction effect of the whole coiled chain‐molecule.
This is followed by a region of v‐values where the scattering falls off as 1/v2. It is due to parts of the chain molecule which themselves already occur in all possible orientations.
After a transition region (which is also accounted for by the theory) there follows a scattering which is proportional to 1/v. It is to be considered as the scattering of mostly straight parts of the molecule.
The scattering at large angles, caused by smaller parts of the molecule (monomer group and single atoms), which at the same time indicates the periodicity (= length of structural unit in the direction of the chain axis) by a step, at an angle corresponding to Bragg's law. Its sharpness, too, is a measure for the coiling of the molecule.
It can be shown that the abscissa of the intersecting point of the 1/v2 and 1/v branches, when extrapolated to the transition region, is connected in a characteristic way with the statistical chain element or the “length of persistance”, which represent two different measures for the stiffness of the chain molecule.Measurements with polyvinyl bromide lead to a length of persistance of 11 ± 1 Å, which agrees satisfactorily with the value of 13 Å for polyvinyl chloride as derived from the birefringence of flow. At large angles two weak steps were found, one of which corresponds to the monomer length of 2.56 Å.Measurements on solutions of cellulose nitrate gave a curve ∼ 1/v without any steeper ascent up to the smallest angles, corresponding to 300 Å. We have, therefore, to conclude that the chain‐element of cellulose nitrate is in any case larger than 150 Å, which again is in agreement with the results of other physical measurements.Though only a small number of experimental results is available so far, it seems to be established that the procedure yields a direct evaluation of the shape of chain molecules in solution and, in this respect, appears superior to other methods. However, the experimental difficulties are considerable.
Dissociation and tautomerism of some quinone monoximes
Authors: Havinga E. , Schors A. 
Published: September 2010

AbstractOn a étudié l'absorption, dans le visible et dans l'ultraviolet, par les solutions aqueuses de quelques quinone‐monoximes à des pH's différents.Les courbes de quatre substances montrent un point “isosbestique” régulier; en calculant les pK's de la dissociation électrolytique en se basant sur les courbes tracées, on obtient des valeurs nettement constantes. On a obtenu les valeurs suivantes: benzoquinone‐monoxime. pK = 6.21 ± 0.03; 1,4‐naphtoquinone‐monoxime, pK = 8.01 ± 0.04; 9,10‐anthraquinone‐monoxime, pK = 9.78 ± 0.04; 3‐chloro‐benzoquinone‐4‐monoxime (P.F. 182° C), pK = 5.68 ± 0.03. Pour la benzoquinone‐monoxime, on a pu vérifier la valeur de pK par le titrage potentiométrique ainsi que par la déterminatior de la conductibilité.Les auteurs admettent qu'on peut interpréter le plus facilement les phénomènes de dissociation et de tautomérie pour les quinone‐monoximes en solution aqueuse par une simple équilibre de dissociation entre les deux formes tautomères et leur ion commun mésomère.La nature plus complexe, signalée déjà par plusieurs auteurs2) 3) 8) 9), de la forme fondante à basse température de la 3‐chloro‐benzoquinoneoxime (P.F. ± 140° C) apparaït aussi lorsqu'on observe les courbes d'absorption, qui, dans ce cas, n'ont pas de point d'intersection commun.
Sur la Phénothiazone
Authors: Olivier S. C. J. , Combé W. P. 
Published: September 2010

AbstractOn trouve, dans la littérature, deux phénothiazones (C12H7ONS), à savoir celle de BernthsenA. Bernthsen, Ber. 17, 2860 (1884); Ann. 230, 182 (1885).
), désignée par lui sous le nom d'oxythiodiphénylimide et qui commence à fondre dès 108° environ avec décomposition partielle, et le produit de KehrmannF. Kehrmann, Ann. 322, 54 (1902).
) (p.d.f. 165°—166°), dont la méthode de préparation a été modifiée par Pummerer et GasznerR. Pummerer et S. Gaszner, Ber. 46, 2324 (1913).
). Ce dernier corps est un fongicide assez énergiqueVoir, par exemple. M. C. Goldsworthy et E. L. Green, Phytopathology 29, 700 (1939).
).Dans le présent travail, on a amélioré le procédé de Pummerer et Gaszner qui s'était révélé non reproductible. On a trouvé ensuite que le produit de Bernthsen se compose, en majeure partie, d'un polymère de la phénothiazone renfermant e.a. une certaine quantité de monomère. Puis, on a modifié le mode de préparation d'après Bernthsen de manière que la phénothiazone, elle‐méme, devienne le produit principal de la réaction. Enfin. la nature du produit accessoire, se formant dans toutes ces réactions, a été discutée.