bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigations on pesticidal phosphorus compounds I. Fungicides, insecticides and acaricides derived from 3‐amino‐1,2,4‐triazole
Authors: van den Bos B. G. , Koopmans M. J. , Huisman H. O.
Published: September 2010

The preparation and the biological properties of a number of compounds with fungicidal, insecticidal and acaricidal activities are described. The compounds were prepared by substitution of a phosphorus containing group for a hydrogen atom of the 1,2,4‐triazole nucleus in 3‐amino‐1,2,4‐triazole or a 5‐ substituted derivative thereof.

Biological activity was highest when the phosphorus containing group was a bis(dimethylamido)phosphoryl group.
Chemistry of acetylenic ethers XLIII: Reactions of oximes with ethoxyethyne
Authors: Tigchelaar‐Lutjeboer H. D. A. , Bootsma H. , Arens J. F.
Published: September 2010

In the reaction of oximes I with ethoxyethyne II at 75‐90° orthoesterlike products III are formed. Some aldoximes, however, are dehydrated to nitriles. The results are summarized in Table I.
Chemistry of acetylenic ethers XLIV: Additions to the ethyl ester and anilide of (Ethylthio)propynoic acid
Authors: Bonnema J. , Alkema H. J. , Arens J. F.
Published: September 2010

The addition of electrophilic reagents to ethyl (ethylthio)propynoate II occurs at carbon atom 2. Uncharged nucleophilic reagents (amines) are also added at carbon atom 2, but charged nucleophiles (ethoxide ion and the carbanion of malonic ester) interact at carbon atom 3. Additions to the anilide of (ethylthio)propynoic acid (XVIII) take a similar course. The results are discussed and explained.
Electro‐osmosis experiments at the germanium/electrolyte interface
Authors: Sparnaaij M. J.
Published: September 2010

Measurements of the electro‐osmotic transport of liquid in the germanium (powder) electrolyte solution were carried out. The results can be explained by a theory, which is given by Verwey and Payens, which was originally proposed for surface layers consisting of weakly ionized fatty acids. In the case of germanium it should be assumed that a weakly ionized germanic acid is present at the surface, giving the surface a negative charge. The experiments almost break down when p‐type Ge is used. This can be explained by potential current characteristics using p‐type or n‐type Ge as the anode.
Alkyl‐substituted benzaldehydes
Authors: Klouwen M. H. , Boelens H.
Published: September 2010

The ortho‐, meta‐ and para‐isomers of methyl‐, ethyl‐, isopropyl‐ and tertiary butylbenzaldehyde have been synthesized for the purpose of an olfactory study

1 To be published.

. The aldehydes were isolated and purified via the semicarbazones. The ultra‐violet absorption spectra of the aldehydes as well as those of the semicarbazones were determined. Particular attention was paid to ortho‐alkylbenzaldehydes as to whether there is any steric effect of mesomerism.
Studies in IVth group organometallic chemistry. VI: Preparation and polymerization of IVth group organometallic derivatives of styrene and α‐methylstyrene
Authors: Noltes J. G. , Budding H. A. , van DerKerk G. J. M.
Published: September 2010

The preparation of a series of IVth group organometallic vinyl monomers derived from styrene and α‐methylstyrene, respectively, is described. Thermal or radical‐initiated polymerization of the styrene derivatives afforded transparent, solid organometal‐substituted polystyrenes. The monomers of the general structure p‐(CH3)3MIVC6H4CH  CH2 display appreciably different rates of radical‐initiated polymerization, in the order Pb > Si > C > Ge>Sn.
Investigations on sterols XVIII: The synthesis and properties of some hydroxylated 9β,10α‐pregnanes
Authors: Westerhof P. , Reerink E. H.
Published: September 2010

The synthesis of 17α‐hydroxy‐9β,10α‐progesterone, 6‐dehydro‐17α‐hydroxy‐9β,10α‐progesterone and some acylates of these compounds, and of 21‐acetoxy‐9β,10α‐progesterone is described.
Rapid determination of vapour‐liquid equilibria
Authors: Smit W. M. , Ruyter J. H.
Published: September 2010

An apparatus for the determination of vapour‐liquid equilibria at constant pressures within the range of 760 to 10 mm Hg is described.

The apparatus can produce eight pairs of samples of coexisting vapour and liquid, evenly distributed over the concentration range in one run within two hours.

As a proof of its operation the results obtained with six binary systems are recorded. The systems investigated are:

Carbon tetrachloride‐benzene.

Carbon tetrachloride‐toluene.

Benzene‐dichloroethane.

n‐heptane‐methylcyclohexane.

methylcyclohexane‐toluene.

n‐decane‐trans‐decahydronapththalene.

The results obtained agree with a thermodynamic criterion which is discussed separately.
End‐to‐end distances in short‐chain molecules as determined by X‐ray diffraction in the liquid
Authors: Holleman Th.
Published: September 2010

The distribution of end‐to‐end distances in liquid short‐chain molecules has been studied by means of X‐ray diffraction. Solutions in n‐decane of α,ω‐diiodo‐n‐alkanes have been investigated.

The distribution of intramolecular I‐I distances in these compounds was obtained by comparing the experimental X‐ray patterns of the diiodides with the pattern of a monoiodide solution having the same iodine‐to‐carbon ratio. Although the smallness of the observed effect renders the conclusions rather uncertain, the results are in general agreement with a distribution function calculated from a simple theoretical model.
Détermination quantitative de groupements quinoniques. Application a une serie de quinones et a un extrait pyridinique de houille
Authors: Delavarenne S. , Halleux A. , Tschamler H.
Published: September 2010

Reductive acetylation has been investigated for the purpose of developing a suitable chemical method for the quantitative determination of quinone groupings in coal extracts. The reaction has been carried out successfully from an analytical point of view on a series of model quinones, either using zinc and acetic anhydride as the reagent, or copper and hydrogen sulphide, followed by acetic anhydride. However, the procedure with zinc failed to give satisfactory results when applied to a pyridine extract of vitrinite, on account of side reactions with nitrogenous groupings in the coal structure, and spurious hydrogenolysis of carbonoxygen bonds due to non‐aprotic conditions. These difficulties were avoided in the reduction with copper. Hence, it was possible to determine that the pyridine extract of a vitrinite having a carbon content of 84.3% contained 0.95% of quinone oxygen. This value represents barely 15% of the total oxygen present in the investigated extract. The sum of hydroxyl and quinone oxygen in the extract represents 60% of the total oxygen. The remainder is thought to be largely in the form of ethers.
The infrared absorption spectra of some aromatic hydroxy‐ketones
Authors: Cullinane N. M. , Woolhouse R. A. , Bailey‐Wood V. V.
Published: September 2010

The infrared spectra of dilute solutions of some hydroxyacetophenones, hydroxybenzophenones and hydroxyacetonaphthones have been measured. The effect of chelation on both the hydroxyl and carbonyl frequencies has been noted.
Oxidation of benzoic acid‐1‐14C to phenol
Authors: Schoo W. , Veenland J. U. , Bigot J. A. , Sixma F. L. J.
Published: September 2010

Using benzoic acid‐1‐14C the position of the hydroxyl group formed in the oxidation of benzoic acid to phenol and carbon dioxide is definitively identified as ortho in relation to the original carboxyl group.
Polarography of alkyl‐substituted 3‐phenyl‐4‐hydroxy coumarins
Authors: van Zanten B. , Th. Nauta W.
Published: September 2010

Among the alkyl substituted 3‐phenyl‐4‐hydroxycoumarins, synthesized to investigate the relationship between chemical structure and biological activity in this class of compounds2, eleven possess one or moreorthosubstituents.

As the steric effects oforthosubstitution can manifest themselves in the polarographic behaviour, the half wave potentials of these compounds were measured and attempts were made to find relationships between the values obtained and to determine the steric effect in each case. In addition, an equation was derived for the first reduction wave in the polarogram and a reaction mechanism for this polarographic reduction is suggested.
1‐chloro‐4‐nitronaphthalene from 1‐amino‐4‐nitronaphthalene
Authors: Bassilios H. F. , Shawki M. , Salem A. Y.
Published: September 2010

Diazotisation of 1‐amino‐4‐nitronaphthalene with hydrochloric acid and sodium nitrite, and decomposition of the diazonium salt by the Sandmeyer or Gattermann reaction, is studied in order to check the work of Franzen and Helvert and of Ferrero and Caflish 4. The compound, m.p. 61°, reported by Franzen and Helvert to be a new 1‐chloro‐4‐nitronaphthalene, creating a new type of isomerism with the known 1‐chloro‐4‐nitronaphthalene, m.p. 85°, has not been found. Improper conditions of diazotisation, e.g., high temperature, or low concentration of hydrochloric acid, as used by Ferrero and Caflish, lead to decomposition with the formation of impure 1‐nitro‐naphthalene, m.p. 58‐61°.
Precipitate impregnated membranes: III. Membrane potentials and the behaviour of ions at the BaSO4‐cellophane membrane
Authors: Hirsch‐Ayalon P.
Published: September 2010

1. The membrane potentials measured at the BaSO4‐cellophane membrane point to selectivity of its permeability, supporting the conclusions drawn from previously reported direct permeation experiments.

2. In the presence of permeating ions other than H+ and OH−, the membrane potential at the BaSO4 membrane is not exclusively dependant on the pH's of the adjacent solutions. Other ions, e.g. K+ and Cl−, may even take over the predominating role in the development of the membrane potential – in non‐quilibrium states.

3. In non‐equilibrium systems with other permeating ions besides H+ and OH−, spontaneous ion redistribution takes place and the system changes towards a Donnan equilibrium. The rate at which these changes take place greatly depends on the composition of the two adjacent solutions. The changes are often very slow.

4. The eventually reached equilibrium state is a (double) Donnan equilibrium. The fact that Donnan equilibria could be established under favorable conditions, is a further proof for the selective permeability of the BaSO4 membrane.

5. An electrochemical hypothesis is given as a possible explanation of the observations on BaSO4 membranes so far described.
Investigations on pyrazine derivatives. VII: On the conversion of pyrazine 2,5‐dicarboxylic acid into some derivatives of 2‐aminopyrazine 5‐carboxylic acid
Authors: Schut W. J. , Mager H. I. X. , Berends W.
Published: September 2010

Pyrazine 2,5‐dicarboxylic acid was prepared by oxidation of 2,5‐dimethylpyrazine with selenium dioxide. 2,5‐Diethoxycarbonylpyrazine appeared to be a suitable starting‐material for the preparation of monocarbamoyl‐ and monocarboxyhydrazide derivatives. Hofmann degradation of 2‐carbamoyl‐5‐ethoxycarbonylpyrazine into 2‐aminopyrazine 5‐carboxylic acid proved to be rather difficult. The monocarboxyhydrazides in this series could be readily converted into acid azides and eventually into pyrazine‐urethanes.
Synthesis of substituted benzophenones by a direct condensation of substituted benzoic acids with benzene in the presence of aluminium chloride
Authors: Reiding D. J. , Th. Nauta W.
Published: September 2010

Condensation of substituted benzoic acids with benzene in the presence of aluminium chloride is found to be possible, in general, only in the case of ortho‐substituted acids. No reaction could be obtained with benzoic acid itself, with meta‐ or para‐toluic acids, or, somewhat unexpectedly, with 2,4,6‐trimethylbenzoic acid.
The system NbCl5‐Nb2O5
Authors: Meyer G. , Oosterom J. F. , van Oeveren W. J.
Published: September 2010

The following three phase equilibria (dependence of pressure on temperature) have been determined in order to find out which compounds occur in the above mentioned system:

magnified image

From these measurements it follows that in all probability NbOCl3 is the only compound occurring in this binary system.

An analytical method has been worked out for the determination of NbCl5 in the presence of NbOCl3.

By extrapolation from the binary‐melt‐diagram, the melting point of NbCl5 is found to be 206.8° ± 0.3°.
Studies in IVth group organometallic chemistry. VII: Synthesis of some hetero‐polymers containing germanium, tin, and lead in the main polymer chain
Authors: Noltes J. G. , van der Kerk G. J. M.
Published: September 2010

It has been shown that di‐p‐styrenyl derivatives of germanium, tin, and lead as well as 1,4‐divinylbenzene and 3,9‐divinylspirobi(meta‐dioxan) react with diphenyltin dihydride to yield linear poly‐addition polymers containing tin or tin and germanium or lead in the main polymer chain. The polymeric products have been characterized by infrared spectroscopy, analytical data and molecular weight.

Reactions of triphenyltin hydride and diphenyltin dihydride with mono‐ and di‐p‐styrenyl derivatives of germanium, tin, and lead yielding monomeric compounds containing two and three hydrocarbon‐linked metal atoms, have also been carried out.
Contact angles; wetting and de‐wetting of mercury: Part III. Contact angles on mercury
Authors: Smolders C. A.
Published: September 2010

In the system mercury/aqueous Na‐decane sulfonate/hydrogen contact angles are obtained by calculation from the three interfacial tensions, and by direct measurement.

Electrocapillary measurements are described, by which the influence of the surface charge (surface potential) on the adsorption of Nadecane sulfonate at the mercury/solution interface is studied.

Using the sessile drop method, equilibrium surface tension data are obtained for all three interfaces, and for different values of the surface potential of the mercury.

Calculated and measured contact angles are in good agreement over a range of concentrations of Na‐decane sulfonate.

The problem of the thickness of the solution layer at the mercury/gas interface is discussed.
The applicability of Hammett's acidity function H0 to solutions in methanol‐water mixtures
Authors: de Ligny C. L. , Loriaux H. , Ruiter A.
Published: September 2010

The dissociation constants of 4‐aminoazobenzene‐4′‐sulphonic acid, 4‐(methylamino)azobenzene‐4′‐sulphonic acid, 4‐(phenylamino)‐azobenzene‐4′‐sulphonic acid, 4‐(dimethylamino)azobenzene‐4′‐sulphonic acid and p‐nitrophenol were determined in water and in several mixtures of methanol and water at 25°. The influence of the percentage of methanol on the dissociation constant differs greatly for the various indicators, even for indicators of the same charge type.

From this it follows that Hammett's acidity function H0 for solutions in mixtures of methanol and water depends on the indicator used for determining H0. Thus, for solutions in mixtures of methanol and water and presumably also in mixtures of water and other non‐electrolytes, H0 is not a useful, unambiguous measure of the acidity.
Steric effects in the electronic spectra of substituted benzophenones. IV. Unsymmetrically substituted methylbenzophenones
Authors: Rekker R. F. , Nauta W. Th.
Published: September 2010

This article gives the experimental results of UV measurements made on an extensive series of unsymmetrically substituted methylbenzophenones in solution (ethanol and iso‐octane). The results obtained are compared with our previously published UV measurements on symmetrically substituted benzophenones and correlated with literature data on the UV absorption of acetophenones.

From this investigation it appears that for the benzophenone series the oscillator strength f is an additive quantity, a fact which is very useful in comparing the various ketones with one another.

The comparison with acetophenone ‐ in which not only f, but also the wavelength of the conjugative absorption band plays a part ‐ supplied useful information on the position of the phenyl rings relative to the CO group.
Chemistry of acetylenic ethers LIV: Addition of diazo compounds to acetylenic ethers and thioethers
Authors: Groen S. H. , Arens J. F.
Published: September 2010

Ethoxyethyne slowly adds diazomethane to yield 4‐ethoxypyrazole I, the structure of which has been proved by synthesis from 1,1,2,3,3‐pentaethoxypropane IV and hydrazine. Ethylthioethyne V, on the contrary, is converted by diazomethane into 3‐ethylthiopyrazole VI, the structure of which has been proved by synthesis from 3‐aminopyrazole X.

Ethyl diazoacetate does not react with ethoxyethyne, but can be added to ethylthioethyne, yielding presumably 5‐ethoxycarbonyl‐3‐ethylthiopyrazole.
Reserpine analogues II
Authors: de Groot S. , Strating J.
Published: September 2010

A new synthesis of cis‐(3H, 12bH)3‐ethoxycarbonyl‐1,2,3,4,6,7,42,12b‐octahydropyrido [2,1‐a]β‐carboline (VIa) is given.
Crystalline 3‐desoxy‐2‐keto‐gluconic acid
Authors: Paerels G. B.
Published: September 2010

The physical constants of crystalline 3‐desoxy‐2‐keto‐D‐ and L‐gluconic acid, prepared according to Kuhn's method

R. Kuhn, D. Weiser and H. Fischer, Ann. 628, 207 (1959).

, are described.
Spectrophotometric assay of α‐tocopherol
Authors: Mulder F. J. , Keuning K. J.
Published: September 2010

The benzene washing procedure for the isolation of unsaponifiable residues has been applied to vitamin E preparations containing α‐tocopheryl esters only.

The isolation procedure is carried out once (after saponification) or twice (before and after saponification). In the solution thus obtained, β‐tocopherol is determined spectrophotometrically; the absorbance at the maximum is corrected for by‐absorption.

By avoiding quantitative extractions and transfers, contact with air is reduced to a minimum; ascorbic acid is used as an antioxidant.
The chemistry of cycloheptatriene: Part II: Reduction of cycloheptatriene to cycloheptadiene and cycloheptene
Authors: Ter Borg A. P. , Bickel A. F.
Published: September 2010

Reduction of cycloheptatriene (I) and cycloheptadiene (II) with 2 equivalents of sodium in liquid ammonia yields ‐ after addition of ethanol ‐ cycloheptadiene and cycloheptene (III), respectively.

These reactions proceed via coloured intermediates. Reduction of I with 4 equivalents of sodium gives only III.

Carbonation of the reaction mixture of I and 2 equivalents of sodium yields a cycloheptadiene monocarboxylic acid whereas no carboxylic acid has formed upon carbonation of the reaction mixture of II and 2 equivalents of sodium.
The autoxidation of isopropylbenzenes to benzoic acids in acid media: III. Side‐reactions and by‐products
Authors: van Helden R. , Bickel A. F. , Kooyman E. C.
Published: September 2010

In the autoxidation of cumenes to benzoic acids at about 140° in butyric acid as solvent and with Co‐ and Mn‐acetates as catalysts the main side‐reaction is the formation of dimethylbenzyl alcohols. It may be suppressed by employing a low hydrocarbon concentration. The carbinols formed are partly dehydrated to α‐methylstyrenes, which are oxidized, via acetophenones, to benzoic acids (about 50%), and to 1‐methyl‐1‐phenylglycol derivatives, which are also oxidized — but less rapidly — to benzoic acids. Evidence is presented that the glycol derivatives are formed by interaction of the α‐methylstyrenes and peroxy radicals.

The solvent is attacked to some extent by the cobalt catalyst, yielding various degradation products. The first step in this reaction is assumed to be the attack of the trivalent Co‐ions on the carboxyl group of the acid, yielding butyroyloxy radicals.

A general scheme, describing the fate of an isopropyl group in the course of the autoxidation is given.
Peptide derivatives related to the active site of some hydrolytic enzymes: I. Syntheses of tetrapeptide ethyl esters containing glutamic acid and serine
Authors: Kienhuis H. , van De Linde A. , van Der Holst J. P. J. , Verweij A.
Published: September 2010

The syntheses of glycyl‐α‐L‐glutamyl‐L‐serylglycine ethyl ester and of glycyl‐α‐L‐glutamyl‐O‐acetyl‐L‐serylglycine ethyl ester are described. The mixed anhydride method and the carbodiimide method were used for condensing together two dipeptide derivatives. The latter were obtained by the azide method.
On the so‐called Auwers‐Skita Rule, The conformational rule, and the isomer sequence rule
Authors: van Bekkum H. , van Veen A. , Verkade P. E. , Wepster B. M.
Published: September 2010

The merits and defects of the so‐called Auwers‐Skita Rule and of the Conformational Rule are discussed. A new rule, the Isomer Sequence Rule, is proposed.
The condensation of ketones and the ethyl hemiacetal of ethyl glyoxylate
Authors: Noltes A. W. , Kögl F.
Published: September 2010

The ethyl hemiacetal of ethyl glyoxylate (ethyl ethoxy‐hydroxyacetate, I) has been found to undergo thermal condensation with various ketones. The new reaction presents a simple method of attaching a hydroxyacetic ester side chain to a carbon atom adjacent to the carbonyl function, giving 2‐hydroxy‐4‐keto‐alkanoic esters. Of several transformations to which these esters are readily accessible the dehydration reaction in particular has been investigated.
Iodo derivatives of 5‐methyl‐1‐phenyl‐1,2,3‐triazolecarboxylic acid
Authors: Bojarska‐Dahlig H. N.
Published: September 2010

1‐(3′‐Iodophenyl)‐5‐methyl‐1,2,3‐triazolecarboxylic acid, 1‐(4′‐iodophenyl)‐5‐methyl‐1,2,3‐triazolecarboxylic acid and 1‐(3′‐4′‐di‐iodophenyl)‐5‐methyl‐1,2,3‐triazolecarboxylic acid were prepared by reacting ethyl acetylacetate with the corresponding 1‐azido‐di‐iodobenzene.

5‐Methyl‐1‐phenyl‐1,2,3‐triazolecarbonyl chloride and 1‐(4′‐iodophenyl)‐5‐methyl‐1,2,3‐triazolecarbonyl chloride were condensed with 3‐amino‐2,4,6‐tri‐iodobenzoic acid, α‐ethyl‐3‐amino‐2,4,6‐tri‐iodohydrocinnamic (iopanoic) acid and α‐ethyl‐3‐amino‐2,4,6‐tri‐iodocinnamic (dehydroiopanoic) acid.
Note on the conversion of the amino group of amino acids into the nitroguanidino group
Authors: Heyboer N. , Visser G. Heymens , Kerling K. E. T.
Published: September 2010

A study has been made of 2‐methyl‐1‐nitroisourea as a reagent for the conversion of amino groups of amino acids into guanidino groups. This reagent has proved its usefulness in modifying the ω‐amino groups of diaminocarboxylic acids in particular. The reaction of 2‐methyl‐1‐nitroisourea with glycine, L‐ornithine and D‐ and L‐lysine to yield nitroguanidinoacetic acid, L‐nitroarginine and D‐ and L‐nitrohomoarginine, respectively, is described.
The isomerization of toluene‐1‐ 14C under the influence of aluminium bromide and hydrogen bromide
Authors: Steinberg H. , Sixma F. L. J.
Published: September 2010

The homogeneous isomerization of toluene‐1‐14C under the influence of aluminium bromide and hydrogen bromide (mole ratio C6H5‐CH3: Al2Br6·HBr = 6:1) proceeds via a series of consecutive 1,2‐shifts of the methyl group. The energy of activation amounts to 21.9 kcal/mole (± 4%).
Intramolecular hydrogen bonds in some substituted aminoalcohols of the trihexyphenidyl‐type
Authors: de Roos A. M. , Bakker G. A.
Published: September 2010

The binding energy of the intramolecular hydrogen bond occurring in a limited series of substituted aminoalcohols was shown spectroscopically to increase from substituted 2‐aminoethanols, through 3‐aminopropanols to 4‐aminobutanols.
On the impedance of galvanic cells: IV. Determination of rate constants of rapid electrode reactions from electrode impedance measurements
Authors: Rehbach M. , Sluyters J. H.
Published: September 2010

If, at one particular frequency, the electrode impedance is plotted in the complex impedance plane at varying bulk concentrations C*ox and C*RED, keeping C*ox = C*RED, a circle is obtained. Moreover, through one of the points measured a semicircle can be drawn with its centre on the real axis.

From the coordinates of the centres of these circles information can be gained on the rate constant of the electrode reaction. The ohmic resistance, the double layer capacity, diffusion polarization and activation polarization may contribute to the impedance of the electrode.

The upper limit of the rate constant ksh that can be measured by this method is valued at 0.65 cm sec−1.
Reactions of 1‐bromo‐2‐phenylethane and aluminium bromide: Part II. Bromine exchange
Authors: Adema E. H. , Sixma F. L. J.
Published: September 2010

The kinetics of the reaction involving the exchange of bromine atoms between 1‐bromo‐2‐phenylethane‐[82Br] and aluminium bromide in carbon disulphide has been studied in the temperature range of −80° to −100°. The energy of activation is 10.6 kcals/mole.

The kinetic results can only be explained if nearly all aluminium bromide is present as the complex C8H9Br: AlBr3.
On the synthesis of mixed‐acid L‐α‐phosphatidylethanolamines
Authors: Daemen F. J. M. , de Haas G. H. , van Deenen L. L. M.
Published: September 2010

The synthesis is described of phosphatidylethanolamine, involving a reaction between γ,β‐diacylglycerol‐L‐α‐iodohydrins and silver benzyl 2‐ phthalimidoethylphosphate. A comparison has been made between (γ‐oleoyl‐β‐stearoyl)‐L‐α‐phosphatidylethanolamine, obtained by this method and (γ‐oleoyl‐β‐stearoyl)‐L‐α‐phosphatidylethanolamine and the structurally isomeric (β‐oleoyl‐γ‐stearoyl)‐L‐α‐phosphatidylethanolamine, both synthesized by a different procedure, previously reported2. The structural identity of the two former compounds was proved by degradation experiments with the β‐fatty acid releasing phospholipase from snake venom. In addition, some physical properties of the enzymatically formed Iysophosphatidylethanolamine have been compared with those of a corresponding lyso compound and a glycol derivative, both synthesized by the method indicated.
Corrections of the theory of the stability of hydrophobic colloids (the specific influence of ions)
Authors: Sparnaay M. J.
Published: September 2010

Calculations are given concerning various corrections upon the potential energy of two colloidal particles at various distances. The corrections arise from the considerations of finite ionic volumes and from the influence upon the dielectric constant of the solvent by added ions. The ionic volume effect is the most important correction. Limits of the applicability of the Derjaguin and Landau‐Verwey and Overbeek theory are given (see section 3.5). The flat plate approximation and 1‐1 electrolyte solutions are considered only. The paper is an extension of an earlier treatment by the author on corrections of the double layer potential 7, 872 (1958) in this Journal.
Ethylene hydrate at high pressures
Authors: van Cleeff A. , Diepen G. A. M.
Published: September 2010

The P‐t projection of the three phase equilibrium, hydrate ‐ liquid ‐ gas, up to pressures of 1000 atm is recorded. An explanation is given for the sharp rise occurring at ∼18° in the slope of the three phase curve HLG.
Synthèse de deux aldols aromatiques, aldéhyde tropique et hydroxy‐3 phényl‐3 propanal
Authors: van Dam Mathieu J. D.
Published: September 2010

Reduction of ethyl 3,3‐diethoxy‐2‐phenylpropionate by LiAlH4, followed by cautious hydrolysis with the help of a cation exchange resin, yields tropic aldehyde (3‐hydroxy‐2‐phenylpropanal). In the same way. 3‐hydroxy‐3‐phenylpropanal (phenaldol)is obtained from 3,3‐dimethoxypropiophenone. Both isomers, the simplest aromatic aldols, are isolated as crystalline dimers (aldolans).
Chemistry of acetylenic ethers. LXI: A simple method for the preparation of acetylenic thioethers, selenoethers and telluroethers (Preliminary publication)
Authors: Brandsma L. , Wijers H. , Arens J. F.
Published: September 2010

The compounds mentioned in the title have been prepared in accordance with the reaction scheme below, in yields between 50 and 75 %.
Synthesis and physiological properties of some heterocyclic‐aromatic sulphides and sulphones: IV Biological investigations
Authors: van Zwieten P. A. , Meltzer J. , Huisman H. O.
Published: September 2010

The acaricidal properties of some new halogen‐substituted heterocyclic‐aromatic sulphides and sulphones are described. As a rule, the adulticidal activity is negligible, though some compounds show interesting ovicidal properties. The sulphides possess a higher ovicidal activity than the sulphones. The pyridyl sulphides are the most active, the thiazolyl sulphides somewhat less, whereas the pyrimidyl and thienyl sulphides are almost inactive. The pyridine‐N‐oxides are also inactive. The polarity of the compounds synthesized seems to exert a considerable influence on the ovicidal properties.
Preparation of indan‐1‐one and 1‐methyl‐4,5‐benzindan‐3‐one
Authors: Rahman Aziz‐Ur , Gastaminza Alicia E.
Published: September 2010

The methods of preparation of indan‐1‐one and 1‐methyl‐4,5‐benzindan‐3‐one have been reviewed; the former has been prepared by Friedel‐Craft's condensation of β‐chloropropionyl chloride and benzene via β‐chloropropiophenone, while the latter was obtained by the cyclisation of β‐2‐naphthylbutyric acid, prepared either, by malonic ester synthesis on α‐chloro‐α‐(2‐naphthyl)ethane or by a Reformatsky reaction on 2‐acetylnaphthalene.
Physical properties of organic thiones: Part IV. The basicity of the thiocarbonyl group in various thiones
Authors: Janssen M. J.
Published: September 2010

The basicities of four N,N‐dimethylthioamides, of thiourea and all the N‐methylated thioureas, of ethylenethiourea, N,N′‐dimethylethylenethiourea and trimethylenethiourea, of S‐methyl N,N‐dimethyldithiocarbamate and ‐dimethyl trithiocarbonate, were determined. Measurements were made spectrophotometrically in aqueous sulphuric acid of various strengths and attempts were made to correct the absorption values for solvent effects. In methylated thioureas both electronic and steric effects influence the acidity constants. These effects appear to be of comparable magnitude. The results on the dithiocarbamate and trithiocarbonate show that in these compounds the basicity is determined by the negative inductive rather than by the positive mesomeric effect of the methylmercapto group. The amino group exerts a strong mesomeric action as expected.
Molecular volumes of selected boron‐containing compounds
Authors: Waugh John L. T. , Christopher Phoebus M.
Published: September 2010

By the use of a table of self‐consistent atomic parachor constants, which includes the value of 51.9 for boron, the calculated molar parachors for a variety of compounds of this element are found to be in close agreement with observed results. Equations relating the parachor to boiling point, critical temperature, critical volume, and critical pressure are derived for the n‐alkyl borates. Isothermal compressibilities are calculated for all of the compounds included in the present study.
Slow oxidation of hydrocarbons in the gas phase II. Neopentane
Authors: Zeelenberg A. P.
Published: September 2010

The slow oxidation of neopentane has been investigated in a static system at 260°. Analysis by means of gas‐liquid chromatography (GLC) during the early stages of the combustion showed the presence of isobutene, acetone, isobutyraldehyde, pivalaldehyde, methanol, neopentyl alcohol, isobutene oxide, 3,3‐dimethyloxetane, propene, carbon dioxide, acetaldehyde, propene oxide, isopropyl alcohol, t‐butyl alcohol and water.

The formation of these products can be rationalized by a mechanism involving oxidation cycles with occasional chain branching. Oxidation cycles are thought to consist of three distinct steps, viz. (I) Oxygenation of alkyl radicals to yield peroxy radicals, (II) Intramolecular decomposition of peroxy radicals with formation of products and oxy radicals and (III) Interaction of the latter with the hydrocarbon to yield hydroxylic products and alkyl radicals. It would appear that in step (II) a C‐C bond is broken more readily than a C‐H bond. Chain branching is assumed to proceed via the hydroperoxide.

Isomerization of neopentyl radicals and dimerization reactions of radicals do not occur.
Diels‐alder reactions of o‐nitronitrosobenzene and 3‐nitro‐4‐nitrosotoluene
Authors: Hamer Jan , Bernard Robert E.
Published: September 2010

o‐Nitro‐nitrosobenzene and 3‐nitro‐4‐nitrosotoluene were reacted with 1,3‐butadiene and 2,3‐dimethyl‐1,3‐butadiene to form 3,6‐dihydro‐1,2‐oxazines, in high yields.

Infrared spectra, measured in KBr pellets, of starting materials and adducts indicate coplanarity of the nitrogroup and the benzene ring for the starting materials, and considerable steric inhibition of the mesomeric interaction between the nitro group and the benzene ring for the adducts.
Polysaccharides, lipids and poly‐β‐hydroxybutyrate in microorganisms
Authors: Mulder E. G. , Deinema Mia H. , van Veen W. L. , Zevenhuizen L. P. T. M.
Published: September 2010

The occurrence, formation and utilization of polysaccharides, lipids and poly‐β‐hydroxybutyrate in micro‐organisms have been investigated. Bacteria belonging to the genus Arthrobacter were found to accumulate within their cells large amounts (up to 70% of their dry weight) of carbohydrates consisting mainly of polysaccharides.

Yeast cells belonging to the Rhodotorulaceae synthesized large amounts of intra‐cellular lipids (up to 50%). Some species in addition produced considerable quantities of extra‐cellular lipids. The composition of intra‐ and extra‐cellular lipids differed in their component fatty acids and alcohols.

Poly‐β‐hydroxybutyrate was found to occur, in an amount of 30% of the dry cell weight, in the sewage bacterium Sphaerotilus natans; it was also detected in related sheath‐forming bacteria.

These polymeric compounds were synthesized under more or less similar cultural conditions viz. excess of glucose and deficiency of nitrogen.

Lipids and presumably poly‐β‐hydroxybutyrate may be reserve materials, serving as substrates for endogenous metabolism. The function of polysaccharides is less clear.
Electrochemical properties of a new glass electrode containing beryllium oxide II. The responsiveness of the glass electrode to other ions than the protons
Authors: Mans A. E. , Kateman Miss I.
Published: September 2010

A previously published research 2 with membranes of a BeO‐containing glass was continued. Electrodes of the glass in question show increasing responsiveness to monovalent cations according to the series:

C3H7(NH3)+ < Li+ < Na+ < NH4+ < K+ < Rb+ < Ag+ < H+.

In alkaline solutions, which may contain considerable amounts of Na+ by the side of K+, the glass electrodes are very suitable for the determination of the pK. The responsiveness of the electrodes to K+ and to the other monovalent cations can be expressed as a characteristic constant.
The thermal decarboxylation of alkali trichloroacetates in aprotic solvents III
Authors: Wagner W. M. , Kloosterziel H. , Bickel A. F.
Published: September 2010

Thermal decomposition of sodium trichloroacetate in 1,2‐dimethoxyethane in the presence of various perchloro compounds leads to α,β‐elimination of chlorine from these compounds and formation of CCl4. Hexachlorocyclopentadiene yields decachlorobi‐(2,4‐cyclopentadien‐1‐yl)

These results point to a mechanism involving Cl+‐abstraction by the CCl3−ion.
Aromatic sulphonation IV Kinetics and mechanism of the sulphonation of benzene in aqueous sulphuric acid
Authors: Kaandorp A. W. , Cerfontain H. , Sixma F. L. J.
Published: September 2010

The kinetics of the sulphonation of benzene have been measured at 5.0°, 25.0° and 45.0° in aqueous sulphuric acid solutions, varying from 77.6 to 99.2 wt‐% H2SO4In addition, sulphonation rate measurements have been made at 5.0° in 98.8 wt‐% H2SO4containing various concentrations of sodium bisulphate. All reactions were found to be first order with respect to benzene. The kinetics are discussed in terms of the mechanism:

magnified image

It is suggested that sulphur trioxide or, though less probable, the sulphuric acid solvate of sulphur trioxide SO3(H2SO4) or disulphuric acid (H2S2O7), is the sulphonating entity X and thatk1 <k2|B|+k3No kinetic distinction can be made between the deprotonation by reaction [2] and the less probable intramolecular proton shift (reaction [3]).

A comparison between the mechanisms of sulphonation in aqueous and fuming sulphuric acid furnishes additional evidence that SO3, instead of SO3(H2SO4) or H2S2O7, should be regarded as the sulphonating entity.
Syntheses with metallated thioacetals and orthothioformates
Authors: Fröling A. , Arens J. F.
Published: September 2010

Thioacetals and orthothioformates, compounds having the general formula HC(R)(SR′)2 with R = H, SR′, CH3, or C6H5 and R′ = C2H5 or C6H5, were metallated by means of alkali amides in liquid ammonia. The metallated derivatives were A) alkylated, B) converted with ketones (successfully only when R = H and R′ = C6H5), and C) ethylthiolated by means of diethyldisulphide (only when R = H, SR′, or C6H5). The results of the reactions are summarized in Tables I‐VI, VIII, and IX. Similar conversions were impossible with common acetals or orthoformates (notably CH2(OC2H5)2, C6H5‐CH(OC2H5)2, and CH(OC2H5)3). The easy metallation of the thiocompounds is attributed to d‐orbital participation of sulphur, which probably lowers the activation energy of the metallation reaction and enhances the stability of the carbanions.

The new reactions in principle enable the synthesis of aldehydes from formaldehyde, of methyl ketones from acetaldehyde, of phenyl ketones from benzaldehyde, and of carboxylic acids from formic acid.

Upon standing, solutions of NaC(SC2H5)3 and NaC(SC6H5)3 in liquid ammonia slowly decompose, yielding compounds of the type (R′S)2C = C(SR′)2. The transient occurrence of a carbene: C(SR′)2, formed by splitting‐off of thiolate from the carbanion ⊖ C(SR′)3, is discussed.
Dihydroquinolones I: Reactions of substituted 4‐oxo‐1,2,3,4‐tetrahydroquinoline
Authors: Speckamp W. N. , Pandit U. K. , Huisman H. O.
Published: September 2010

The main product of cyclisation of N‐(m‐methoxyphenyl)‐N‐tosyl‐2‐aminopropionyl chloride is shown to be N‐tosyl‐7‐methoxy‐4‐oxo‐1,2,3,4‐tetrahydroquinoline. The 3‐cyano‐3‐methyl derivative of this quinolone, which was obtained from the latter in two steps, underwent a base catalyzed ring cleavage during an attempted Stobbe condensation. A mechanism for this cleavage reaction has been suggested.
A simple laboratory scale preparative method for dialkyl sulphides, selenides, tellurides, thiols and selenols
Authors: Brandsma L. , Wijers H. E.
Published: September 2010

The preparation of dialkyl sulphides, selenides and tellurides by alkylating sodium sulphide, selenide or telluride, obtained from sodium and sulphur, selenium or tellurium in liquid ammonia, is very easily carried out and gives good yields. It is also possible to prepare and alkylate sodium disulphide and diselenide in liquid ammonia. The resulting dialkyl disulphides and diselenides in the reaction mixture can be converted simply and in good yields into the corresponding thiols and selenols.
On the impedance of galvanic cells: V. The impedance of a galvanic cell with two plane parallel electrodes at short distance
Authors: Sluyters J. H.
Published: September 2010

It is shown both by calculation and experimentally that in a galvanic cell with two plane electrodes, through which an alternating current flows, the concentration waves interfere if the distance of the electrodes is of the order of a wave length.
A note on the preparation of chloro‐dialkylphosphines
Authors: Voskuil W. , Arens J. F.
Published: September 2010

Chloro‐dialkylphosphines, R2PCl (R = branched primary, secondary or tertiary alkyl group), can be easily prepared from phosphorus trichloride and alkylmagnesium chlorides in ether.
Foam‐fractionation applied to the nonionic detergent nonidet P 40
Authors: Prins A.
Published: September 2010

The nonionic detergent Nonidet P 40 as made from iso‐octylphenol and ethylene oxide is a mixture of polymers with a divergent ethylene oxide content. It is possible to separate it into components with differing ethylene oxide contents by foam‐fractionation.

A solution of a nonionic detergent like Nonidet P 40 in water separates into two phases when the temperature is raised. This cloud point is a measure of the ethylene oxide content of the soap. Use is made of this fact in the analysis of the foam‐fractions.
On the superimposability of the electronic spectra of disubstituted benzene derivatives in the interpretation of the principal absorption bands of certain trisubstituted derivatives
Authors: Rekker R. F. , Nauta W. Th.
Published: September 2010

The validity of a superimposability principle for the electronic spectra of disubstituted benzene derivatives, proposed byDoubandVandenbelt5to interpret the principal absorption bands of some trisubstituted benzene derivatives is discussed forp‐aminosalicylic acid, β‐resorcylic acid and 2‐amino‐5‐chlorobenzoic acid.
Mechanism of reactions of unsaturated ethers and thioethers. VII: Linear free energy relationships and inverse secondary deuterium isotope effect in the addition of water to 1‐alkynyl thioethers
Authors: Hogeveen H. , Drenth W.
Published: September 2010

The effect of structure on the rates of hydration was analyzed with the Taft equation log k = ϱ*σ* + constant, for the following two series:

HCCSR′, with R′ = C2H5, CH(CH3)2> and C(CH3)3, log kR′ = −0.73σR′* −0.75;

RC  CSC2H5, with R = CH3, C2H5, CH2CH2CH3> and CH(CH3)2, log kR = −3.76σR* −2.07.

The values of the polar reaction constants are in agreement with the established mechanism of this reaction.

The kinetic experiments with HCCSC2H5 and DCCSC2H5 revealed an inverse secondary deuterium isotope effect: kD/kH = 1.03. This value, was compared with those calculated either from the alterations of the vibrations during the reaction or from the difference in inductive effect of H and D.
Mechanism of reactions of unsaturated ethers and thioethers. IX: Acid‐catalyzed alkyl oxygen fission of alkyl ethynyl ethers
Authors: Stamhuis E. J. , Drenth W.
Published: September 2010

As in the formation of esters from alkyl ethynyl ethers with primary alkyl groups by addition of water, isopropyl and tert.‐butyl acetate are produced from isopropoxy‐ and tert.‐butoxyethyne. In addition, the latter ethers show formation of an acidic product and an olefin.

A mechanism is proposed in which the first step is a rate determining proton‐transfer to the triple bond:

The carbonium ion formed initially reacts in two ways. One is by addition of water leading to the production of ester. The other is an alkyl oxygen fission from which keten and an alkyl carbonium ion result. The keten is rapidly converted into acetic acid. The alkyl carbonium ion is stabilized among other things by olefin formation.

Rate constants for HCCOR, as R is varied, obey the Taft equation: log kR = ϱ*σR* + constant. The polar reaction constants, ϱ*, have exceptionally large values of approximately −7.
Preparation of adipic acid by oxidation of cyclohexanol and cyclohexanone with nitric acid: Part III. Reaction kinetics of the oxidation
Authors: van Asselt W. J. , van Krevelen D. W.
Published: September 2010

The reaction velocity of the oxidation of cyclohexanol and cyclohexanone with nitric acid (without a catalyst) can be calculated from the chromato‐graphically measured change in the concentration of some of the reaction products: nitrolic acid and adipic acid.

The oxidation reaction appeared to be first order in cyclohexanone, which rapidly forms in the oxidation of cyclohexanol. The oxidation rate can be calculated by means of a simple empiric formula.

The catalysts NH4VO3 and Cu(NO3)2 do not affect the oxidation rate proper. The rate at which Dione decomposes into adipic acid (kv) in the presence of vanadate can be calculated from the increase of the adipic acid concentration. If vanadate is absent, an impression of the rate at which Dione is further oxidized into by‐products (kH) can be obtained from the increase of the glutaric acid and succinic acid concentrations.
The constitution of the Grignard reagent
Authors: Vreugdenhil A. D. , Blomberg C.
Published: September 2010

Experiments are reported on the association number of magnesium bromide, diethylmagnesium, mixtures of these two compounds, the Grignard reagent prepared from magnesium and ethyl bromide and mixtures of this Grignard reagent with magnesium bromide, all dissolved in pure diethyl ether at concentrations from 10−3 to 10−2 molar and measured at the same temperature.

No trace of the equilibrium:

was observed.

Only one magnesium atom is incorporated in the molecules of the Grignard reagent, even in the presence of a large amount of magnesium bromide.
On the synthesis of isomeric lysophosphatides
Authors: Slotboom A. J. , de Haas G. H. , van Deenen L. L. M.
Published: September 2010

The synthesis is described of two isomeric lysophosphatidylethanolamines, containing the fatty acid residue in the γ‐ and β‐ester position, respectively. The preparation of the (β‐stearoyl)‐DL‐α‐lysophosphatidylethanolamine was accomplished by two procedures. According to the first method developed, a silver iodide interchange reaction was carried out between γ‐O‐benzyl‐β‐stearoylglycerol‐α‐iodohydrin and silver benzyl 2‐phthalimidoethyl phosphate. This procedure was also applied for the synthesis of (γ‐stearoyl)‐DL‐α‐lysophosphatidyl‐ethanolamine by starting from γ‐stearoyl‐β‐O‐benzylglycerol‐α‐iodohydrin. A second method involved the preparation of silver benzyl γ‐O‐benzyl‐β‐stearoyl‐α‐glycerol phosphate which was coupled with 2‐iodoethylphthalimide. This pathway also furnishes several intermediates which are suitable for the preparation of other types of lysophosphatides. A distinction between both structurally isomeric lysophosphatidyl‐ethanolamines by enzymic means proved to be possible. Phospholipase A from snake venom was shown to release the fatty acid constituent from the β‐acyl isomer, whereas the γ‐acyl isomer was not susceptible to the action of this enzyme.
A convenient method for the preparation of vinylacetylene on a laboratory scale
Authors: de Vries G. , Peer H. G.
Published: September 2010

Dehydrochlorination of the di‐chloro addition products of butadiene‐1.3 by means of KOH offers an attractive route to vinylacetylene.
On the impedance of galvanic cells: VI Alternating current polarography in the complex impedance plane: General treatment
Authors: Sluyters‐Rehbach M. , Sluyters J. H.
Published: September 2010

The views developed in parts III and IV of this series are applied to alternating current polarography in the impedance plane. It is shown that from such polarograms a quantity q can be determined which is inversely proportional to concentration. The method covers a concentration range of 5.10−9/n2<C*<3.10−6/n2 for reversible processes and of 10−10/n2ksh <C*<10−7/n2ksh for irreversible processes.
Tin and lead as selective catalysts in the direct synthesis of methylchlorosilanes
Authors: Voorhoeve R. J. H. , Vlugter J. C.
Published: September 2010

In this paper experiments are described in which tin and lead are used as selective catalysts for the synthesis of methyltrichlorosilane (80‐90% yield) and methyldichlorosilane (72% yield), respectively. For the methyltrichlorosilane synthesis, the reaction velocity is given as a function of temperature and conversion of methyl chloride at atmospheric pressure.