bluuebunny/crossref_metadata_2025_split huggingface dataset:
Emission spectra of some chemoluminescent reactions. Part I. The oxidation of dimethylbisacridinium nitrate
Authors: Spruit‐van der Burg A. 
Published: September 2010

AbstractThe 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

AbstractFor 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.
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

Abstract
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

AbstractA 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

AbstractThe 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.
The degree of imperfection of crystals
Authors: Addink N. W. H. 
Published: September 2010

AbstractAn 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

AbstractA 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

AbstractThe 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

AbstractThe 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.
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

Abstract
The isooctane entrainment distillation technique, developed in a previous paperD. 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 methodJ. 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.
The theory of measurement of osmotic pressure
Authors: Staverman A. J. 
Published: September 2010

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

AbstractDe mème que la benzylallylsulfone3), ses dérivés méthyles en position α et β s'isomérisent sous l'influence d'un accepteur de protons, la double liaison se rapprochant du groupe sulfonyle. L'isomérisation de la benzylcrotylsulfone ne réussit pas dans les mêmes conditions.A moins qu'un substituant en position α n'encombre l'addition, les sulfones α‐oléfiniques qui résultent de l'isomérisation fixent des réactifs nucléophiles, ainsi que l'eau, l'alcool, le phénol et les mercaptannes en solution alcaline et la pipéridine.Le mécanisme des réactions d'isomérisation et d'addition est étudié et discuté en rapport avec les réactions analogues que présentent les sulfones cycliques des butadiènes.
The dehydrogenation of hydrocarbons by means of quinones: I. action of Chloranil
Authors: Dost N. , van Nes K. 
Published: September 2010

AbstractThe dehydrogenation of hydrocarbons with the aid of chloranil (tetrachloro‐p‐benzoquinone) is investigated.According to the literature, thus far all hydrocarbons dehydrogenated by this quinone invariably have proved to contain a partially hydrogenated aromatic nucleus. It has been shown in the present study that those hydrocarbons which contain a —CH—CH— group adjacent to an aromatic nucleus or to a double bond may be dehydrogenated by chloranil (at about 140° C). On the other hand it is impossible to dehydrogenate perhydro‐aromatics and aliphatics under the same conditions.When aliphatic olefins and cyclopentene derivatives are treated with chloranil, consecutive reactions prohibit the isolation of initially dehydrogenated products.The reaction mechanism of the dehydrogenations is discussed. The experiments are in line with the view that the reaction involves a free radical mechanism.
Quantitative investigation of the ozonisation of quinoline, isoquinoline and some of their homologues
Authors: Boer H. , Sixma F. L. J. , Wibaut J. P. 
Published: September 2010

AbstractThe addition of ozone to quinoline, 2‐ and 8‐methylquinoline, 2,3‐, 3,4‐ and 6,7‐dimethylquinoline and isoquinoline has been studied quantitatively.With the quinoline homologues the main initial reaction is an attack of the benzene ring, probably with the formation of a monozonide, which was rapidly converted into a 5,6‐, 7,8‐diozonide; the diozonide then reacts slowly to form a 3,4‐, 5,6‐, 7,8‐, 9,10‐tetraozonide. As a side reaction the pyridine nucleus is attacked initially; however this side reaction leads to the same tetraozonide.Isoquinoline adds on one molecule of ozone in the pyridine nucleus to the extent of about 60 % and two molecules of ozone in the benzene ring to an extent of 40 %.In none of the compounds examined was there any indication of the addition of ozone to a C=N bond.These conclusions, based on a determination of the quantities of ozone taken up, the amount of quinoline reacted and the amount of ammonia formed when the reaction product is hydrolised, are in agreement with the qualitative results of the ozonolysis of quinoline bases already published. 1)
Non‐newtonian flow of dilute polymer solutions: I. Outline of the Method
Authors: De Wind G. , Hermans J. J. 
Published: September 2010

AbstractA method is developed for the study of non‐Newtonian behaviour of dilute polymer solutions with a view to extrapolating the results obtained to infinite dilution. This method will be applied in the second part.The use of the capillary viscometer for this kind of work is discussed. As a check on the equation used some measurements with water, benzene and acetone are reported.
Tannin as a reagent for zirconium
Authors: Purushottam A. , Rao Bh. S. V. Raghava 
Published: September 2010

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

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

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

AbstractSome time ago 1) we described the formation of cinnamaldehyde by the action of boron fluoride ether on benzaldehyde. We suggested a possible mechanism of reaction: benzaldehyde gives benzyl alcohol by a Canizzaro reaction. The latter then reacts with boron fluoride ether with the formation of benzyl ethyl ether and ethyl alcohol. Dismutation of ethyl alcohol with benzaldehyde then gives acetaldehyde, which condenses with benzaldehyde to form cinnamaldehyde.In order to obtain support for the above suggestion we have made attempts to detect the presence of benzyl ethyl ether in the reaction mixture.
Non‐Newtonian flow of dilute polymer solutions: II Solutions of cellulose nitrate in acetone
Authors: de Wind G. , Hermans J. J. 
Published: September 2010

AbstractThe method outlined in part I *) is applied to solutions of cellulose nitrate in acetone. It is found that the non‐Newtonian character of the flow is strongly dependent on the polymer concentrations, but does not persist at the limit of infinite dilution. In other words, the non‐Newtonian character of the flow is not an intrinsic property of the polymer molecule but results from molecular interactions.The concentrations were varied between 0.05 and 0.2 g/100 ml. In one series we went up to 0.8 g/100 ml. The highest gradient attained was about 5.104 sec−1.
The influence of cations on the gelatin gel: II. The influence on swelling
Authors: Nobel P. C. 
Published: September 2010

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

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

AbstractThe electrolyte concentration at rapid flocculation of the AgI sol is measured in water‐acetone mixture for NaClO4, Ba(ClO4)2 and La(ClO4)3. There is a large drop in this value at high concentrations of acetone as is predicted in Verwey and Overbeek's theory of stability1). At medium acetone concentrations the AgI sol is stabilized, contrary to expectation.The theory of stability is extended on the basis of a model with double layers of Gouy‐Stern type on flat interacting parallel plates2). This theory explains the measured values if one assumes an attraction of the van der Waals‐London type. This attraction energy should be inversely proportional to d1.6 instead of to the square of the inverse distance, as is calculated by de Boer and Hamaker3).
Preparation et scission du phenylazo‐methylthio‐bis‐methylsulfonyl‐methane: Propriétés du groupe sulfonyle XXII
Authors: Backer H. J. 
Published: September 2010

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

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

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

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

AbstractThe chemisorption of hydrogen on a Ni‐catalyst obtained by coprecipitation from Ni(NO3)2, Na2CO3‐ and Na silicate solutions at 80° C and containing Ni and SiO2 in the ratio 3 Ni‐1 SiO2 was investigated.In agreement with other investigations it was found that the adsorption consists of a very rapid process followed by a much slower one, the latter increasing in velocity with increasing temperature. The transition between the two is not sharp but gradual. However, some distinction may be made by observing the amounts of hydrogen adsorbed at liquid nitrogen temperatures and very low pressure (type I) and the amounts which can be adsorbed in excess of this quantity (type II).It was found that a more thorough reduction of the catalyst resulted in an increase of the type I adsorption at the cost of type II. Adsorption of oxygen on a well‐reduced catalyst on the contrary decreased the type I and increased the type II adsorption, the change being linear with the amount of oxygen adsorbed. Oxygen adsorption can occur in two different manners. It is assumed that depending on the conditons one adsorption site can be occupied by either an oxygen atom or an oxygen molecule.Heating of a reduced catalyst in an inert atmosphere or under vacuum tends to eliminate the type I adsorption while also the total adsorption diminishes. It is suggested here that a reoxidation of the surface occurs (combined with some sintering). Two causes for this reoxydation are considered:
diffusion of oxygen in the interior of the metal—metaloxide structure to the surface
liberation of water vapour by the silica carrier followed by the reaction
Ni + H2O → NiO + H2.