bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence de L'empèchement Stérique dans les Synthéses D'indoles Selon E. Fischer
Authors: Hoí Ng Ph. Buu‐ , Royer René
Published: September 2010

II 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

Dans 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

Ersetzt 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

In 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

The 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

Measurements 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

The 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

On 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

On trouve, dans la littérature, deux phénothiazones (C12H7ONS), à savoir celle de Bernthsen

A. 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 Kehrmann

F. Kehrmann, Ann. 322, 54 (1902).

) (p.d.f. 165°—166°), dont la méthode de préparation a été modifiée par Pummerer et Gaszner

R. Pummerer et S. Gaszner, Ber. 46, 2324 (1913).

). Ce dernier corps est un fongicide assez énergique

Voir, 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.
The bromination of naphthalene V. A theoretical treatment of the non‐catalytic mono‐bromination of gaseous naphthalene above 300°
Authors: Sixma F. L. J. , Wibaut J. P.
Published: September 2010

In the non‐catalytic bromination of gaseous naphthalene below 300° the main product is α‐monobromonaphthalene. Between 300° and 500° the ratio of β‐bromonaphthalene to α‐bromonaphthalene increases rapidly with the temperature. At still higher temperatures this ratio remains constant and is approximately equal to unity.

It is assumed that the bromination of naphthalene proceeds as an electrophylic substitution at relatively low temperatures, whereas at high temperatures a radical substitution develops. A formula is derived which gives satisfactory agreement with the experimental values of the ratio of β‐ to α‐bromonaphthalene.
Etudes dans la Série du Thiophène. IV. ) Thiophénocarbazoles, thiophénobenzocarbazoles et leurs analogues isocycliques, et thiophénoacridines
Authors: Buu‐Hoï Ng. Ph. , Hoán Nguyên , Khôi Ng. H.
Published: September 2010

Dans ce travail, on décrit la synthèse et les propriétés d'une série de carbazoles polycycliques dérivant des benzocarbazoles et des dibenzocarbazoles par remplacement d'un des noyaux benzéniques par un noyau thiophéne (thiophénocarbazoles et thiophénobenzocarbazoles). Ces corps ont été préparés à partir d'arylhydrazines varieés d'une part, et d'autre part, du 2‐méthyl‐4‐céto‐4,5,6,7‐tétrahydrothionaphtène et du 2,7‐diméthyl‐3‐céto‐3,4,5,6‐tétrahydroiso‐thionaphtène. De nombreux composés analogues de la série isocyclique ont également été préparés à partir des mêmes arylhydrazines et de l'α‐tétralone, de son dérivé 7‐nitré, de la β‐tétralone, et de la 4‐méthylcyclohexanone. Au cours de ces recherches, on a apporté une contribution à la chimie des dérivés du thionaphtène et de l'isothionaphtène: en particulier, la synthèse du 2,4‐diméthylthionaphtène et du 2,6,7‐triméthyl‐3,4‐dihydroisothionaphtène a été réalisée. La plupart des carbazoles polycycliques décrits dans ce travail font l'objet d'études biologiques (pouvoir cancérigène éventuel). Le 2‐methyl‐4‐céto‐4,5,6,7‐tétrahydro‐thionaphtène et le 2,7‐diméthyl‐3‐céto‐3,4,5,6‐tétrahydroisothionaphtène donnent des réactions dePfitzinger‐Borscheavec l'isatine et son dérivé 5‐bromé, conduisant à des acides thiophéno‐dihydroacridine‐carboxyliques analogues au tétrophan.
Absorption spectrum and photodecomposition of o‐hydroxybenzenediazonium sulphate
Authors: de Jonge J. , Alink R. J. H. , Dijkstra R.
Published: September 2010

The long‐wave absorption maximum of o‐hydroxybenzenediazonium salts in water is found at 3950 Å, but in 50 % sulphuric acid as solvent it appears at 3500 Å.

While the photodecomposition of o‐hydroxybenzenediazonium sulphate in water leads quantitatively to a derivative of cyclopentadiene, decomposition of the same compound in 50 % sulphuric acid results for the greater part in catechol.

The effect of sulphuric acid, both on the spectrum and the photodecomposition, may be due to an increase in energy of the quinoid resonance structure of the o‐hydroxybenzenediazonium ion by the acid.
The solubility product of AgI and the complexes of AgI and iodide ions in water‐acetone mixtures
Authors: Mackor E. L.
Published: September 2010

The solubility product L of AgI in water‐acetone mixtures was determined from e.m.f. measurement in concentration elements. The diffusion potential was eliminated by Owen's method. As the solubility product was measured in three electrolyte concentrations the solubility product in infinite dilution could be found by extrapolation.

The complex formation of AgI2− increases with increasing acetone concentration. The equilibrium constant K = \documentclass{article}\pagestyle{empty}\begin{document}${\rm K}=\frac{{{\rm a}_{{\rm I}^-}}}{{{\rm a}_{{\rm AgI}_{\rm 2}^-}}}$\end{document} was also determined by e.m.f. measurements. ‐RT ln K proves to be a linear function of the acetone concentration in mole %.

The formation of higher complexes (AgnIn+m)m− is analysed. The complex Ag4I6= is the simplest complex that would confirm the experiment. A further proof has been found in the molecular weight determination in the ultracentrifuge.

The standard free energy of solution of AgI, ‐RT ln L, is a nearly quadratic function of the acetone concentration in mole %. At low concentrations of acetone (up to 50 vol. %) the influence on L is low, but at higher concentrations the solubility decreases rapidly.

The measurements were performed at 25.00 ± 0.02° C.
Structure and properties of compounds formed during the preparation of nickel‐on‐silica catalysts
Authors: van Eijk Van Voorthuijsen J. J. B. , Franzen P.
Published: September 2010

So far various metal hydrosilicates have been described in literature, but a detailed study of the components in the system metal oxide‐silica‐water occurring during the preparation of hydrogenation catalysts with added silica, has not been published. The results of a study of the system NiO‐SiO2‐H2O are given in this article, which also describes influence of the silica on the reducibility of the compounds.

The formation of nickel hydrosilicates under various conditions was studied by means of X‐ray diffraction and thermal analysis. At relatively low temperatures (under 100° C) badly crystallized compounds are formed; thermal analysis indicated the presence of incomplete hydrosilicates, viz. nickel antigorite and/or nickel montmorillonite. The degree of crystallization of these hydrosilicate gels can be much improved by hydrothermal treatment.

The stable end products resulting from this treatment are Ni(OH)2, Ni3(OH)4Si2O5 (nickel antigorite), Ni3(OH)2(Si2O5)2 (nickel montmorillonite) and SiO2 (quartz).

The reducibility with hydrogen was measured as a function of the temperature. It varies greatly both with the silica content and with the degree of perfection of the hydrosilicate structure, the hydrothermally treated nickel montmorillonite being of all the most difficult to reduce. Generally the reduction leads to formation of nickel in a cubic form; however in the case of the hydrothermally treated nickel montmorillonite and nickel antigorite gels there are indications that part of the reduced nickel atoms remain in the places they occupied as ions in the hydrosilicate structure.
2‐Phenyl‐cyclopropane‐1‐carboxylic acids: Researches on plant growth regulators XX. Structure/activity V
Authors: Veldstra H. , van de Westeringh C.
Published: September 2010

By means of their action on the oleate coacervate and of the UV‐absorption spectra the 2‐phenyl‐cyclopropane‐carboxylic acids of m.p. 91° C and 105° C could be identified as the trans‐ and cis‐forms respectively.

Of these acids, resembling very closely the trans‐ and cis‐cinnamic acids, the cis‐acid (m.p. 105° C) shows practically the same activity as cis‐cinnamic acid, whereas the trans‐acid, like trans‐cinnamic acid, is inactive.

So here spatially equivalent structures are also comparable as to their physiological activity.
The analysis of enzymatic protein digests
Authors: Lens J. , Evertzen A.
Published: September 2010

The chromatographic analysis of the amino‐acids of Stein and Moore can be extended to protein digests without much interference from the polypeptides present.

The free amino‐acids in such a digest can therefore be analyzed. Some examples are given.
Les Limitations de la Reaction de Kishner—Wolff
Authors: Buu‐hoï Ng. Ph. , Hoán Ng. , Xuong Ng. D.
Published: September 2010

Dans ce travail, on a étudié sur plusieurs exemples de réduction d'aldéhydes et de cétones, certaines limitations de la réaction de Kishner‐Wolff. Il est montré que deux limitations importantes sont dûes, l'une à l'empêchement stérique, l'autre, à la grande mobilité des atomes d'halogènes sur certains composés hétérocycliques ou aromatiques. Une troisième limitation, moins importante, est dûe à la transposition des dérivés nitrés en dérivés aci‐nitrés.
Time‐dependence of boundary tensions of solutions. II. Experimental determination of the kinetics and equilibrium of adsorption at liquid‐liquid interfaces
Authors: Ward A. F. H. , Tordai L.
Published: September 2010

Boundary tensions have been measured by the method of pendent drops for the interfaces between water and solutions of long‐chain fatty acids in hexane over a wide range of concentrations. At low concentrations the interfacial tensions were independent of the age of the surface. But above what appeared to be a critical concentration, characteristic of each fatty acid, the interfacial tensions decreased with time to final equilibrium values. For very low concentrations, below about 5 × 10−5 molal, the interfacial tension decreased linearly with concentration, the slope of the curve being identical for all the acids investigated (lauric, palmitic and stearic). In the concentration range where a time‐effect was observed, the fall in interfacial tension, and the time interval during which the fall occurred, both increased with increasing concentration. Experiments were carried out on the effect of varying temperature on the time‐effect. It was also shown that time‐effect occurred with an ester (ethyl palmitate).
Time‐Dependance of boundary tensions of solutions. III. Thermodynamics of the boundary‐bulk equilibrium of fatty acids in hexane‐water systems
Authors: Ward A. F. H. , Tordai L.
Published: September 2010

The activity of the solute in the adsorbed layer is calculated, and from this is obtained the activity in bulk by means of interfacial tension data at very low concentrations, using the method previously devised by the authors. This allows the investigation of the equilibrium between single and associated fatty acid molecules in hexane. It is shown that there is a simple equilibrium between monomers and dimers with lauric and palmitic acids, and the standard free energy of dimerisation is calculated, but the equilibrium with stearic acid is more complicated. The standard free energy of adsorption is calculated and it found to be independent of the chain‐length of the acid.
The acid strength of glucuronic acid in comparison with that of oxycelluloses
Authors: Hirsch P.
Published: September 2010

The interconvertibility of glucurone and glucuronic acid in dilute aqueous solution was investigated. Neutralization curves and neutralization constants (apparent dissociation constants) of free glucuronic acid were determined and compared with those of carboxyl groups in oxycelluloses.
Vapour pressures and heats of vaporization of benzene
Authors: Gottschal A. J. , Korvezee A. E.
Published: September 2010

Starting from two chosen experimental vapour pressure values of benzene, we have calculated:

1°. the vapour pressure curve up to the boiling point;

2°. the heats of vaporization along this curve.

The necessary additional information concerns specific heats and specific volumes. The formulae have been taken from the preceding paper.

The resulting vapour pressures are compared with the more recent Antoine equations. The heats of vaporization found along the same line prove to be in agreement with the calorimetric observations. Moreover, the calculations reveal with an appreciable precision the true form of the ΔH(T) relationship for benzene.
Researches on plant growth regulators XXII. Structure/activity VII: Sulphonic acids and related compounds
Authors: Veldstra H. , Kruyt W. , van der Steen E. J. , Åberg Böurje
Published: September 2010

At 10−4 ‐ 10−2 mol/l a number of sulphonic acids and related compounds, especially indole (3) methane‐sulphonic acid and 2,3,6‐trichlorophenylmethanesulphonic acid were found to be active as growth substances in the pea test, Avena straight growth test and flax root test. These acids being completely dissociated at physiological pH values, the anion must be the active form.

The relatively low structural specificity of the polar group in the side chain of active compounds is considered to be indicative for a physicochemical type of action.
Esters thiolsulfiniques
Authors: Backer H. J. , Kloosterziel H.
Published: September 2010

Les esters thiolsulfiniques se forment lorsqu'on fait réagir les chlorures arylsulfiniques sur les mercaptannes en présence de pyridine.

Les thiolsulfinates liquides ou dissous ne sont pas stables. Leur décomposition spontanée effectue une “disproportionnation” en disulfure et thiolsulfonate.

Pour les rayons ultraviolets tous les esters thiolsulfiniques présentent une absorption caractéristique qui change sous l'influence d'alcool.
Nitrating acids consisting of nitric acid and sulfur trioxide
Authors: Heertjes P. M. , Revallier L. J.
Published: September 2010

Some physico‐chemical properties of the system HNO3‐SO3are described. From the melting point curve the existence of some crystalline compounds could be derived. The very stable compound HNO3. 2SO3was isolated (m.p. 112° C), a compound ‐ possibly 2HNO. 3SO3‐ was found (m.p. 106° C), and a compound HNO3. 3SO3could be isolated (m.p. 41° C).

Liquid HNO3and SO3are not completely miscible. Between 90% SO3and nearly 100% SO3there exists a miscibility gap.

The vapour pressure diagram of the system HNO3‐SO3was also determined. The minimum in this diagram corresponds to HNO3. 2SO3. The vapour of mixtures on the HNO3side of this minimum contains HNO3and N2O5. On the SO3side of the minimum of vapour contains SO3.

It is posible to absorb most of SO3from contact gas in mixtures with 80‐82% of SO3at 25° C. In molten HNO3. 2SO3at 110° C the absorption of contact gas proceeds with a yield of over 90%.
Synthese und bacterizide Wirkung einiger quaternärer, höherer Alkyl‐ und Alkenyl‐bis‐(2‐oxyäthyl)‐Ammoniumsalze
Authors: Stefanović Gjorgje , Ćirić Jovan
Published: September 2010

Zur Prüfung der bactericiden Wirkung von quaternären Bis‐(2‐oxyäthyl)‐ammonium‐verbindungen mit höheren Kohlenwasserstoffresten wurden Decyl‐, Hexadecyl, Octadec‐9‐enyl, 11‐Cyclopent‐2′‐enyl‐n‐undecyl‐ und 13‐Cyclopent‐2′‐enyl‐n‐tridecyl‐bis‐(2″‐oxyäthyl)‐amine und die entsprechenden Amine, welche die den im Chaulmoograöl vorhandenen Fettsäuren entsprechenden Reste enthalten, hergestellt und mit Benzylchlorid umgesetzt.

Diese quaternären Ammonium‐salze besitzen eine hohe bactericide Wirksamkeit. Sie töten innerhalb von 2.5 Minuten S. aureus und B. Gaertner in Verdünnungen von 1: 1000 bis 1: 10000 ab.
Imenes derived from methylsulphonyl‐acetonitrile: (Properties of the sulphonyl group XLIII)
Authors: Dijkstra R. , Backer H. J.
Published: September 2010

When reacting diazomethane on nitriles of the type RSO2‐CHXCN, where X is a negative group, methylation on the nitrogen atom often occurs. In the case of bis‐methylsulphonyl‐acetonitrile, the N‐methyl derivative is formed exclusively: (CH3SO2)2CCNCH3. The less acidic methylsulphoxyl‐methylsulphonyl‐acetonitrile forms only the C‐methyl derivative: (CH3SO)(CH3SO2)C(CH3)CN.
Synthetic oxytocics. IV. 3‐(piperidyl‐(2)‐methyl‐) indoles and related compounds
Authors: Akkerman A. M. , Veldstra H.
Published: September 2010

The synthesis of a number of 3‐(piperidyl‐(2)‐methyl‐) indoles and of some related compounds is described, together with that of an additional number of 3‐(piperidyl‐(N)‐methyl‐) indoles (cf.). An analysis of the relationship between structure and oxytocic activity (data ofvan Proosdij‐Hartzemaandde Jongh) shows that several structural and spatial details, decisive for the activity of the ergot alkaloids, have no such influence with the synthetic compounds, though the importance of the general pattern of the alkaloids is discernable. So the 3‐(piperidyl‐(2)‐methyl‐) indoles are found to be less active and less specific than the 3‐(piperidyl‐(N)‐methyl‐)‐indoles.
The electrical conductivity of concentrated aqueous electrolytic solutions
Authors: Gellings P. J.
Published: September 2010

A semi‐empirical equation for the conductivity of concentrated electrolytic solutions is derived from the Debye‐Hückel‐Onsager limiting law. The comparison of this equation with experiment shows agreement within a few per cent, or better, up to 4 to 5 N and in one case even up to 11 N.

Measurements on NaNO3 up to 4.85 N and K5Fe(CN)6 up to 2.96 N are reported. Details of the null‐point detector and the variable‐frequency oscillator used in the bridge circuit are also given.
Investigations on sterols. VI The preparation of dihydrotachysterol2
Authors: Westerhof P. , Buisman J. A. Keverling
Published: September 2010

The preparation of dihydrotachysterol2 to be used as a standard in biological experiments was studied. The best yields were obtained by reduction of tachysterol2 with excess alkali metal, dissolved in liquid ammonia or suspended in a secondary amine. A laboratory method for the preparation of tachysterol2 is given.
Reduction potentials of various aromatic hydrocarbons and their univalent anions
Authors: Hoijtink G. J. , de Boer E. , van der Meij P. H. , Weijland W. P.
Published: September 2010

Potentiometric titrations of solutions of various aromatic hydrocarbons in 1,2‐dimethoxyethane and tetrahydrofuran with a solution of biphenylsodium have shown chemical reduction to proceed in two stages:

equation image

The reduction potentials of the aromatic hydrocarbons, calculated from the potentiometric curve, are in good agreement with the half‐wave potentials obtained from polarographic reductions in 96% dioxan‐water. The standard potentials of the first reduction step expressed in Volts against the standard potential of biphenyl fit the following equation:

with γ = ‐ 2.19 ± 0.059 e.V. (2 × stand. dev. from mean) in which a stands for the root of the m.o. secular equation (overlap S = 0.25 included) corresponding to the lowest non‐occupied π‐orbital of the hydrocarbon and γ is the resonance‐parameter.

The electrochemical series of aromatic hydrocarbons including a rough estimate of the standard potential of sodium in 1,2‐dimethoxyethane and the mechanism of chemical reduction in inert and proton‐active solvents are discussed.
Partition equilibria of indium halide complexes
Authors: Rossotti F. J. C.
Published: September 2010

In spite of many additional complications, the extraction of complexes with inorganic ligands may be treated in the same way as the extraction of complexes with organic ligands. A general method of deducing the formula of the extracted species from studies of partition equilibria is outlined. Application of this method to the partition of tracer concentrations of the indium halide complexes indicates that a number of different species may be extracted. Although the hydrated acido‐complex, HInX4, aq, is the predominant species extracted from halogen acid solutions, significant proportions of the trihalide and complexes or ion‐pairs such as NaInX4 partition from halide media at relatively low acidities. The relative extractability of indium into a number of organic solvents follows the same general order for solutions in hydrochloric, hydrobromic and hydriodic acids.
Die Struktur der Einschlussverbindungen des Wassers (Gashydrate) und des Phenols
Authors: von Stackelberg M.
Published: September 2010

Bezüglich der Gashydrate wird auf einige noch offene Probleme ihrer Struktur hingewiesen.

Für die Einschlussverbindungen des Phenols wird die Kristallstruktur angegeben.
Application of paper chromatography to the identification of accelerators and antioxidants : I. Introduction; detection of guanidines and thioureas
Authors: Zijp J. W. H.
Published: September 2010

In this paper the various difficulties in the identification of accelerators and antioxidants in rubber compounds are reviewed. A detailed procedure for the detection of four guanidine derivatives by paper chromatography is mentioned. The identification of diphenyl thiourea and diorthotolyl thiourea is also described.
Application of paper chromatography to the identification of accelerators and antioxidants: III. Detection of dithiocarbamates and thiuram sulphides
Authors: Zijp J. W. H.
Published: September 2010

In this paper a detailed procedure is given for the paper‐chromatographic separation and identification of dithiocarbamates, which are used as ultraaccelerators in the rubber industry. These dithiocarbamates decompose in acid medium into secondary amines. The salts of these amines are better soluble in water than the dithiocarbamates, and are therefore more suitable for a paper‐chromatographic separation.

A method for the simultaneous detection of dithiocarbamates and thiuram sulphides is also described.
Investigations on sterols XI : Preparation of 13α‐androstene derivatives
Authors: Bots J. P. L.
Published: September 2010

By irradiation of androst‐5‐en‐3β‐ol‐17‐one with U.V. light (λ>280mμ) 13α‐androst‐5‐en‐3β‐ol‐17‐one was obtained. This substance was converted into a mixture of the C17 epimers of 13α‐androst‐4‐en‐17‐ol‐3‐one, both of which were obtained in a pure state.
Analysis of fat soluble vitamins IV: Discussion of the chemical routine determination of vitamin D
Authors: Hanewald K. H.
Published: September 2010

Details of the already published49 procedure for the chemical routine determination of vitamin D have been investigated, especially the colorimetric determination with antimony trichloride and the elimination of tachysterol by addition of maleic anhydride.
Über die Nitrierung des N‐Oxyds des 3‐Hydroxypyridins
Authors: Lewicka Krystyna , Plaźek Edwin
Published: September 2010

Die Nitrierung des N‐Oxyds des 3‐Hydroxypyridins ist untersucht worden. Es wurde ein Mononitroderivat erhalten, welches sich als das N‐Oxyd des 2‐Nitro‐3‐hydroxypyridins erwies. Die Reduktion der Verbindung führte zum 2‐Amino‐3‐hydroxypyridin, die Reaktion mit PCl3und PBr3in Chloroform zur Bildung des 2‐Chlor‐3‐hydroxypyridins bzw. des 2‐Brom‐3‐oxypyridins.
Stereospecific synthesis and optical resolution of 5‐hydroxypipecolic acid
Authors: Beyerman H. C. , Boekee P.
Published: September 2010

The synthesis is described of 5‐hydroxypipecolic acid by reduction with sodium borohydride of the corresponding keto‐acid, which in turn was prepared from glutamic acid. This reduction proceeds without any appreciable formation ofallo‐isomer.

The optical resolution is also described and the rotations of the optical antipodes are compared with those mentioned in the literature for the natural product.

Further evidence is given for thecis‐OH/COOH configuration of theDL‐allo‐acid.
Square wave electrolysis IV. Results and discussion
Authors: Wijnen M. D. , Smit W. M.
Published: September 2010

The cyclic potential‐step method and the cyclic current‐step method are applied to two Red/Ox systems. Values of the standard exchange current density and of the transfer coefficient of both the ferro‐ferri system in 1M H2SO4 and the ferrocyanide‐ferricyanide system in 1M KCl are determined. The results obtained by the two methods are in good agreement with each other. A comparison is made with data obtained by other methods, mentioned in the literature.
The ozonisation and the ozonolysis of furan and of some methylated furans in connection with the reactivities of the bonds in the ringsystem
Authors: Jibben B. P. , Wibaut J. P.
Published: September 2010

The ozonisation and ozonolysis of the following compounds have been investigated: furan, 2‐methylfuran, 2,3‐, 2,4‐ and 2,5‐dimethylfuran and 2,3,5‐trimethylfuran. When dissolved in chloroform, these compounds take up about 1.6 mol of ozone per mol of furan derivative at –60°, and resinification is practically absent under these conditions. On decomposition of the resultant ozonides under a variety of conditions, dicarbonyl compounds are produced and they have been determined both qualitatively and quantitatively. Glyoxal, which may be produced from either the two β‐C atoms or one α‐ and one β‐C atom of the furan nucleus, is the sole dicarbonyl compound produced in the ozonolysis of furan. The same holds,mutatis mutandis, for the ozonolysis of 2,4‐dimethylfuran, where methylglyoxal is the sole dicarbonyl compound produced. In the ozonolysis of the remaining furan derivatives along with dicarbonyl compounds produced from the two β‐C atoms in the furan nucleus, there are produced also those derived from an α‐ and a β‐C atom of the furan nucleus. Thus, for example, in the ozonolysis of 2,3‐dimethylfuran, glyoxal and dimethylglyoxal are produced as well as methylglyoxal. Besides dicarbonyl compounds, considerable amounts of formic and acetic acids are also produced in the decomposition of the ozonides and these have been determined approximately.

The experimental results may be explained by assuming that two different reactions occur in the interaction of ozone and the furan derivatives examined. In the first reaction two molecules of ozone are taken up on the two α‐β‐bonds of the furan nucleus. On decomposition of the diozonide obtained there is produced a dicarbonyl compound containing the two β‐C atoms of the furan nucleus. In the second reaction only one molecule of ozone is absorbed. The mono‐ozonide on decomposition produces two dicarbonyl compounds, which contain one α‐ and one β‐C atom of the furan nucleus. During the decomposition of the ozonides hydroperoxides derived from the dicarbonyl compounds are produced as by‐products. The hydroperoxides partly decompose by peroxide transformation into carboxylic acids.

A reaction mechanism put forward byBailey and Colombto explain the occurrence of dicarbonyl compounds containing an α‐ and a β‐C atom from the furan nucleus, must be rejected for the furan derivatives we have studied on the fact that the take up of ozone was found to be 1.6 mol per mol of furan derivative.
The liquid‐junction potentials between some buffer solutions in methanol and methanol‐water mixtures and a saturated KCl solution in water at 25°
Authors: de Ligny C. L. , Rehbach M.
Published: September 2010

The determination of the liquid‐junction potential at the interface of an oxalate and a succinate buffer solution of known pH* in water, methanol or a methanol‐water mixture and a saturated KCl solution in water at 25° is described. When the pH* of such a solution is measured by means of a pH meter standardized by an aqueous standard solution, this liquid‐junction potential causes an error of over 2 pH* when the methanol content of the solution is high.
Investigations on sterols XV: The syntheses and properties of 9β,10α‐progesterone and 6‐dehydro‐9β,10α‐progesterone
Authors: Westerhof P. , Reerink E. H.
Published: September 2010

A description is given of the syntheses of 9β,10α‐progesterone and 6‐dehydro‐9β,10α‐progesterone using lumisterol2as the starting material.
Ultraviolet absorption spectra of some sterically hindered p,p′‐dimethoxystilbenes
Authors: Laarhoven W. H. , Nivard R. J. F. , Havinga E.
Published: September 2010

The ultraviolet absorption spectra of a series of methyl‐ and ethyl‐substituted p,p′‐dimethoxystilbenes were measured. The spectra could be described by assuming the presence of four overlapping absorption bands. Three of these bands, the positions of which (∼ 207, 230 and 285 mμ) are hardly affected by alkyl substitution, are tentatively interpreted as “benzene bands”; 4,4′‐dimethoxydibenzyl is found to show comparable absorptions. The fourth band (at 307 mμ in the case of unsubstituted 4,4′‐dimethoxystilbene) is assumed to correspond to an N → V transition in the stilbene chromophore. With the substituted dimethoxystilbenes the oscillator strength of this band decreases in the following sequence: α‐methyl‐ ; 2,2′‐dimethyl‐ ; 2,2′‐diethyl‐ ; α,2′‐dimethyl‐ ; α,2‐dimethyl‐ ; 2,2′,6,6′‐tetramethyl‐ ; α,α′‐dimethyl‐ ; α,2,2′‐trimethyl‐ ; α,α′‐diethyl‐ ; α,α′,2‐trimethyl‐ and α,α′,2,2′‐tetramethyl‐4,4′‐dimethoxystilbene.

There is an increasing hypsochromic shift that in general runs parallel to the decrease in extinction coefficient, λmax gradually falling from 307 mμ to ∼ 230 mμ.

The angles of twist (ψ) of the phenyl nuclei are estimated from the oscillator strengths of the long‐wavelength stilbene absorption bands. The values obtained show qualitative agreement with the results of calculations by the molecular orbital method as performed by Suzuki and by Riezebos.
Chemistry of acetylenic ethers XLVI: Addition of thiols to acetylenic ethers
Authors: Alkema H. J. , Arens J. F.
Published: September 2010

The free‐radical addition of ethanethiol to ethoxyethyne produces muchcisand a littletrans1‐ethoxy‐2‐(ethylthio)ethene, whereas the nucleophilic addition of sodium ethanethiolate yields 1‐ethoxy‐1‐(ethylthio)ethene.

The same applies to additions of other thiols.
Spectrophotometric investigations of the mechanism of complex formation: Part III. Complexes of aluminium chloride with bis‐(cyclopentadienyl)‐titanium dichloride
Authors: Adema E. H. , Bos H. , Vrinssen C. H.
Published: September 2010

Spectrophotometric titration curves of aluminium chloride with bis‐(cyclopentadienyl)‐titanium dichloride reveal the formation of two complexes: (C5H5)2TiCl2. (AlCl3)2and (C5H5)2TiCl2. (AlCl3)5. The spectra of these complexes are shown.
The influence of non planarity in styrene and stilbene derivatives III: Syntheses and ultra‐violet spectra of 4‐4′‐substituted cis‐ and transstilbenes
Authors: Riezebos G. , Havinga E.
Published: September 2010

A series of cis‐ and trans‐stilbenes magnified image, in which R = H, CN, NO2 and R′ = H, CH3, OCH3, have been synthesized and their ultra‐violet absorption spectra have been recorded. The differences between the spectra of the trans‐compounds and the sterically hindered cis‐isomers as well as the influence of the substituents on the spectra are discussed by means of a semiquantitative treatment.
Synthesis of enantiomeric mixed‐acid phosphatides
Authors: de Haas G. H. , van Deenen L. L. M.
Published: September 2010

The synthesis is described of two optically pure L‐α‐lecithins and of one D‐α‐lecithin, each containing one saturated and one unsaturated fatty acid, and of two enantiomeric α‐lecithins composed of two saturated fatty acids of unequal chain length. A modification of the procedure allowed the preparation of two structurally isomeric mixed‐acid L‐α‐phosphatidyl‐ethanolamines. The suitability of the synthetic phosphatides as substrates for biochemical model studies is demonstrated by experiments with snake‐venom phosphatidase.
The system iridium ‐ oxygen: II The dissociation pressure of IrO2
Authors: Cordfunke E. H. P. , Meyer G.
Published: September 2010

The dissociation pressure of IrO2 has been investigated. The results can be explained by the formation of a non‐stoichiometric oxide. This has been confirmed by X‐ray analysis. The composition of the IrO2‐x‐phase (in equilibrium with iridium) has been determined as a function of the temperature.

The oxygen pressure of the three‐phase equilibrium (IrO2‐x‐Ir‐G) can be represented by the equation:

For stoichiometric IrO2 from our measurements, it follows that:

ΔH298.16°K=−65.5(±1.5)kcal/mole.
Some characteristics of the hydration of 3CaO.Al2O3 in the presence of CaSO4.2 H2O
Authors: Stein H. N.
Published: September 2010

Experiments on the hydration of 3CaO.Al2O3 in a solution of Ca(OH)2 in the presence of CaSO4.2H2O are described. An approximate theoretical treatment of the retarded stage of this reaction is offered on the basis of water transport through a calcium hydrosulphatoaluminate (ettringite) layer on the 3CaO.Al2O3 particles as the rate‐determining step of the reaction. The water transport may be effected either by diffusion or by Poiseuille flow. The most plausible explanation of the experimental results is that the deposition of ettringite on the surface layer continues during the retarded stage, and that the surface layer expands at its outside more rapidly than the particles themselves shrink in the course of the reaction.
An improved synthesis of a mixed acid l‐α‐phosphatidylethanolamine, containing a polyunsaturated fatty acid
Authors: Daemen F. J. M. , de Haas G. H. , van Deenen L. L. M.
Published: September 2010

A method is described for the preparation of silver benzylN‐t‐butyloxycarbonyl‐2‐aminoethyl phosphate. A reaction between this substance and γ‐palmitoyl‐β‐linoleoylglycerol‐L‐α‐iodohydrin, after removal of the protecting groups, furnished γ‐palmitoyl‐β‐linoleoyl‐L‐α‐phosphatidylethanolamine in high yield.
Aromatic sulphonation VI: A kinetic study on the sulphonation and dealkylation oft‐butylbenzene in concentrated aqueous sulphuric acid
Authors: Cerfontain H. , Kaandorp A. W. , Sixma F. L. J.
Published: September 2010

t‐Butylbenzene has been sulphonated homogeneously in aqueous sulphuric acid solutions varying from 72.4 to 91.0 wt‐% at 5.0°, 25.0° and 35.0°. Under these conditions dealkylation oft‐butylbenzene occurs. Pseudo first order rate constants for the sulphonation and the dealkylation reaction have been determined.

The overall rate constant for sulphonation oft‐butylbenzene is smaller than that of toluene. It is suggested that this difference arises predominantly from increased steric hindrance fororthosubstitution in the former case.

The overall rate constant for dealkylation increases rapidly with increasing acid concentration: at 25° d(logkexp)/d (.‐HR) = 1.08, whereas d(logkexp)/d (‐H0) ∼ 2.0. The apparent activation energy for the dealkylation reaction decreases from 34.0 kcal · mole−1in 77.5 wt‐% sulphuric acid to 19.5 kcal · mole−1in 85.8 wt‐% sulphuric acid. Possible mechanisms for the dealkylation reaction are proposed and it is suggested that the C1ring protonation oft‐butylbenzene is governed by theHRacidity function.
Investigations on organotin compounds: Part XVIII. The basicity of triorganotin hydroxides
Authors: Janssen M. J. , Luijten J. G. A.
Published: September 2010

The basicities of a number of triorganotin hydroxides have been compared by measuring the acid dissociation constants of aquotriorganotin cations in 44% aqueous ethanol (by weight) at 25°. The equilibrium constants are given in concentration constants Kc, valid at an ionic strength of 0.01. Two series of organotin compounds were studied, namely trialkyltin hydroxides and mixed ethylphenyl derivatives. Basicities are influenced by inductive effects but also strongly by steric effects. Whether also an influence of d π ‐ p π overlap exists in the phenyltin series, cannot be clearly distinguished, because much if not all of the pK shift on introduction of phenyl groups can be explained in terms of inductive and steric effects.
Studies in IVth group organometallic chemistry: XII. Linear poly‐addition polymers derived fromp‐phenylene‐bis‐(dimethyltin hydride) and diphenyltin dihydride
Authors: Leusink A. J. , Noltes J. G. , Budding H. A. , van der Kerk G. J. M.
Published: September 2010

The preparation and characterization of linear organometallic polymers containing tin or tin and lead in the polymer main chain is described. These polymers have been obtained by poly‐addition reactions fromp‐phenylene‐bis‐(dimethyltin hydride) and various di‐olefinic, acetylenic and di‐acetylenic compounds. Reactions of this novel organotin hydride have also been carried out withp‐styrenyl derivatives of germanium, tin and lead, leading to monomeric compounds containing four hydrocarbon‐linked metal atoms.

Furthermore, linear polyesters and polyamides containing organotin radicals in the polymer backbone have been prepared from diphenyltin dihydride and difunctionally‐unsaturated esters and amides.
The separating performance of fractionating columns
Authors: Haring H. G. , Knol H. W.
Published: September 2010

The definitions of theoretical plate and separating power are discussed, and the concept of “plate equivalency”, now called the “separating performance” of a fractionating column, is worked out.

The separating performance is a dimensionless measure for the actual separation (the separating effect) obtained under conditions of partial reflux, as a counterpart to the separating power, which is a dimensionless measure for the maximum separation that can be obtained only attotalreflux.

A clear picture of the influence on the separating performance of a fractionating column exerted by variation of the reflux ratio can be gained by a new graphical representation, plotting separating performances against draw‐off percentages, instead of against reflux ratios.

The graph gives a simple illustrative explanation of a number of empirical distillation rules.