bluuebunny/crossref_metadata_2025 huggingface dataset:
The acid catalyzed cannizarro reaction of formaldehyde
Authors: Prins H. J.
Published: September 2010

It is shown that formaldehyde undergoes an acid catalyzed Cannizarro reaction in an acetic‐sulphuric acid medium as well as in an aqueous solution of sulphuric acid.

In an acetic‐sulphuric acid medium the reaction slows down when the sulphuric acid content is increased above a certain maximum.

In the same medium acetaldehyde is hydroxymethylated by formaldehyde a reaction which is followed by a crossed Cannirarro leading to esters of pentaerythritol and to its diformal compound (2,4,8,10‐tetraoxa‐6‐spiro‐undecane) which is easily prepared from the components in acid solution.

These reactions explain the formation of 2‐methyl‐2‐hydroxymethyl triacetate

S. Olsen, Z. Naturforschung 1, 676 (1946); Chem. Abstr. 44, 1130 (1950); J. W. Baker, J. Chem. Soc. 1948, 89.

in the condensation between ethene and formaldehyde.
Complex‐chlorides I. PCl5‐compounds. Preliminary communication
Authors: Groeneveld W. L.
Published: September 2010

During an investigation on the structure and the behaviour of addition‐compounds of PCl5 with the chlorides of elements, which do not belong to the alkali and alkaline earth metals, it turned out that a few compositions reported in the literature were wrong. Several new compounds have been prepared.
Steric effects on mesomerism. X . Deacylation of some tert.butyl‐acetylamino‐nitrobenzenes in an alkaline medium
Authors: Biekart H. J. B. , Dessens H. B. , Verkade P. E. , Wepster B. M.
Published: September 2010

This paper contains data on the influence of a tert.butyl group on the rate of catalytic alkaline deacylation of nitro‐acetanilides. Various cases of a steric effect on the mesomerism are discussed.
The preparation of higher fatty acids with an odd number of carbon atoms by the Arndt‐Eistert synthesis
Authors: Links J. , De Groot M. S.
Published: September 2010

Pentadecanoic, heptadecanoic and nonadecanoic acid were prepared from respectively myristic, palmitic, and stearic acid by the Arndt‐Eistert synthesis. The use of the Wilds and Meader variation for the rearrangement of the alkyldiazoketones, involving heating at 180° C with octanol‐2 or benzyl alcohol and γ‐collidine, gave fairly pure fatty acids. The reaction proceeded fast, and good yields were obtained. The advantage over the conventional Ag2O‐methanol method was especially marked in the case of nonadecanoic acid.

A chromatographic procedure, using silicagel as an adsorbent, petroleum ether as a solvent, and petroleum ether plus 25% ether as an eluent, was developed. This allowed a further purification of the products to pure fatty acids.
Une méthode générale de synthèse des acides gras supérieurs linéaires ou ramifiés
Authors: Buu‐Hoï N. G. Ph.
Published: September 2010

On décrit dans ce travail une méthode générale de synthèse des acides gras supérieurs dont la chaîne hydrocarbonée peut être linéaire ou ramifiée en des positions déterminées. Trois synthèses sont données en exemple: celles des acides palmitique, stéarique, et 15‐méthylpentadécanoïque.
On the separation of α‐keto acid dinitrophenyl‐hydrazones by ionophoresis and their polarographic estimation
Authors: Neish William J. P.
Published: September 2010

Rapid separation of synthetic mixtures of the 2,4‐dinitrophenylhydrazone derivatives of α‐keto acids has been effected by paper electrophoresis. The method has been applied to the separation of these derivatives from animal tissues and a polarographic procedure has been devised for the estimation of the hydrazones. Keto acid analyses are presented for organs from normal and tumour‐bearing rats.
The preparation of two new tetra‐alkoxysilanes
Authors: Breederveld H. , Waterman H. I.
Published: September 2010

Cyclohexoxy‐ and pentoxy‐3 tri‐tert.butoxysilane have been prepared from tri‐tert.butoxychlorosilane and the respective alcoholates. The specific refractions of these compounds deviate from the value calculated according to Smith1).
The effect of ortho methyl groups on the methylsulphonyl group, compared with their influence on the nitro group: (Properties of the sulphonyl group XXXIII
Authors: Kloosterziel H. , Backer H. J.
Published: September 2010

4‐Methylsulphonyl‐3,5‐xylenol has been prepared by a series of reactions involving thiocyanation, reduction with LiAlH4, methylation, and oxidation. The methylsulphonyl group exerts a negative mesomeric effect, which, however, is not hindered by ortho methyl groups. The spectrum as well as the ionization constant prove this. For the latter property, additivity of Hammett's σ‐constants for groups in the 3, 4, and 5 positions was taken as a criterion. For sulphur, as a second‐row element, coplanarity of its SO‐valencies and the benzene nucleus is no condition for maximum resonance. Throughout this paper, the data of the corresponding nitro compounds have been measured for comparison.
Syntheses of polychloro‐compounds with aluminium chloride XI: The reaction between carbon tetrachloride and 1,2‐dichloroethene
Authors: Prins H. J.
Published: September 2010

The course of this reaction depends largely upon the degree of dehydrohalogenation of the reaction products and upon the concentration of the 1,2‐dichloroethene. It is shown that by suitable variation of the experimental conditions the reaction can be used for the preparation of 1,1,2,3,4,5,5‐heptachloropentene‐1, a new compound C6Cl8, m.p. 94°, and the already known isomeric compound, m.p. 183°. The first mentioned isomer can be easily transformed into the latter.

A novel feature is the formation of small amounts of hexachlorocyclopentadiene, the origin of which is discussed. It is further shown that 1,1,2,3,4,5,5‐heptachloropentene‐1 reacts with 1,2‐dichloroethene to form the expected nonochloroheptene [1,1,2,4,5,5‐hexachloro‐3(1′,2′,2′‐trichloroethyl)‐pentene‐1].
2‐Methyl‐4‐phenylfuran and 1‐phenylcyclopenten‐1‐one‐3
Authors: Morel Th , Verkade P. E.
Published: September 2010

The substance described by Buchner and Schröder 3) as being 2‐methyl‐4‐phenylfuran has been proved to be 1‐phenylcyclopenten‐1‐one‐3.
The directive influence of the n‐oxide group during the nitration of derivatives of pyridine‐n‐oxide (II)
Authors: den Hertog H. J. , Henkens C. H. , Dilz K.
Published: September 2010

3,5‐Dibromopyridine‐N‐oxide, when heated with a mixture of fuming nitric acid and sulphuric acid, just like 3‐bromo‐ and 3‐ethoxypyridine‐N‐oxide, yields the 4‐nitro‐derivative. In 3,5‐diethoxypyridine‐N‐oxide, however, the nitro‐group enters the 2‐position.

3,5‐Dibromo‐4‐nitropyridine‐N‐oxide and 3,5‐diethoxy‐2‐nitropyridine‐N‐oxide are found to be phototropic substances.
The reactivities of alpha methylenic groups towards free radicals: II. Steric effects in alkylbenzenes
Authors: Kooyman E. C. , Strang A.
Published: September 2010

The retardation method 1) described previously has been applied to a number of polyalkylbenzenes. The reactivities of the alpha methylenic *) groups towards hydrogen abstraction by trichloromethyl radicals were compared with those of monoalkylbenzenes.

Compounds having two alkyl groups in adjacent positions ‐ with the exception of methylated benzenes ‐ were found to be far less reactive than expected on the basis of additivity. In these cases, scale drawings as well as model considerations show that coplanarity of the three remaining valencies at the alpha methylenic carbon atom is markedly interfered with by steric repulsions. With other isomers, reactivity appeared to be nearly additive.

The results are interpreted in terms of steric hindrance of resonance: geometrical arguments are put forward to show that this hindrance occurs not only in the final state — i.e. in the benzyl‐type radical formed upon hydrogen abstraction ‐ but also in the transition state.

The extremely low reactivity found for the anthracene‐maleic anhydride addition product is attributed to the fact that the bridge prevents formation of a planar radical.
The determination of formaldehyde in the presence of phenols and phenol alcohols
Authors: de Jong J. I.
Published: September 2010

A method described by Pfeil and Schroth 1) for the quantitative determination of formaldehyde appeared to be applicable in the presence of phenols and phenol alcohols.
Syntheses with the aid of γ‐picolyllithium I: Preparation of 4‐alkylpyridines
Authors: Wibaut J. P. , Hey J. W.
Published: September 2010

If phenyllithium in an ethereal solution is slowly added to an ethereal solution of the equivalent amount of 4‐methylpyridine, and an equivalent amount of an alkyl bromide is subsequently allowed to act on it, a 4‐alkylpyridine is formed as the main product of the reaction. In this way we prepared the 4‐n‐alkylpyridines, in which the alkyl group contains 3‐10 carbon atoms. The yields amount to at least 60% of the theory, calculated on lithium. By the action of phenyllithium on 4‐ethylpyridine, followed by the action of n‐butyl bromide, we obtained a 30% yield of the 4‐(hexyl‐2′)‐pyridine or 2‐(pyridyl‐4′)‐hexane.
Syntheses of polychloro‐compounds with aluminium chloride XII: The condensation of formaldehyde, chloromethyl methyl ether and of symm. dichlorodimethyl ether with 1,2‐dichloroethene
Authors: Prins H. J.
Published: September 2010

The present paper describes the formation of the di‐ether of 2,3,3‐trichloropropanol‐1 (2,3,3,2′,3′,3′‐hexachloro‐di‐n‐propyl ether) by the condensation of paraformaldehyde with 1,2‐dichloroethene and of the same ether together with 2,3,3‐trichloropropanol‐1 when trioxane is used as the source of formaldehyde.

The same ether is also obtained by condensing symm.‐dichlorodimethyl ether with 1,2‐dichloroethene. The condensation of chloromethyl ether with 1,2‐dichloroethene gives the methyl ether of 2,3,3‐trichloropropanol‐1.

The mechanism of these reactions is discussed.
A determination of methylol groups in condensates of urea and formaldehyde
Authors: de Jong J. I.
Published: September 2010

Methylol groups in condensates of urea and formaldehyde may be determined using an alkaline solution of potassium cyanide. Excess cyanide is back titrated with mercuric nitrate.
Polymerization of poly‐unsaturated fatty acid esters
Authors: Boelhouwer C. , van Steenis J. , Waterman H. I.
Published: September 2010

Polymerization of linseed oil and tung oil fatty acid esters at low temperature with atomic hydrogen was studied. In contrast with thermally polymerized esters the reaction products were not cyclic.
Analogues de la ρ‐hydroxypropiophenone dans la serie du biphenyle
Authors: Hoï Buu‐ , Xuong N. D. , van Thang K.
Published: September 2010

On décrit dans ce travail une série de cétones dérivées du 4‐hydroxy‐biphényle ayant une constitution analogue à celle de la ρ‐hydroxypropiophénone, et pouvant ainsi présenter un intérét biologique; quelques dérivés hétérocycliques de ces cétones ont également été synthétisés.
Cyclic oligomers of caprolactam: (An unusual case of stereo isomerism in higher‐membered rings)
Authors: Hermans P. H.
Published: September 2010

The low‐molecular substances other than caprolactam, present in hot water extracts of caprolactam polymerisates with an average DP of about 150, are investigated.

Using the guidance of X‐ray powder spectra of high resolution, three individual compounds have been isolated which together constitute the entire substance (or almost so). None of these compounds contains free COOH or NH2 groups, and their elementary composition is identical with that of caprolactam. They obviously represent cyclic oligomers of the lactam.

According to the molecular weight determinations in phenol, two of these compounds (m.p. 348° and 248°) are cyclic dimers and one (m.p. 242°) is a cyclic trimer. The first two, designated as the α‐ and β‐dimer, seem to represent stereo‐isomerides of the 14‐membered diamide ring system. The possible nature of this unexpected isomerism is briefly discussed.

Some properties and the X‐ray powder spectra of these compounds, together with those of some linear oligomers of ϵ‐aminocaproic acid synthesized by van der Want, are described.
Calculations of the heat of adsorption of hydrogen on platinum
Authors: Sachtler W. M. H.
Published: September 2010

The results of recent measurements on the work functions of a pure and a hydrogen‐covered platinum surface are used to calculate the heat of adsorption of hydrogen on platinum. The value obtained is compared with experimental results and with another theoretical value, calculated from Beeck's velocity constant, for the hydrogenation of ethylene on platinum by using a general relation between velocity constant and heat of adsorption as given by Beeck.
The binary system of selenium tetrachloride with aluminium chloride and of tellurium tetrachloride with aluminium chloride
Authors: Houtgraaf H. , Rang H. J. , Vollbracht L.
Published: September 2010

The binary freezing‐point diagrams of SeCl4AlCl3 and TeCl4AlCl3 were determined. Both systems show a dissociating compound in a molecular ratio 1: 1 with melting points of 163.8° C resp. 149.3° C.

In the case of the binary system SeCl4AlCl3 only one half of the system, with AlCl3 in excess, could be determined because of the decomposition of SeCl4 at higher temperatures. The compound TeCl4 · AlCl3 could be distilled in high‐vacuum without decomposition.

An approximate value for the heat of fusion of both addition compounds was calculated.
A new synthesis of aryl‐aliphatic alcohols: VI. Application of the method to 4‐styryl‐m‐dioxane
Authors: Drukker E. A. , Beets M. G. J.
Published: September 2010

By application of the method, described in the previous papers of this series2), to trans‐4‐styryl‐m‐dioxane, a mixture of 5‐phenyl‐penten‐4‐ol‐1 and 5‐phenyl‐pentanol is obtained in good yield. 4‐Phenylethyl‐m‐dioxane does not react under the same conditions.
Electrochemical behaviour of ion‐exchanging substances: VII. Characterization of the root substance by a continuous range of titration constants
Authors: MacGillavry D. , Tendeloo H. J. C.
Published: September 2010

For the interpretation of potentials of plant roots in electrolyte solutions it is desirable to know the variations with pH of net charge on the non‐permeating material inside the root wall. Since this is a very complex mixture, it is proposed to use as a model a solution characterized by a continuous range of titration constants.
The synthesis of compounds structurally related to isonicotinic acid hydrazide
Authors: Beyerman H. C. , Bontekoe J. S. , van der Burg W. J. , Veer W. L. C.
Published: September 2010

The synthesis is described of a number of 1‐ and 4‐substituted derivatives of pyridine related to isonicotinic acid hydrazide (INH) and of isonicotinoyl hydrazones of some aldehydes. These compounds were prepared in order to test them for possible growth‐inhibiting properties against Mycobact. tuberculosis.
Structure of α.ω‐diphenylpolyenes: II. Crystal structure of the monoclinic and orthorhombic modification of 1,10‐diphenyl‐1,3,5,7,9‐decapentaene
Authors: Drenth W. , Wiebenga E. H.
Published: September 2010

1,10‐Diphenyl‐l,3,5,7,9‐decapentaene crystallizes in a monoclinic and in an orthorhombic modification. Both structures have been determined by means of [010] and [100] Fourier projections. The value of the disagreement factor R ranges from 0.14 to 0.21 for the different modifications and projections; the standard deviations in the bond lengths are 0.03‐0.04 Å. In both modifications the conjugated chain of the molecule shows the all trans configuration; there exists, however, a small but significant difference between the general shapes of the molecules in the two structures. The atomic distances are compared with theoretical values, calculated by the method of molecular orbitals.
Polar effects in some atomic chlorinations
Authors: van Helden R. , Kooyman E. C.
Published: September 2010

The side‐chain chlorination of substituted toluenes as well as the atomic chlorination of some aliphatics t‐butyl‐X were investigated, using sulphuryl chloride as the chlorinating agent.

In both cases marked polar effects were observed. As in previous experiments with other strongly electronegative free radicals electronattracting groups cause a decrease in reactivity whereas electron‐repelling groups facilitate hydrogen removal.
Hofmann rearrangement of diphenylacetamide & ββ‐diphenylpropionamide. Schiff's base as a new by‐product of the Hofmann reaction. Benzhydryl‐amine from diphenylacethydroxamic acid
Authors: Rahman Aziz‐Ur , Farooq M. O.
Published: September 2010

In view of the lack of any systematic work already mentioned in the literature on the Hofmann reaction with amides containing two or more simple aryl groups in α‐ or β‐position, work was taken up on the Hofmann rearrangement of diphenylacetamide and ββ‐diphenylpropionamide, to serve as examples of αα‐ and ββ‐arylaliphatic amide respectively. Results indicated that while no special difficulty was encountered with ββ‐diphenylpropionamide, diphenylacetamide could be converted to the corresponding amine only in a more concentrated alkali solution than is customarily employed.

Experiments carried out to ascertain the optimum conditions for the successful Hofmann rearrangement of diphenylacetamide yielded, in dilute alkali solution, a new secondary reaction product – a Schiff's base, viz. N‐benzhydryl‐benzophenone‐imine, instead of the expected benzhydryl‐amine. A theoretical explanation has been submitted in support of this abnormal observation.

Benzhydrylamine has also been obtained through the Lossen rearrangement of N‐benzoyl‐diphenylacethydroxamic acid in about 20% yield; a by‐product, viz. N‐Nî‐dibenzhydryl‐urea, was isolated in 52% yield.
A possible function of vitamin K in photosynthesis
Authors: Wessels J. S. C.
Published: September 2010

It is postulated that vitamin K plays a part as energy acceptor and hydrogen donor in photosynthesis. Indications are given which may support this hypothesis. A possible function of vitamin K in the process of oxidative phosphorylation is suggested.
On the interpretation of the conductivity of soap solutions
Authors: Stigter D.
Published: September 2010

It is shown that measurement of the conductivity of micellar solutions provides a rather sensitive test regarding the size distribution of the micelles. In a number of systems the micelles are found to be practically uniform. In this case information on the equivalent conductance of the micellar soap can be obtained from the conductivity data in the range above the cmc. The data in the transition range (around the cmc) can be interpreted with the help of the law of massaction and lead to the molecular weight of the micelles.

Anomalous conductivity curves with a maximum slope just above the cmc are interpreted in terms of a wide size distribution of the micelles.
Simplified isolation of the non‐saponifiable matter in the analysis of oils
Authors: Mulder F. J.
Published: September 2010

A simplified method is given for the analytical isolation of non‐saponifiable matter from oils.

After saponification in alcohol the alcoholic soap solution is completely dissolved in a measured quantity of benzene and the benzene solution is washed with water. The concentration in the benzene solution is determined after drying. By this method the tedious operations of extraction and quantitative transfer of the extracts are avoided.

This method is suitable for the determination of the vitamins A and D.
Thermal rearrangement of sulphonylmethylnitrosamides (IVth communication on sulphonylnitrosamides)
Authors: de Boer Th. J.
Published: September 2010

Sulphonylnitrosamides, ArSO2N(NO)R, when heated in inert solvents, undergo first order decomposition into nitrogen and alkyl arylsulphonates (ArSO3R). A mechanism involving an intermediate diazosulphonate (ArSO2ONNR) is proposed.
Addition reactions of imenes
Authors: Dijkstra R. , Backer H. J.
Published: September 2010

Imenes most readily add amines and other nucleophilic reagents, such as water, alcohols, mercaptans, hydrogen sulphide, hydrocyanic acid. Bis‐methylsulphonyl‐N‐methylimene, which was studied more extensively, proved to possess not only electrophilic but also nucleophilic properties. Thus it adds HCl and can be applied in the Friedel‐Crafts reaction.
Ozone absorption and ozonolysis of cyclooctatetraene
Authors: Wibaut J. P. , Sixma F. L. J.
Published: September 2010

At −31° cyclooctatetraene absorbs 3.5 moles of ozone. Among the products of the ozonolysis of cyclooctatetraene, ethane‐1,1,2,2‐tetracarboxylic acid and succinic acid were found. The results may be interpreted either in terms of an equilibrium between cyclooctatetraene and bicyclo‐(4.2.0)‐octatriene or in terms of a reaction mechanism analogous to the one postulated by Friess and Boekelheide 10) for halogen addition.
Amperometrischer Nachweis von Ionen in Papierchromatogrammen
Authors: de Vries G. , van Dalen E.
Published: September 2010

Die Chloride und Perchlorate der Alkalimetalle lassen sich papierchromatografisch gut trennen, ihr Nachweis ist aber schwierig. Es wird ein Apparat beschrieben, mit dem die Ionen auf Grund des Stromdurchganges durch die Flecken gefunden werden. Der optimale Spannungsbereich sowie die Empfindlichkeit der Methode werden für die Ionen von Li, Na und K, einzeln und nebeneinander, erörtert.
On the determination of hydroperoxides
Authors: Wibaut J. P. , van Leeuwen H. B. , van der Wal B.
Published: September 2010

An improved iodometric procedure for the determination of hydroperoxides is described. Theoretical values are obtained for seven structurally different compounds. The estimation of 1‐tetralyl hydroperoxide is affected by the presence of α‐tetralone if the determination is carried out at too high a temperature.
On the theory of adsorption chromatography for liquid mixtures
Authors: Baylé G. G. , Klinkenberg A.
Published: September 2010

The theory of adsorption chromatography for liquid multicomponent mixtures is critically reviewed and it is shown to what limitations the introduction of a number of assumptions leads.

As regards the shape of chromatograms in development chromatography with two solutes, it is proved that both the discontinuous shape (Glueckauf) and the continuous one (Offord and Weiss) are consistent with the equilibrium theory, the shape to be found in a specific case depending on the mathematical characteristics of the adsorption isotherms that govern the process.

The most important check on theory will be to verify in what cases the relation, according to which all concentrations belonging to a given set move at equal velocity through a column, is valid.
The influence of caffeine on the coupling reaction between β‐naphthol and p‐diazobenzenesulphonic acid
Authors: Overbeek J. Th. G. , Vink C. L. J. , Deenstra H.
Published: September 2010

The rate of the coupling reaction between β‐naphthol and p‐diazobenzenesulphonic acid is lowered by addition of caffeine. This effect can be explained by complex formation between caffeine and the two reactants. The complex between caffeine and β‐naphthol is of the 1‐1 type; that between caffeine and p‐diazobenzenesulphonic acid probably also. Complexity constants have been determined. In the presence of caffeine the reaction follows two (or three) separate paths, one involving an activated complex consisting of one β‐naphtholate ion and one diazonium ion, and one (or two) involving an activated complex consisting of one molecule of each of the reactants and one molecule of caffeine. Rate constants have been determined at 20° C, using a colorimetric technique.
The reactivity of alpha‐methylenic groups towards free radicals: V. Azo‐compounds and ketazines
Authors: Kooyman E. C.
Published: September 2010

The reactivity of alpha‐methylenic groups in azo‐compounds and in ketazines has been investigated both theoretically and experimentally.

The results of molecular orbital calculations suggest that both groups of compounds are more reactive than olefins or alkylbenzenes. Reactivity measurements using the retardation method described previously lead to the same conclusion.
Steric effects on mesomerism: XIV. The basic strength of dibenzoquinuclidine and its bearing on the basic strength and the mesomeric energy of aromatic amines
Authors: van der Krogt S. M. H. , Wepster B. M.
Published: September 2010

The basic strength of dibenzoquinuclidine (III) is found to be about 3 pKa units lower than that of benzoquinuclidine (II). This corroborates an earlier conclusion that the inductive effect of a phenyl group introduced on the nitrogen atom of an amine, brings about a decrease of the basic strength of this magnitude.

Ultra‐violet spectra and the coupling (in) ability are discussed.
The preparation of non‐substituted amidrazones
Authors: van der Burg W. J.
Published: September 2010

The synthesis of a number of non‐substituted amidrazones is described. The compounds were prepared in order to test them for possible growth‐inhibiting properties against Mycobacterium tuberculosis. They were characterised by their N1‐benzylidene derivatives and some of them by their conversion into tetrazoles.
Production and physical properties of radioisotopes
Authors: Bakker C. J.
Published: September 2010

The production of radioisotopes in nuclear reactors and in cyclotrons is discussed. The types of nuclear reactions involved are mentioned. As to the production of radioisotopes, the cyclotron is an important complement to the nuclear reactor. Examples of disintegration schemes of radioisotopes are given. The loss of energy of β‐ or γ‐rays during their passage through matter is briefly discussed. The precautions necessary when working with radioisotopes are mentioned shortly.
Use of I131‐labelled substrates in the estimation of proteolytic and lipolytic enzymes
Authors: Brante G.
Published: September 2010

When I131‐labelled protein or fat is used as a substrate for proteolytic or lipolytic enzymes, respectively, unsplit substrate as well as split products are readily evaluated quantitatively by measurement of their radioactivity. The application of such substrates in the clinical estimation of enzyme activities has been tried by the author.
Total‐body γ‐radiation from patients with internally deposited thorium
Authors: Rundo J. , Faber Mogens
Published: September 2010

The application of a total‐body γ‐monitor using high‐pressure ionisation chambers to the measurement of radiation from patients is described. Patients with internally deposited thorium have been studied. The interpretation of the measurements in relation to the amount of thorium present, the age of the deposits, the accumulation of daughter products and the distribution of the thorium in the body is discussed.
Über die Anwendung der optischen Testmethoden Warburgs zur Untersuchung von Stoffwechselproblemen in der Klinik
Authors: Englhardt‐Goelkel A. , Prosiegel R. , Seitz W. , Stuhlfauth K.
Published: September 2010

Die Verfasser berichten über die Anwendung fermentativer Testmethoden zur Durchführung von Stoffwechseluntersuchungen in der Klinik. Diese Methoden beruhen auf dem Prinzip der Messung der Lichtabsorption des hydrierten DPN, das als Coferment am Ablauf vieler enzymatischer Reaktionen beteiligt ist. Alpha‐Ketoglutarsäure wurde mit Glutaminsäureoxydase, Brenztraubensäure mit Milchsäuredehydrase, beide nach Zusatz von DPNH, getestet. Die Ergebnisse zeigten, dass der alpha‐Ketoglutarsäurespiegel bei Gesunden im Mittel 0.17 mg% beträgt. Ersteigt deutlich im Fieber und nach peroralen und intravenösen Glutaminsäuregaben. Der Gipfel der alpha‐Ketoglutarsäurekurve nach Gluatminsäurebelastung liegt bei Leberkranken deutlich höher als bei Gesunden. Brenztraubensäure steigt besonders nach Fruktose‐ und Glukosegaben, und zwar nach Fruktose rascher und höher als nach Glukose.

Ausserdem wurden Messungen von Enzymaktivitäten in laparoskopisch gewonnenen Gewebsstücken aus menschlichen Lebern durchgeführt. Es wurden 5 Enzymssyteme getestet, an deren Reaktionen ebenfalls DPN als Coferment beteiligt ist: Aldolase, Triosephosphatdehydrase, Milchsäuredehydrase, Glutaminsäuredehydrase und Cytochrom‐C‐Reduktase. Nach Behandlung mit Leberextrakten war die Aktivität sämtlicher Enzymsysteme gesteigert.
Potentiometrische Chloridbestimmung im Blutserum, liquor cerebrospinalis und im Urin
Authors: Rosenmund H.
Published: September 2010

Es wird über eigene Erfahrungen mit der potentiometrischen Chloridbestimmung in Körperflüssigkeiten berichtet. Die Bestimmung beruht auf der direkten argentometrischen Titration der Chlorionen im nativen Untersuchungsmaterial. Das potentiometrische Verfahren ist genauer und rationeller als die gewöhnlichen Titrationsmethoden, es wird zur allgemeinen Anwendung in der klinisch‐chemischen Analyse empfohlen.
The reliability of the electrophoresis on filter‐paper of urinary proteins
Authors: Wolvius D.
Published: September 2010

It is pointed out that paper electrophoresis of urinary proteins gives reliable results only if the concentration of these proteins is at least two per cent.
The infrared spectra of some alkoxytrichlorosilanes
Authors: Stuart A. A. Verrijn , la Lau C. , Breederveld H.
Published: September 2010

The infrared spectra of methoxy‐, ethoxy‐, n‐propoxy‐, isopropoxy‐, cyclopentoxy‐, and cyclohexoxytrichlorosilane, and of methoxy cyclopentane have been measured. An interpretation is given, in which the attention is especially focussed on the skeletal stretching vibrations involving the SiO, C‐O and C‐C bonds.
The chemistry of acetylenic ethers XIII: Acetylenic ethers as reagents for the preparation of amides
Authors: Arens J. F.
Published: September 2010

In the presence of ethoxy‐ or methoxyacetylene an acid and an amine react very smoothly to yield an amide. The reaction has also been applied to the synthesis of peptides.
Studies on vitamin D and related compounds II: Preliminary communication on the interconversion and the possible cis/trans isomerism of previtamin D and tachysterol
Authors: Koevoet A. L. , Verloop A. , Havinga E.
Published: September 2010

Starting from the hypothesis that previtamin D and tachysterol may be cis/trans isomers, it has been found that previtamin D in solution readily transforms into tachysterol under the influence of small amounts of J2.
The estimation of small quantities of glycyrrhetinic acid in urine
Authors: van Katwijk V. M. , Huis L. G.
Published: September 2010

A method is described by which 20 mg of glycyrrhetinic acid/24 hours urine can be quantitatively estimated. This method is based on the fact that a solution of glycyrrhetinic acid in 96% ethanol gives a maximum absorption in the U.V. region at 248 mμ. By means of a chromatographic method, using floridine earth as adsorbing agent, it is possible to obtain the glycyrrhetinic acid sufficiently pure for the determination of the UV absorption spectrum.

With this method we investigated the urine of three patients who had been treated with this compound. No glycyrrhetinic acid could be demonstrated in these urines *).
The oxidation of phenols with copper‐amine catalysts and its relation to the mode of action of tyrosinase IV. Relations between hydrogen peroxide and the catalytic oxidation of phenols
Authors: Brackman W. , Havinga E.
Published: September 2010

In a previous paper a purely descriptive report was given on the kinetics of the catalytic oxidation of phenols with oxygen under the influence of copper‐morpholine complexes. Before discussing the mechanism of these reactions we thought it worth while to draw special attention to the ways in which H2O2 (a possible intermediate) may originate from and react with the catalytic systems under consideration.
Some thermodynamic properties of the system benzene ‐ 1,2‐dichloroethane. Part I: The heats of mixing
Authors: Ruiter L. H.
Published: September 2010

The heats of mixing of the system benzene ‐ 1,2 dichloroethane have been measured at three different temperatures (7.60°C, 25.00°C and 41.85°C) in a calorimeter of conventional design, using large quantities of liquid (350 ml). The apparatus and experimental procedure are described in detail. In the calculation of the heat exchange of the calorimeter with the surroundings, the method described by Coops et al 1) has been used. An elaborated heat‐of‐mixing experiment shows the application of this method to our calorimetric system.

The results of each series of experiments have been represented by an equation of the form:

ΔH/x (1−x) = a + b (2x−1) + c (2x−1)2 J/mole. The heats of mixing are positive, small and highly temperature‐dependent. They decrease with rising temperature.
The infrared spectrum of perchloromethyl mercaptan (trichloromethane sulphenyl chloride) CCl3SCl: Fermi‐splitting and isotope effect in the spectrum of carbon tetrachloride
Authors: Ketelaar J. A. A. , Vedder W.
Published: September 2010

The infrared spectrum of liquid CSCl4 has been measured from 3‐25μ. The experimental results are discussed and a complete analysis of the spectrum is given.

Although some corrections in his vibrational assignment had to be made, the spectrum supports the structure proposed by Duchesne1), i.e. CCl4 with a chlorine atom replaced by sulphur and a chlorine atom attached to the sulphur at an angle to the CS bond.

One of the fundamental frequencies shows Fermi‐splitting with a combination frequency. The difference between vapour and liquid state spectrum is used to prove the interpretation given. For comparison the shape of the Fermi‐doublet observed in the infrared spectrum of carbon tetrachloride is studied in the vapour and the liquid phase.
Potentiometric estimation of vanadium. II. Oxidation of Quadrivalent vanadium with KMnO4 in alkaline media
Authors: Issa I. M. , Daess A. M.
Published: September 2010

Quadrivalent vanadium occurring in alkaline solutions as alkali vanadite can be readily oxidized by permanganate. The latter is reduced either to manganate in the presence of Ba+2 ions or to MnO2. These reactions proceed almost quantitatively under certain conditions. A method for the estimation of vanadium is developed, based upon the oxidation of V+4 to V+5 with excess KMnO4 in alkaline medium, followed by titrating the excess of oxidant with formic acid or monovalent thallium. The method is applicable to quantities of V+4 as low as 604 γ.
Reactions of ethyl bromide and aluminium bromide. II. Isomerisation of ethyl‐[1‐14C] bromide
Authors: Sixma F. L. J. , Hendriks H.
Published: September 2010

The isomerisation of ethyl‐[1‐14C] bromide to ethyl‐[2‐14C] bromide in the liquid phase is catalysed by aluminium bromide. From measurements of the reaction rate at temperatures between +25° and +50° the activation energy of this reaction appears to be 19.1 kcal/mole (± 2%).
The absolute heat of combustion of benzoic acid
Authors: Coops J. , Adriaanse N. , van Nes K.
Published: September 2010

The heats of combustion of some samples of pure benzoic acid, partly supplied by the National Bureau of Standards (Washington) and partly prepared by the authors, have been carefully measured by reference to electrical standards.

The mean value of the absolute heat of combustion of benzoic acid under standard bomb conditions in some series of determinations carried out in the years 1946‐1948 is

26438 ± 4 j/g.

New determinations in 1954 showed a mean value of

26435 ± 4 j/g.
Plant growth activity and chemical structure
Authors: Schoot C. J. , Klaassens K. H.
Published: September 2010

A hypothesis relating to chemical structure and plant growth activity is formulated. The views of Hansch and Muir, Smith and Wain and Leaper and Bishop are correlated using as a basis the reaction between Ag3PO4 and phenoxyacetyl chlorides described in a previous article. The aryloxyacetic acids, the arylacetic acids and the arylcarboxylic acids are classified in the same scheme. Some indication is given as to the influence of the substituents in the phenoxyacetic acids. The rule of Leaper and Bishop is generalized.
Chemistry of the sydnones. I
Authors: Earl J. C.
Published: September 2010

The reduction of 3‐phenylsydnone is compared with that of compounds containing the N → O group. Fission of the molecule with unsymmetrical addition of hydrogen occurs in both cases.
Synthesis of 1,3,5‐tri‐tert. Butylbenzene
Authors: van Hartingsveldt W. , Verkade P. E. , Wepster B. M.
Published: September 2010

A synthesis is described of 1,3,5‐tri‐tert.butylbenzene starting from 3,5‐di‐tert.butyltoluene.
Complex coacervation. II. Thermodynamic calculations on a specific model, with application to two component systems
Authors: Voorn M. J.
Published: September 2010

In part II A, a general expression is given for the calculation of the free energy of a solution containing 2 or more interacting poly‐electrolytes in a salt solution.

From this expression, the conditions for thermodynamic equilibrium in 2 phase, j‐component systems are derived.

In part II B these conditions are applied to a two component system consisting of a colloid‐colloid “salt” PQ in H2O, in the absence of simple salt KA.
The phase behaviour of n‐alkanes
Authors: Schaerer A. A. , Baylé G. G. , Mazee W. M.
Published: September 2010

In the homologous series of n‐alkanes two alternating effects are known, viz. the familiar alternation of melting points for the short‐chain members and the recently reported alternation of transition points for members with chains of more than 20 carbon atoms.

A further study of the phase behaviour of these hydrocarbons now reveals that both effects are due to some peculiarity in one of two structures in which n‐alkanes may crystallize, viz. the Sβ‐modification. As a consequence, the thermodynamic properties of this solid modification show an alternation; this effect, in its turn, is responsible for the specific behaviour of the melting and transition point temperatures.

It is to be expected that the other crystal structure, viz. Sα, and the liquid do not show similar peculiarities.
Recent trends in the study of complex compounds
Authors: Sharpe A. G.
Published: September 2010

Three fields of complex chemistry which have attracted great interest during recent years are

The stabilisation of oxidation states by complex formation.

The correlation of magnetic and other physical properties with the structures of complexes as determined by X‐ray crystallography.

The factors which influence the reactivity of complexes, and the nature of substitution processes.

An attempt is made to review some of the major recent advances in each of these subjects, to indicate some of the difficulties involved, and to suggest in which direction further work is most likely to be profitable. Among the subjects to which reference is made are: recent work on complex fluorides; the stereochemistry of nickel and copper; the correlation of analytical uses with structure for metal derivatives of dioximes; and recent work on the mechanism of substitution in octahedral complexes.
Neuere Untersuchungen an komplexen Fluoriden
Authors: Hoppe R.
Published: September 2010

Es wird über die Darstellung einiger bislang noch unbekannter Alkali‐und Bariumfluorometallate berichtet. Ausserdem wurden mehrere bereits bekannte Verbindungen dieser Reihe erneut dargestellt und untersucht.

In vielen Fällen, nämlich bei der Darstellung der komplexen Alkalisalze, hat sich die von Klemm und Huss gefundene Methode der Fluorierung von Gemischen geeigneter binärer Salze (z.B. KCl + AgNO3) weiterhin bewährt; zur Erhaltung sehr homogener Präparate (insbesondere für magnetische Untersuchungen) ist es jedoch oft zweckmässiger, Komplexsalze entsprechender Zusammensetzung zu fluorieren.

Die Darstellung der Bariumfluorometallate gelingt im allgemeinen nur auf dem zweiten Wege. Dieses auffällige Verhalten hängt damit zusammen, dass bei Alkalisalzen primär die sehr aktiven Alkalifluoride MeFx (1 < × <3) gebildet werden, während beim Barium nur das hochschmelzende, reaktionsträge BaF2 entsteht.

Die Verbindungen wurden magnetochemisch, röntgenographisch und analytisch untersucht.
Complexes of the lower oxidation states of tungsten. II. Spectral data
Authors: Jonassen Hans B. , Cantor Stanley
Published: September 2010

The instability of the lower oxidation states of tungsten has been of considerable interest in recent investigations.

One of the compounds which has been extensively investigated is K3[W2Cl9]. The present work was undertaken in order to determine the multiplicity of the tungsten‐tungsten bond from infrared absorption and magnetic data.
Molecular complexes of dinitrogen tetroxide
Authors: Addison C. C.
Published: September 2010

Dinitrogen tetroxide forms molecular addition compounds with onium and π electron donors, and with anhydrous metal nitrates. Examples and possible structures of these compounds are discussed.
Di‐Isonitrilopalladium(O) compounds
Authors: Malatesta L.
Published: September 2010

The di‐isonitrilopalladium(O) compounds: Pd(RNC)2 (R = phenyl, p‐tolyl, p‐anisyl) in which the metal is in a formal zero oxidation state, have been prepared.

These compounds are of a type different from the ones with Ni and Cr as metals, e.g. Ni(RNC)4 and Cr(RNC)6, previously described by the author, and probably have a polymeric structure.
Ligand field theory of complex formation by ions of the first transition series, theoretical treatment: Data (ΔH and ΔS)
Authors: Griffith J. Stanley
Published: September 2010

Complex formation is discussed in terms of a molecular orbital model, and the energies of pairing d electrons in octahedral complexes are given in terms of atomic spectral parameters. The results are used to interpret Pauling's magnetic criterion and the variation of the heat of formation of a complex with change of central metal ion.
Electrometric study on equilibria in sodium silicate solutions
Authors: Lagerström Gösta
Published: September 2010

Aggregation of the silicate ion has been studied by accurate pH titrations of sodium silicate‐sodium perchlorate solutions ([Na+] being kept constant) at constant [Si]‐concentration, z̄ v. pH‐curves ( z̄ = average charge per silica unit) were calculated from the experimental data. These curves could be explained by assuming the formation of “core + links” complexes of the general composition H3SiO4‐(H2SiO3)n. The data which cover a limited range are compatible both with the formation of a single complex (n = 2, probably a ring) and with an unlimited mechanism (n = 1, 2, 3….). Equilibrium constants for both mechanisms are given.
Studies on the formation of composite complexes by means of an extractive technique
Authors: Rydberg Jan
Published: September 2010

For the interpretation of the data obtained on the extraction of metal complexes to organic solvents from aqueous solutions of low and constant ionic strength, the following minimum number of variables has to be considered: the concentrations of the metal atom (M), main ligand (the base A‐), HA, OH−, H2O, organic solvent molecules (Org) and the temperature. This has been done in an attempt to determine the compostion of the composite complexes of type MAn(OH)p(HA)r(Org)•(H2O)t formed in a given system.

In this complex s and t can be determined only in special cases, and it is not possible to distinguish by equilibrium methods between isomers with the same values for x = n + r and y = n + p. These isomers can be represented by the formula M(HA)x(H)−y.

It can be shown that in principal a distinction can be made between complexes of the type MAn, MAn(OH)p or MAn(OH)p(HA)r.

A general method to calculate formation constants for the complex M(HA)x(H)−y from extraction data has been developed. It is also shown that from a comparison of the distribution ratios of the metal between water and several different organic solvents it is possible to determine if the metal forms a complex with the organic solvent molecules.

The equations have been applied on the distribution of U(VI) and Th between several different organic solvents and water in the presence of acetylacetone.
Why are some metal‐binding substances anti‐bacterial?
Authors: Albert Adrien , Rees C. W. , Tomlinson A. J. H.
Published: September 2010

Very few of the common metal‐binding substances have anti‐bacterial properties, Nevertheless, 8‐hydroxy‐quinoline and its derivatives are powerful bactericides, and the anti‐bacterial action has been shown to depend on the intactness of the chelating structure1). Further, these substances are innocuous if traces of iron are removed from the testing medium2). The hypothesis has been evolved that they kill by transporting iron into the bacterial cell2).

The examination of related substances 3) suggested that two factors are necessary to make metal‐binding substances anti‐bacterial, (a) a high stability constant of the iron complex, and (b) a high partition‐coefficient in favour of lipids, to assist penetration of the cell. In an attempt to test the validity of these assumptions, the required high partition‐coefficients were easily attained by inserting alkyl groups (C1 to C3). But high stability constants are uncommon, and cannot be predicted in advance of synthesis.

In the course of the present work, several substances were examined from this point of view. Of these, 2‐mercaptopyridine‐N‐oxide is the most antibacterial. It has the intense and rapid action of 8‐hydroxyquinoline and acts by the same mechanism (transport of iron).
On the infrared spectrum of urea in the urea‐cetane complex
Authors: Stuart A. A. Verrijn
Published: September 2010

The spectral region of the N‐H stretching, frequencies of the urea‐cetane complex was investigated with the aid of polarized infrared radiation. A dichroism was observed similar to that found by Waldron and Badger in a study of the pure urea crystal. The differences between the two cases are discussed in terms of a “coupled oscillator” model. They are shown to be closely connected with the differences in hydrogen bonding in the crystals, as known from the X‐ray studies of A. E. Smith, and Vaughan and Donohue.
Studies on polarography: I ‐ Reduction of potassium permanganate at the dropping mercury electrode
Authors: Issa I. M. , Khalafalla S. E. , Issa R. M.
Published: September 2010

Reduction of the permanganate ion at the dropping mercury electrode is studied in acid, neutral, and alkaline solutions. As supporting electrolytes KCl, BaCl2, and Ba(NO3)2 together with the constituents of buffer solutions of pH 1, 3, 5, 7, 9, and 12 were used. The polarograms consist each of two waves; the first starts at zero potential and corresponds to the process Mn+7 → Mn+2, except in the phosphate buffer of pH 12. In this phosphate buffer it proceeds as Mn+7 → Mn+3. The second wave corresponding to the process Mn+3 → Mn or Mn+2 → Mn appears at ∼ pH 5 and higher. In alkaline solutions the first wave is split up into smaller waves, possibly corresponding to Mn+7 → M+4, Mn+4 → Mn+3, and Mn+3 → Mn+2.

In acid solutions the Mn+2 → Mn wave disappears and is replaced by a hydrogen wave. Some irregularities observed in alkaline solutions are explained.
Chemistry of the sydnones. II
Authors: Earl J. C.
Published: September 2010

Although the sydnones are converted to hydrazines by hot, moderately concentrated aqueous hydrochloric acid, more dilute acid is without effect on 3‐phenylsydnone. Chlorination and bromination can be effected in aqueous solutions of the corresponding acids, using either the halogens themselves or the alkali chlorates and bromates.
The reactivity of the bromine atom in methylsubstituted nitrobromobenzenes towards piperidine
Authors: van Berk P. , van Langen J. O. M. , Verkade P. E. , Wepster B. M.
Published: September 2010

Reaction rate constants are determined for the piperidino‐debromination of a number of derivatives ofortho‐ andpara‐nitro‐bromobenzene with one or two methyl groups as substituents. The results are discussed and compared with those obtained in the catalytic deacetylation of the corresponding nitroacetylamino compounds in an alkaline medium.
Hydrocarbures polycycliques aromatiques. I. Dérivés de substitution du 3,4‐9,10‐dibenzopyrène
Authors: Buu‐Hoï N. P. , Lavit Denise
Published: September 2010

Il est montré que le 3,4‐9,10‐dibenzopyrène peut être formylé par la N‐méthylformanilide en 5‐formyl‐3,4‐9,10‐dibenzopyrène; le 5‐methyl‐3,4‐9,10‐dibenzopyrène, obtenu par réduction de ce dernier aldéhyde, peut à son tour être formylé, et le 8‐formyl‐5‐méthyl‐3,4‐9,10‐dibenzopyrène ainsi préparé est réductible en 5,8‐diméthyl‐3,4‐9,10‐dibenzopyrène. La réactivité des sommets mésoanthracéniques permet également de préparer le 5,8‐dinitro‐3,4‐9,10‐dibenzopyrène, lequel est réductible en 5,8‐diamino‐3,4‐9,10‐dibenzopyréne avec le chlorure de sulfuryle, on a le 5,8‐dichloro‐3,4‐9,10‐dibenzopyrène.